No dealer, salesperson or other person is authorized to give any information or to represent as to anything not contained in this prospectus or in any free writing prospectus we may authorize to be delivered or made available to you. You must not rely on any unauthorized information or representations. This prospectus is an offer to sell, and we are seeking offers to buy, only the ordinary shares offered hereby, and only under circumstances and in jurisdictions where it is lawful to do so. The information contained in this prospectus is current only as of its date, regardless of the time of delivery of this prospectus or any sale of the ordinary shares.

Neither we nor the underwriters have done anything that would permit this offering or the possession or distribution of this prospectus or any filed free writing prospectus in any jurisdiction where other action for that purpose is required, other than in the United States. Persons outside the United States who come into possession of this prospectus or any free writing prospectus filed with the U.S. Securities and Exchange Commission, or SEC, must inform themselves about, and observe any restrictions relating to, the offering of the ordinary shares and the distribution of this prospectus or any filed free writing prospectus outside of the United States.

Until      , 2021 (the 25th day after the date of this prospectus), all dealers that buy, sell or trade ordinary shares, whether or not participating in this offering, may be required to deliver a prospectus. This is in addition to the obligation of dealers to deliver a prospectus when acting as underwriters and with respect to their unsold allotments or subscriptions.

This prospectus is not a prospectus for the purposes of the Irish Companies Act 2014, the European Union (Prospectus) Regulations 2019 of Ireland (as amended) or the Prospectus Rules issued by the Central Bank of Ireland and the Central Bank of Ireland has not approved this prospectus.

Prior to the completion of this offering, we will undertake a corporate reorganization described under the section titled “Corporate Reorganization,” pursuant to which GH Research Ireland Limited will become a wholly owned subsidiary of GH Research PLC.

Unless otherwise indicated or the context otherwise requires, all references in this prospectus to the terms “the company,” “we”, “us” and “our” refer to (i) GH Research Ireland Limited prior to the completion of our Corporate Reorganization (as defined herein) and (ii) GH Research PLC (and, where the context requires, its subsidiary) following the completion of the Corporate Reorganization.

We maintain our books and records in euro, our results are subsequently converted to U.S. dollars and we prepare our financial statements in accordance with generally accepted accounting principles in the International Financial Reporting Standards, or IFRS, as issued by the International Accounting Standards Board, or IASB. The terms “dollar,” “USD” or “$” refer to U.S. dollars and all references to “€” are to Euro.

We have historically conducted our business through GH Research Ireland Limited, and therefore our historical financial statements present the results of operations of GH Research Ireland Limited. Following the completion of this offering, and after the completion of the transactions described under the section titled “Corporate Reorganization,” our financial statements will be prepared on a consolidated basis and will present the consolidated results of operations of GH Research PLC and its subsidiary GH Research Ireland Limited.

This financial information should be read in conjunction with “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and our financial statements and related notes included elsewhere in this prospectus.

This prospectus contains industry, market and competitive position data that are based on general and industry publications, surveys and studies conducted by third parties, some of which may not be publicly available, and our own internal estimates and research. Third-party publications, surveys and studies generally state that they have obtained information from sources believed to be reliable, but do not guarantee the accuracy and completeness of such information. These data involve a number of assumptions and limitations and contain projections and estimates of the future performance of the industries in which we operate that are subject to a high degree of uncertainty. We caution you not to give undue weight to such projections, assumptions or estimates.

We have made rounding adjustments to some of the figures included in this prospectus. Accordingly, numerical figures shown as totals in some tables may not be an arithmetic aggregation of the figures that preceded them.

Investing in our ordinary shares involves a high degree of risk. You should carefully consider the following risks and uncertainties, together with all other information in this prospectus, including our financial statements and related notes and “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” before investing in our ordinary shares. Any of the risk factors we describe below could adversely affect our business, financial condition or results of operations. The market price of our ordinary shares could decline if one or more of these risks or uncertainties actually occur, causing you to lose all or part of your investment. Additional risks that we currently do not know about or that we currently believe to be immaterial may also impair our business and the market price of our ordinary shares. Certain statements below are forward-looking statements. See the section titled “Cautionary Statement Regarding Forward-Looking Statements” appearing elsewhere in this prospectus.

Investment in biopharmaceutical product development is highly speculative because it entails substantial upfront capital expenditures and significant risk that any potential product candidate will fail to demonstrate adequate effect or an acceptable safety profile, gain regulatory approval or become commercially viable. We have no products approved for commercial sale and have not generated any revenue to date, and we will continue to incur significant research and development and other expenses related to our clinical development and ongoing operations. As a result, we are not profitable and have incurred losses in each period since our inception. Since our inception, we have devoted substantially all of our financial resources and efforts to research and development, including nonclinical studies and our clinical trials. Our financial condition and operating results, including net losses, may fluctuate significantly from quarter to quarter and year to year. Accordingly, you should not rely upon the results of any quarterly or annual periods as indications of future operating performance. Additionally, net losses and negative cash flows have had, and will continue to have, an adverse effect on our shareholders’ (deficit)/equity and working capital. Our net losses were $1,149 thousand, $446 thousand and $310 thousand for the three months ended March 31, 2021 and the years ended December 31, 2020 and 2019, respectively. As of March 31, 2021, we had an accumulated deficit of $2 million. We expect to continue to incur significant losses for the foreseeable future, and we expect these losses to increase as we continue our research and development of, and seek regulatory approvals for, our product candidates in our initial and potential additional indications as well as for other product candidates.

We anticipate that our expenses will increase substantially if and as we:

Our expenses could increase beyond our expectations if we are required by the U.S. Food and Drug Administration, or the FDA, or other comparable foreign regulatory authorities, to perform clinical trials in addition to those that we currently expect, or if there are any delays in establishing appropriate manufacturing arrangements for our product candidates or for the medical devices required to deliver our product candidates, or if there are any delays in completing our clinical trials or the development of any of our product candidates or of the medical devices required to deliver our product candidates.

We expect to spend substantial amounts to continue the nonclinical and clinical development of our current and future programs. Even if this offering is successful, if we are able to gain marketing approval for product candidates that we develop, including any indication for which we are developing or may develop our GH001 and GH002 product candidates, we may require additional amounts of cash in order to launch and commercialize such product candidates and the medical devices required to deliver such product candidates to the extent that such launch and commercialization is not the responsibility of a future collaborator that we may contract with in the future. In addition, other unanticipated costs may arise in the course of our development efforts. Because the design and outcome of our planned and anticipated clinical trials is highly uncertain, we cannot reasonably estimate the actual amounts necessary to successfully complete the development and commercialization of any product candidates we develop.

Our future capital requirements depend on many factors, including:

We cannot be certain that additional funding will be available on acceptable terms, or at all. We have no committed source of additional capital and if we are unable to raise additional capital in sufficient amounts or on terms acceptable to us, we may have to significantly delay, scale back or discontinue the development or commercialization of our product candidates or other research and development initiatives. Any of our current or future license agreements may be terminated if we are unable to meet the payment or other obligations under the agreements.

We expect our expenses to increase in connection with our planned operations. Until such time, if ever, that we can generate substantial product revenues, we expect to finance our cash needs through a combination of equity offerings, debt financings, convertible debt financings, strategic collaborations and licensing arrangements. In addition, we may seek additional capital due to favorable market conditions or strategic considerations, even if we believe that we have sufficient funds for our current or future operating plans.

To the extent that we raise additional capital through the sale of equity or convertible debt securities, your ownership interest may be diluted, and the terms of these securities could include liquidation or other preferences and anti-dilution protections that could adversely affect your rights as a shareholder. Debt financing, if available, may result in fixed payment obligations and may involve agreements that include covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures, creating liens, redeeming shares or declaring dividends, that could adversely impact our ability to conduct our business. In addition, securing financing could require a substantial amount of time and attention from our management and may divert a disproportionate amount of their attention away from day-to-day activities, which may adversely affect our management’s ability to oversee the development of our product candidates.

If we raise additional funds through strategic collaborations or marketing, distribution, licensing and royalty arrangements with third parties, we may have to relinquish valuable rights to our intellectual property or technologies, future revenue streams, research programs or product candidates or to grant licenses on terms that may not be favorable to us or issue and sell our shares, which may result in dilution to our shareholders. If we are unable to raise additional funds through equity or debt financings when needed, we may be required to delay, limit, reduce or terminate our product development or future commercialization efforts or grant rights to develop and market product candidates that we would otherwise prefer to develop and market ourselves.

We are a clinical-stage biopharmaceutical company with a very limited operating history, focused on novel therapies which may be able to induce ultra-rapid and durable remissions in patients with depression and in other indications within our focus area of psychiatric and neurological disorders. We commenced operations in 2018, have no products approved for commercial sale, and have not generated any revenue from product sales. Drug development is a highly uncertain undertaking and involves a substantial degree of risk. We are conducting a Phase 1/2 clinical trial for GH001 and have not initiated clinical trials for any other product candidates. The results of clinical trials with smaller sample sizes and shorter follow-up, such as our completed Phase 1 clinical trial in 22 healthy volunteers and our ongoing Phase 1/2 clinical trial in 16 planned patients with TRD, both with seven days follow-up, can be disproportionately influenced by various biases associated with the conduct of small short-term clinical trials, such as the potential failure of the smaller sample size to accurately depict the features of the broader patient population, and the potential failure of shorter studies to accurately depict long-term safety and efficacy results, which limits the ability to generalize the results, thus making the clinical trial results less reliable than clinical trials with a larger number of patients and longer follow-up. As a result, there may be less certainty that such product candidate would achieve a statistically significant effect in any future clinical trials. If we conduct any future clinical trials of GH001, we may not achieve a statistically significant result or the same level of statistical significance, if any, that we might have anticipated based on the results observed in our initial Phase 1 and Phase 1/2 clinical trials. To date, our clinical trials have been conducted only in the Netherlands, and we have not initiated or completed a pivotal clinical trial, obtained marketing approval for any product candidates, manufactured a commercial scale product or arranged for a third party to do so on our behalf, or conducted sales and marketing activities necessary for successful product commercialization. Our short operating history as a company makes any assessment of our future success and viability subject to significant uncertainty. We will encounter risks and difficulties frequently experienced by early-stage biopharmaceutical companies in rapidly evolving fields, and we have not yet demonstrated an ability to successfully overcome such risks and difficulties. If we do not address these risks and difficulties successfully, our business will suffer.

We currently have one product candidate in clinical development and one product candidate in preclinical development. The development of these programs and product candidates, of the medical devices required to deliver these product candidates and of any potential future programs and product candidates require significant capital investment. Due to the significant resources required for the development of our programs and product candidates, we must focus our programs and product candidates on specific diseases and disease pathways and decide which product candidates to pursue and advance and the amount of resources to allocate to each. Our drug development strategy is to clinically test and seek regulatory approval for our product candidates in indications in which we believe there is the most evidence that we will be able to efficiently generate proof-of-concept data. We then intend to expand to clinical testing and seek regulatory approvals in other psychiatric and neurological disorders. However, even if our product candidates are able to gain regulatory approval in one indication, there is no guarantee that we will be able to expand to other indications, and we may expend significant resources in seeking such approvals.

In addition, we may focus resources on pursuing indications outside of psychiatric and neurological disorders based on the same strategic approach (e.g., mechanistic rationale, the availability of translational tools, clinical development path, commercial opportunity) we utilize in determining on which

of our discovery programs to focus. Our decisions concerning the allocation of research, development, collaboration, management and financial resources toward particular product candidates or particular medical devices to deliver those product candidates, or therapeutic areas may not lead to the development of any viable commercial product and may divert resources away from better opportunities. Additionally, we may reprioritize product candidate development plans and activities at any time and delay or terminate development of any product candidates we identify. Similarly, our potential decisions to delay, terminate, or collaborate with third parties in respect of certain programs, product candidates, or medical devices to deliver those product candidates may subsequently also prove to be suboptimal and could cause us to miss valuable opportunities. If we make incorrect determinations regarding the viability or market potential of any of our programs or product candidates or misread trends in the biopharmaceutical industry, in particular for psychiatric and neurological disorders, our business, financial condition, and results of operations could be materially adversely affected. As a result, we may fail to capitalize on viable commercial products or profitable market opportunities, be required to forego or delay pursuit of opportunities with other product candidates or other diseases and disease pathways that may later prove to have greater commercial potential than those we choose to pursue or relinquish valuable rights to such product candidates through collaboration, licensing or other royalty arrangements in cases in which it would have been advantageous for us to invest additional resources to retain sole development and commercialization rights.

Due to the international scope of our operations, our assets, earnings and cash flows are influenced by movements in exchange rates of several currencies, particularly the pound sterling, and going forward, by the U.S. dollar, as we expand our operations. Our reporting currency is denominated in U.S. dollars and our functional currency is the euro and the majority of our operating expenses are paid in euro and pound sterling. We also regularly acquire services, consumables and materials in euro and pound sterling. Further potential future revenue may be derived from abroad, particularly from the United States. As a result, our business and the price of our ordinary shares may be affected by fluctuations in foreign exchange rates between the euro and these other currencies, which may also have a significant impact on our results of operations and cash flows from period to period. Currently, we do not have any exchange rate hedging arrangements in place. See Note 3 in the notes to our annual financial statements appearing elsewhere in this prospectus for a description of foreign exchange risks.

In addition, the possible abandonment of the euro by one or more members of the European Union could materially affect our business in the future. Despite measures taken by the European Union to provide funding to certain EU member states in financial difficulties and by a number of European countries to stabilize their economies and reduce their debt burdens, it is possible that the euro could be abandoned in the future as a currency by countries that have adopted its use. This could lead to the reintroduction of individual currencies in one or more EU member states, or in more extreme circumstances, the dissolution of the European Union. The effects on our business of a potential dissolution of the European Union, the exit of one or more EU member states from the European Union or the abandonment of the euro as a currency, are impossible to predict with certainty and any such events could have a material adverse effect on our business, financial condition and results of operations.

We have no products approved for commercial sale. To generate revenues from the sales of any approved products that are significant or large enough to achieve profitability, we must succeed, either alone or with third parties, in developing, obtaining regulatory approval for, manufacturing, and marketing therapies with significant commercial success. Our ability to generate revenue and achieve profitability depends on many factors, including:

Because of the numerous risks and uncertainties associated with drug and drug-device combination product development, we are unable to predict the timing or amount of our expenses, or when we will be able to generate any meaningful revenue or achieve or maintain profitability, if ever.

We have concentrated our research and development efforts on GH001 and GH002 for the treatment of psychiatric or neurological disorders and our future success depends on our successful development of these product candidates. Our risk of failure is high. We may experience problems or delays in developing GH001 and GH002. Any such problems or delays would cause unanticipated costs, and any development problems may not be solved. For example, we or another party may uncover a previously unknown risk associated with GH001 and GH002 that may be more problematic than we currently believe, and this may prolong the period of observation required for obtaining, or result in the failure to obtain, regulatory approval or may necessitate additional clinical testing.

In addition, the product specifications and the clinical trial requirements of the FDA, the European Commission, the EMA, and other regulatory authorities and the criteria these regulators use to determine

the safety and efficacy of a product candidate vary substantially according to the type, complexity, novelty and intended use and market of such product candidate. The regulatory approval process for novel product candidate such as ours is unclear and can be more expensive and take longer than for other, better known or more extensively studied therapies. For example, because our GH001 and GH002 product candidates contain 5-MeO-DMT, which is categorized as a Schedule I controlled substance under the CSA, a Schedule 1 drug under the United Kingdom’s Misuse of Drugs Regulations 2001 and is similarly categorized by most states, foreign governments and the UN Convention on Psychotropic Substances, 1971, the development towards regulatory approval of GH001 and GH002 is especially challenging and uncertain. The high technical complexity of the development of drug-device combination products further increases risks and uncertainties towards regulatory approval of our product candidates. This risk and uncertainty is particularly high in the area of drug-device combination products for inhaled delivery of the drug component, such as with GH001. In the past, drug-device combination products have experienced significant delays due to technical challenges faced in achieving the tight technical performance specifications required for regulatory approval, or due to specific adverse events associated with inhaled delivery. We anticipate that GH001 and the device required to deliver GH001 will require significant additional technical development work before it achieves adequate technical performance specifications to allow regulatory approval. It is uncertain whether this development work will be successful. To our knowledge, no 5-MeO-DMT therapies have received FDA approval nor received marketing authorization from the European Commission. As a result, it is difficult to determine how long it will take or how much it will cost to obtain regulatory approvals for GH001 and GH002 in either the United States or the European Union. Approvals by the European Commission may not be indicative of what the FDA may require for approval and vice versa.

We currently have no products approved for sale and invest the majority of our efforts and financial resources in the development of our lead product candidates, GH001 and GH002, for the treatment of psychiatric or neurological disorders. Successful continued development and ultimate regulatory approval of GH001 and GH002 for our initial and potential additional indications is critical to the future success of our business. We will need to raise sufficient funds for, and successfully enroll and complete, our clinical development programs of our GH001 and GH002 product candidates for the treatment of TRD and potentially other psychiatric and neurological disorders.

Before we can generate any revenue from sales of GH001, GH002 or any other approved product, we must undertake additional technical, nonclinical and clinical development, regulatory review and approval in one or more jurisdictions for the product candidates and the medical devices required to deliver these product candidates. To date, our clinical trials have been conducted exclusively in the Netherlands. We plan to pursue clinical trials in multiple European countries, Canada, and the United States for all of our clinical programs. We have not submitted Investigational New Drug applications, or INDs, or other comparable applications, for any of our product candidates, including the medical devices to deliver our product candidates, with the FDA, EMA, or other comparable foreign regulatory authorities, outside of the Netherlands. We do not expect that we need to submit separate Investigational Device Exemption applications, or IDEs, or other comparable applications, with the FDA, EMA or other comparable foreign regulatory authorities for the medical devices to deliver our product candidates, and we have not done so, though there can be no assurance that IDEs or comparable applications will not be necessary in the future. In addition, if one or more of our product candidates are approved, we must ensure access to sufficient commercial manufacturing capacity for the product candidates and the medical devices required to deliver these product candidates and conduct significant marketing efforts in connection with any commercial launch, as well as obtaining pricing and reimbursement authorizations in individual European and other countries. These efforts will require substantial investment, and we may not have the financial resources to continue development of our product candidates or commercialization of any products.

We may experience setbacks that could delay or prevent regulatory approval of our product candidates, including the medical devices to deliver our product candidates or our ability to commercialize any products, including:

We do not have complete control over many of these factors, including certain aspects of technical drug product and device development, clinical development and the regulatory submission process, potential threats to our intellectual property rights and our manufacturing, marketing, distribution and sales efforts or that of any future collaborator.

GH001 is designed to deliver 5-MeO-DMT to the patient via inhalation of an aerosol into the lungs. This aerosol is defined by specific properties to be pharmaceutically acceptable, such as its purity, and to achieve efficient uptake of 5-MeO-DMT into the systemic circulation, such as its particle size distribution. The generation of this 5-MeO-DMT aerosol requires a drug product and a device with specific performance characteristics and properties and it is therefore anticipated that GH001 and the specific device will be considered a drug-device combination product by the FDA, EMA or other comparable foreign regulatory authorities. Products that are considered to be drug-device combination products will require review and coordination by the drug and device centers within the FDA, EMA or other comparable foreign regulatory authorities prior to initiation of clinical trials and prior to marketing approval, which may delay such trials or marketing approval. Under FDA regulations, combination products are subject to current good manufacturing practice, or cGMP, requirements applicable to both drugs and medical devices, including the Quality System, or QS, and regulations applicable to medical devices. Combination products are also subject to the Medical Device Directives and Standards in Europe, which, beginning on May 26, 2021, will be known as the Medical Device Regulation 2017/745, or MDR, and which require coordination between the drug and the device regulatory laws and regulators. Problems associated with the drug product or device component of the combination product candidate may delay or prevent initiation of clinical trials or marketing approval. In current and previous clinical trials, GH001 has been vaporized using a device we purchased on the market from a single third party manufacturer, Storz & Bickel, Tuttlingen. We do not have a commercial supply agreement with this third party, nor have we established licensing or development agreements with any alternative provider of a device which would be suitable to generate a pharmaceutically acceptable aerosol from GH001. If the FDA, EMA or other comparable foreign regulatory authorities refuse to accept the use of this third-party device in our planned clinical trials then initiation of additional clinical trials could be significantly delayed or prevented. If we fail to develop, manufacture, license, or acquire an alternative device which would be suitable to generate a pharmaceutically acceptable aerosol from GH001, which achieves sufficient uptake of 5-MeO-DMT into the systemic circulation, or if we fail to get sufficient supplies of this third-party device or any alternative device or if the device is unavailable to us for any reason then initiation of additional clinical trials or receipt of marketing approval could be significantly delayed or prevented. If the manufacturer of the third-party device makes modifications, or if we elect to change a device component or develop our own proprietary device component, e.g., through a development agreement with a contract manufacturing organization, or CMO, or license an alternative device component, we will need to perform validation testing and obtain FDA, EMA or other comparable foreign regulatory approval prior to using the modified or alternative device component. If the FDA, EMA or other comparable foreign regulatory body fails to approve use of those modified or alternative medical devices or take significant enforcement action against the manufacturer, we would not be able to continue or initiate clinical trials, receive marketing approval or we may have to suspend marketing our products in certain jurisdictions.

In addition, of the large number of drugs in development in the biopharmaceutical industry, only a small percentage result in the submission of a marketing application, such as a new drug application, or NDA, to the FDA, EMA or other comparable foreign regulatory authority, and even fewer are approved for commercialization. Furthermore, even if we do receive regulatory approval for GH001 or GH002, including the medical devices required for their administration, for any indication, any such approval may be subject to limitations on the indications or uses or patient populations for which we may market the product. Accordingly, even if we are able to obtain the requisite financing to continue to fund our development programs, we cannot assure that we will successfully develop or commercialize GH001 or GH002 including the medical devices required for their administration, for any indication. Our failure to demonstrate positive results in our clinical trials in any indication for which we are developing GH001 and GH002 could adversely affect our development efforts for GH001 and GH002 in other indications.

To obtain the requisite regulatory approvals to commercialize any product candidates and medical devices required for their administration, we must demonstrate through extensive nonclinical studies and clinical trials that our product candidates are safe and effective in humans. Clinical testing is expensive and can take many years to complete, and its outcome is inherently uncertain. In particular, in the United States where we hope to advance our product development efforts in the future, the general approach for FDA approval of a new drug is dispositive data from two well-controlled, Phase 3 clinical trials of the relevant drug in the relevant patient population, using the relevant device. Phase 3 clinical trials typically involve hundreds of patients, have significant costs and take years to complete. A product candidate can fail at any stage of testing, even after observing promising signs of activity in earlier nonclinical studies or clinical trials. The results of nonclinical studies and early clinical trials of our product candidates may not be predictive of the results of later-stage clinical trials. Clinical trials with smaller sample sizes can be disproportionately influenced by various biases associated with the conduct of small clinical trials, making the clinical trial results less reliable than clinical trials with a larger number of patients. In addition, initial success in clinical trials may not be indicative of results obtained when such trials are completed. There is typically an extremely high rate of attrition from the failure of product candidates proceeding through clinical trials. Product candidates in later stages of clinical trials may fail to show the desired safety and efficacy profile despite having progressed through nonclinical studies and initial clinical trials. A number of companies in the biopharmaceutical industry have suffered significant setbacks in advanced clinical trials due to a lack of efficacy or emergence of unacceptable safety issues, notwithstanding promising results in earlier studies and trials. Also, a number of companies developing drug-device combination products, especially in the area of inhaled delivery of the drug component, have historically suffered significant setbacks due to technical, performance or manufacturing issues of the device component in their combination product. Most product candidates that commence clinical trials are never approved as products and there can be no assurance that any of our future clinical trials will ultimately be successful or support further clinical development of GH001, GH002 or any other product candidates. Product candidates that appear promising in the early phases of development may fail to reach the market for several reasons, including:

In particular, we have relied upon public nonclinical literature containing limited data thus far, and have not conducted our own nonclinical toxicity studies, and nonclinical studies or clinical trials may show that our product candidates have unacceptable side effects or toxicities.

We assess indications for intensity of psychoactive effect using a metric we devised, Peak Experience, or PE. We believe PE may correlate with clinical outcomes, but PE is a subjective metric and can be inherently difficult to evaluate. In addition, differences in trial design between early-stage clinical trials and later-stage clinical trials make it difficult to extrapolate the results of earlier clinical trials to later clinical trials.

Moreover, our completed Phase 1 clinical trial in healthy volunteers and our ongoing Phase 1/2 clinical trial in patients with TRD are open-label studies, where both the patient and investigator know whether the patient is receiving the product candidate or either an existing approved drug or placebo. Most typically, open-label clinical trials test only the product candidate and sometimes do so at different dose levels. Open-label clinical trials are subject to various limitations that may exaggerate any therapeutic effect as patients in open-label clinical trials are aware when they are receiving treatment. For example, prior MDD studies have exhibited a high placebo effect. In addition, open-label clinical trials may be subject to an “investigator bias,” where those assessing and reviewing the psychological and physiological outcomes of the clinical trials are aware of which patients have received treatment and may interpret the information of the treated group more favorably given this knowledge. Therefore, it is possible that positive results observed in open-label trials will not be replicated in later placebo-controlled or active-controlled trials. Additionally, the trial design differences and placebo effects that may be possible in clinical research for the indications we are studying may make it difficult to extrapolate the results of earlier clinical trials to later clinical trials or to interpret the clinical data in any of our trials. Furthermore, even in a placebo-controlled or active-controlled trial, it is possible that patients and/or investigators will be able to discern if the administered dose is our product candidate or a placebo or the active control due to the psychoactive effects of 5-MeO-DMT. Therefore, placebo-controlled or active-controlled trials with our GH001 and GH002 product candidates may be subject to similar limitations as open-label trials. Finally, our clinical trials to date have been short in duration, and our results may not be predictive of long-term safety and efficacy.

The standards that the FDA, EMA and other comparable foreign regulatory authorities use when regulating us require judgment and can change, which makes it difficult to predict with certainty how they will be applied. Although we are initially focusing our efforts on development of small molecule drug products and the medical devices required for delivery of these products, we may pursue development of other products, e.g., biological products, each of which could make us subject to additional regulatory requirements. Any analysis we perform of data from technical development, nonclinical and clinical activities is subject to confirmation and interpretation by regulatory authorities, which could delay, limit or prevent initiation of clinical studies or regulatory approval. Our clinical trials have only been conducted in the Netherlands. The FDA’s acceptance of data from clinical trials outside of the United States is subject to certain conditions. If the FDA or other comparable foreign regulatory authorities do not accept earlier technical, nonclinical or clinical data, we may need to conduct additional technical development, nonclinical studies or clinical trials.

We may also encounter unexpected delays or increased costs due to new government regulations. Examples of such regulations include future legislation or administrative action, or changes in policy by the FDA, EMA or other comparable foreign regulatory authority during the period of product development and regulatory review. It is impossible to predict whether legislative changes will be enacted, or whether regulations, guidance or interpretations of the FDA, EMA or other comparable foreign regulatory authority will be changed, or what the impact of such changes, if any, may be. In particular, in the United States, where we plan to develop our candidates in the future, the FDA may also require a panel of experts, referred to as an Advisory Committee, to deliberate on the adequacy of the safety and efficacy data to support approval. The opinion of the Advisory Committee, although not binding on the FDA, may have a significant impact on our ability to obtain approval of any product candidates that we develop.

Successful completion of clinical trials is a prerequisite to submitting a marketing application to the FDA or other comparable foreign regulatory authorities, for each product candidate and any relevant device required to deliver such product candidate, and, consequently, the ultimate approval and commercial marketing of any product candidates and medical devices. We may experience negative or

inconclusive results, or regulators may be unwilling to accept nonclinical or clinical data obtained in foreign jurisdictions, which may result in our deciding, or our being required by regulators, to conduct additional clinical studies or trials or abandon some or all of our product development programs, which would have a material adverse effect on our business.

Undesirable side effects that could potentially be caused by GH001, GH002 or any future product candidate, such as hypertension, tachycardia, nausea, headache or flashbacks, referred to as the re-experiencing of some of the effects induced by 5-MeO-DMT intake at some point after the drug’s acute effects have worn off, could cause us or regulatory authorities to not initiate, interrupt, delay or halt clinical trials and could result in more restrictive labeling than anticipated, a requirement that we implement a REMS to ensure that the benefits outweigh the risks or the delay or denial of regulatory approval by the FDA, EMA or comparable foreign regulatory authorities. Results of our clinical trials could reveal a high and unacceptable severity and prevalence of side effects or unexpected characteristics, even death. There can be no assurance that serious side effects, including deaths, will not occur even in the controlled setting of a clinical trial. In addition, many compounds that have initially shown promise in clinical or earlier stage testing are later found to cause undesirable or unexpected side effects that prevented further development of the compound. Additionally, the composition of our product candidates or learnings in nonclinical studies or clinical trials may result in contraindications or warnings, including Boxed Warnings, for any product candidates for which we may obtain regulatory approval.

If unacceptable side effects arise in the development of our product candidates, foreign regulatory authorities, or, in the future, the FDA, EMA, the IRBs, DSMBs or independent ethics committees at the institutions in which our trials are conducted could refuse to allow us to initiate, or may suspend or terminate our nonclinical studies or clinical trials, or the FDA, EMA or other comparable foreign regulatory authorities could order us to cease nonclinical studies or clinical trials or deny approval of our product candidates for any or all targeted indications.

Treatment-emergent side effects that are deemed to be drug-related could also affect subject recruitment or the ability of enrolled subjects to complete the trial or result in potential product liability claims. Undesirable side effects in one of our clinical trials for our product candidates in one indication could adversely affect enrollment in clinical trials, regulatory approval and commercialization of our product candidates in other indications. In addition, these side effects may not be appropriately recognized or managed by the treating medical staff. Any of these occurrences may harm our business, financial condition and prospects significantly.

Moreover, clinical trials of our product candidates are conducted in carefully defined sets of healthy volunteers and patients who have agreed to be enrolled in clinical trials. Consequently, it is possible that our clinical trials, or those of any future collaborator, may fail to identify undesirable side effects. Clinical trials by their nature utilize a sample of the potential patient population. With a limited number of patients, rare and severe side effects of our product candidates may only be uncovered with a significantly larger number of patients’ use of the product candidate. If our product candidates, including the medical devices to deliver such product candidates, receive marketing approval and we or others identify undesirable side effects caused by such product candidates (or any other similar products) after such approval, a number of potentially significant negative consequences could result, including:

In addition, patients who participate in our trials may take antidepressants or other medications to treat depression and/or mood disorders, or other medications that may interact with our product candidates, and participation in our clinical trials requires patients to suspend any such existing medication or treatment for the duration of the trial. If a patient chooses to resume his or her existing medications, there is no guarantee such medications will produce the same therapeutic effect, if any, as may have been experienced prior to suspending such medication. Further, the impact of cycling off and/or back on to existing medications could have undesirable side effects or lead to severe mental health trauma. Any such negative reactions of a patient participating in one of our clinical trials may decrease the willingness of patients to participate in our trials, affect the timing or outcome of our clinical trials, product candidate development and approval process, or create negative public perception around our product candidates, which in turn may significantly impact our ability to successfully commercialize our product candidates.

Any of these events could prevent us from achieving or maintaining market acceptance of the affected product candidates, could negatively impact the perception of our other product candidates, could substantially increase the costs of commercializing our product candidates, if approved, and significantly impact our ability to successfully commercialize our product candidates and generate revenues.

We may experience difficulties in patient enrollment in our clinical trials for a variety of reasons. The timely completion of clinical trials in accordance with their protocols depends, among other things, on our ability to enroll a sufficient number of patients who remain in the study until its conclusion.

Patient enrollment is affected by many factors, including:

In addition, our clinical trials will compete with other clinical trials for product candidates that are in the same therapeutic areas as our product candidates, including product candidates studying N-methyl-D-aspartate antagonists, neurosteroids, and other serotonergic psychedelics such psilocybin and N,N-Dimethyltryptamine. This competition will reduce the number and types of patients available to us, because some patients who might have opted to enroll in our trials may instead opt to enroll in a trial being conducted by one of our competitors. Since the number of qualified clinical investigators is limited, we expect to conduct some of our clinical trials at the same clinical trial sites that some of our competitors use, which will reduce the number of patients who are available for our clinical trials in such clinical trial site.

Our inability to enroll a sufficient number of patients for our clinical trials would result in significant delays or might require us to abandon one or more clinical trials altogether. Delays in patient enrollment may result in increased costs, affect the timing or outcome of the planned clinical trials, product candidate development and approval process and jeopardize our ability to seek and obtain the regulatory approval required to commence product sales and generate revenue, which could prevent completion of these trials, adversely affect our ability to advance the development of our product candidates, cause the value of our company to decline and limit our ability to obtain additional financing if needed.

We are also required to register certain clinical trials and post the results of certain completed clinical trials on a government-sponsored database, such as www.ClinicalTrials.gov in the United States and a similar system in the European Union, within certain timeframes. Failure to do so can result in fines, adverse publicity and civil and criminal sanctions.

From time to time, we may publicly disclose preliminary, interim or topline data from our clinical trials, including the data we have disclosed for our current clinical trials. These interim updates are based on a preliminary analysis of then-available data, and the results and related findings and conclusions are subject to change following a more comprehensive review of the data related to the particular study or trial. We also make assumptions, estimations, calculations and conclusions as part of our analyses of data, and we may not have received or had the opportunity to fully and carefully evaluate all data. As a result, the interim or topline results that we report may differ from future results of the same studies, or different conclusions or considerations may qualify such results, once additional data have been received and fully evaluated. This difference may be more pronounced because of the small sample size and short duration of our clinical trials. Interim or topline data also remain subject to audit and verification procedures that may result in the final data being materially different from the preliminary data we previously reported. As a result, interim or topline data should be viewed with caution until the final data are available. In addition, we may report interim analyses of only certain endpoints rather than all endpoints. Interim data from clinical trials that we may complete are subject to the risk that one or more of the clinical outcomes may materially change as patient enrollment continues and more patient data become available. Adverse changes between interim data and final data could significantly harm our business and prospects. Additional disclosure of interim data by us or by our competitors could result in volatility in the price of our ordinary shares.

Further, others, including regulatory agencies, may not accept or agree with our assumptions, estimates, calculations, conclusions or analyses or may interpret or weigh the importance of data differently, which could impact the value of the particular program, the ability to initiate further clinical studies, the approvability or commercialization of the particular product candidate and our company in general. In addition, the information we choose to publicly disclose regarding a particular study or clinical

trial is typically selected from a more extensive amount of available information. You or others may not agree with what we determine is the material or otherwise appropriate information to include in our disclosure, and any information we determine not to disclose may ultimately be deemed significant with respect to future decisions, conclusions, views, activities or otherwise regarding a particular product candidate or our business. If the interim, preliminary or topline data that we report differ from late, final or actual results, or if others, including the FDA, EMA or other comparable foreign regulatory authorities, disagree with the conclusions reached, our ability to initiate further clinical studies or obtain approval for, and commercialize our product candidates may be harmed, which could harm our business, financial condition, results of operations and prospects.

Our estimates of the potential market opportunity for GH001 and GH002 for the treatment of TRD as well as any other product candidates, include several key assumptions based on our industry knowledge, industry publications and third-party research reports. There can be no assurance that any of these assumptions are, or will remain, accurate. If the actual market for GH001 and GH002 for these or other indications, or for any other product candidate we may develop, is smaller than we expect, our revenue, if any, may be limited and it may be more difficult for us to achieve or maintain profitability.

Our research programs may initially show promise in identifying potential product candidates, yet fail to yield product candidates for clinical development or commercialization for a number of reasons, including:

Research programs to identify new product candidates require substantial technical, financial and human resources. If we are unable to identify suitable compounds for nonclinical and clinical development, we will not be able to obtain product revenue in future periods, which likely would result in significant harm to our financial position and adversely impact the market price of our publicly traded ordinary shares.

We may choose to conduct one or more of our clinical trials in the United States, Europe or in other foreign jurisdictions outside of the Netherlands where our trials currently are being conducted for GH001 and GH002. The acceptance of study data from nonclinical studies and clinical trials conducted outside those jurisdictions may be subject to certain conditions for acceptance. For example, in cases where data from foreign clinical trials are intended to serve as the basis for marketing approval in the United States, the FDA will generally not approve the application on the basis of foreign data alone unless (i) the data are applicable to the U.S. population and U.S. medical practice; and (ii) the trials were performed by clinical investigators of recognized competence and pursuant to Good Clinical Practices, or GCP, regulations. Additionally, the FDA’s clinical trial requirements, including sufficient size of patient populations and statistical powering, must be met. Many foreign regulatory bodies, such as the EMA, have similar approval requirements. In addition, such foreign trials would be subject to the applicable local laws of the foreign jurisdictions where the trials are conducted. There can be no assurance that the FDA, EMA or any applicable foreign regulatory authority will accept data from trials conducted outside of the

United States or the applicable jurisdiction. The FDA may not accept our data given the limited sample size in our completed and existing trials. If the FDA, EMA or any applicable foreign regulatory authority does not accept such data, it would result in the need for additional trials, which would be costly and time-consuming and delay aspects of our business plan, and which may result in our product candidates not receiving approval or clearance for commercialization in the applicable jurisdiction.

We do not currently have a Breakthrough Therapy Designation for any of our product candidates, but we may seek a Breakthrough Therapy Designation for any product candidate that we plan to develop in the United States if we believe the qualifying criteria for such a designation can be met. A Breakthrough Therapy is defined as a drug that is intended, alone or in combination with one or more other drugs, to treat a serious or life-threatening disease or condition, and preliminary clinical evidence indicates that the drug may demonstrate substantial improvement over currently approved therapies on one or more clinically significant endpoints, such as substantial treatment effects observed early in clinical development. For drugs that have been designated as Breakthrough Therapies, interaction and communication between the FDA and the sponsor of the trial can help to identify the most efficient path for clinical development while minimizing the number of patients placed in ineffective control regimens.

The FDA has discretion to determine whether the criteria for a Breakthrough Therapy has been met and whether to grant a Breakthrough Therapy Designation to a product candidate. Accordingly, even if we believe a product candidate, we develop meets the criteria for designation as a Breakthrough Therapy, the FDA may disagree and instead determine not to make such designation. In any event, the receipt of Breakthrough Therapy Designation for a product candidate may not result in a faster development process, review or approval compared to drugs considered for approval under conventional FDA procedures and does not assure ultimate approval by the FDA. In addition, even after granting Breakthrough Therapy Designation to our product candidates, the FDA may later decide that the drugs no longer meet the conditions for qualification and withdraw the designation.

We do not currently have Fast Track Designation or acceptance of an accelerated assessment in the EU for any of our product candidates, but we may seek such a designation for the product candidates we plan to develop in the United States and the European Union, if we believe the qualifying criteria for such a designation/ assessment have been met. If a product is intended for the treatment of a serious or life-threatening condition and nonclinical or clinical data demonstrate the potential to address an unmet medical need for this condition, the product sponsor may apply for Fast Track Designation or accelerated assessment. The FDA and the EMA each have broad discretion whether or not to grant this designation, so even if we believe a particular product candidate is eligible for this designation/assessment, we cannot assure that the FDA or EMA would decide to grant it. Even if we do receive Fast Track Designation and or an accelerated assessment, we may not experience a faster development process, review or approval compared to conventional FDA or EMA procedures. The FDA or EMA may withdraw the Fast Track Designation or accelerated assessment, respectively, if either agency believes that the designation or pathway is no longer supported by data from our clinical development program. Many drugs that have received Fast Track Designation and/or accelerated assessment have failed to obtain regulatory approval.

Because we are considering developing GH001 and/or GH002 for indications we believe to be rare, we may elect to pursue orphan designations for our candidates as applicable in the jurisdictions where development activities are planned.

In the United States, under the Orphan Drug Act, the FDA may grant orphan designation to a drug or biologic intended to treat a rare disease or condition, defined as a disease or condition with a patient population of fewer than 200,000 in the United States, or a patient population greater than 200,000 in the United States when there is no reasonable expectation that the cost of developing and making available the drug or biologic in the United States will be recovered from sales in the United States for that drug or biologic. Orphan drug designation must be requested and granted by the FDA before a new NDA is submitted. In the United States, orphan drug designation entitles a party to financial incentives such as tax advantages, and user-fee waivers. After the FDA grants orphan drug designation, it will disclose publicly the generic identity of the drug and its potential orphan use. Orphan drug designation does not convey any advantage in, or shorten the duration of, the regulatory review and approval process. Such a designation may also be revoked by the FDA in certain circumstances, such as if the agency finds that the applicant’s request for designation request omitted material information required under the Orphan Drug Act and its implementing regulations.

If a product that has orphan drug designation subsequently receives the first FDA approval for a particular active ingredient for the disease for which it has such designation, the product is entitled to orphan product exclusivity. This means that the FDA may not approve any other marketing applications for the same drug and the same indication for seven years, except in limited circumstances such as a showing of clinical superiority to the product with orphan exclusivity or if the FDA finds that the holder of the orphan exclusivity has not shown that it can assure the availability of sufficient quantities of the orphan product to meet the needs of patients with the disease or condition for which the drug was designated. Furthermore, the FDA can waive orphan exclusivity if the applicant is unable to manufacture sufficient supply of the product subject to a period of orphan drug marketing exclusivity.

In the European Union, orphan designation might be granted by the EMA for a medicine that (i) is intended for the treatment, prevention or diagnosis of a disease that is life-threatening or chronically debilitating; (ii) with a prevalence in the European Union of not more than five in 10 thousand or it must be unlikely that marketing of the medicine would generate sufficient returns to justify the investment needed for its development; and (iii) no satisfactory method of diagnosis, prevention or treatment of the condition concerned can be authorized, or, if such a method exists, the medicine must be of significant benefit to those affected by the condition.

In the European Union, orphan designation does not convey any advantage in, or shorten the duration of, the regulatory review and approval process. The benefit of orphan designation in the European Union is scientific advice, and extended market exclusivity, or an additional two years on top of the eight years of market exclusivity for an innovative product. Such a designation may also be revoked by the EMA in certain circumstances, such as if the criteria are no longer met, which might for example occur by a competitor product becoming available in the market. Our inability to obtain or maintain such a designation or the benefits associated with orphan drug status, which could adversely affect our ability to achieve or sustain profitability.

Obtaining and maintaining regulatory approval of our product candidates and medical devices required to deliver such product candidates in one jurisdiction does not guarantee that we will be able to obtain or maintain regulatory approval in any other jurisdiction, but a failure or delay in obtaining regulatory approval in one jurisdiction may have a negative effect on the regulatory approval process in others. For example, even if the FDA grants approval of a product candidate and device required to deliver such product candidate, comparable regulatory authorities in other jurisdictions, including Europe, must also approve the manufacturing, marketing and sale of the product candidate and device required to deliver such product candidate in those countries. Approval procedures vary among jurisdictions and can involve requirements and administrative review periods different from those in the United States, including additional nonclinical studies or clinical trials as clinical trials conducted in one jurisdiction may not be accepted by regulatory authorities in other jurisdictions. In many jurisdictions outside the United States, a product candidate and device must also be approved for reimbursement before it can be approved for sale in that jurisdiction. In some cases, the price that we intend to charge for our products is also subject to governmental approval.

Obtaining foreign regulatory approvals and compliance with foreign regulatory requirements could result in significant delays, difficulties and costs for us and could delay or prevent the introduction of our products in certain countries. If we or any partner we work with fail to comply with the regulatory requirements in international markets or fail to receive applicable marketing approvals, our target market will be reduced and our ability to realize the full market potential of our product candidates will be harmed.

Once regulatory approval has been granted, an approved product and its manufacturer and marketer are subject to ongoing review and extensive regulation. We, and any future collaborators, must therefore comply with requirements concerning advertising and promotion for any of our product candidates for which we or they obtain regulatory approval. Promotional communications with respect to prescription drugs are subject to a variety of legal and regulatory restrictions and must be consistent with the information in the product’s approved labeling. Thus, we and any future collaborators will not be able to promote any products we develop for indications or uses for which they are not approved.

In addition, manufacturers of approved products and those manufacturers’ facilities are required to comply with extensive regulatory requirements, including under FDA authorities ensuring that quality control and manufacturing procedures conform to cGMPs, which include requirements relating to quality control and quality assurance as well as the corresponding maintenance of records and documentation and reporting requirements. We, our contract manufacturers, any future collaborators and their contract manufacturers could be subject to periodic unannounced inspections by regulatory authorities to monitor and ensure compliance with cGMPs. Despite our efforts to inspect and verify regulatory compliance, one or more of our third-party manufacturing vendors may be found on regulatory inspection to be not in compliance with cGMP requirements, which may result in shutdown of the third-party vendor or invalidation of drug product lots or processes. In some cases, a product recall may be warranted or required, which would materially affect our ability to supply and market our drug products.

Accordingly, assuming we, or any future collaborators, receive regulatory approval for one or more of our product candidates, we, and any future collaborators, and our and their contract manufacturers will continue to expend time, money and effort in all areas of regulatory compliance, including manufacturing, production, product surveillance and quality control.

If we, or any future collaborators, are not able to comply with post-approval regulatory requirements, we, or any future collaborators, could have the regulatory approvals for our products withdrawn by regulatory authorities and our, or any future collaborators’, ability to market any future products could be limited, which could adversely affect our ability to achieve or sustain profitability. Further, the cost of compliance with post-approval regulations may have a negative effect on our operating results and financial condition.

Changes in regulatory requirements or regulatory guidance or unanticipated events during our nonclinical studies and clinical trials may force us to amend nonclinical studies and clinical trial protocols or the applicable regulatory authority may impose additional nonclinical studies and clinical trial requirements. Amendments or changes to our clinical trial protocols would generally require resubmission to the applicable regulatory authority and IRBs for review and approval, which may adversely impact the cost, timing or successful completion of clinical trials. These decisions may increase costs, and cause us not to meet expected timelines and, correspondingly, our business and financial prospects could be adversely affected. Similarly, amendments to our nonclinical studies may adversely impact the cost, timing or successful completion of those nonclinical studies. If we experience delays completing, or if we terminate, any of our nonclinical studies or clinical trials, or if we are required to conduct additional nonclinical studies or clinical trials, the development pathway, and ultimately the commercial prospects, for our product candidates may be harmed and our ability to generate product revenue from resulting products, if any, will be delayed.

We are exposed to potential product liability and professional indemnity risks that are inherent in the research, development, manufacturing, marketing and use of biopharmaceutical products. Currently, we have no products that have been approved for commercial sale; however, the use of our product candidates and medical devices to deliver such product candidates by us and any collaborators in clinical trials may expose us to liability claims. We will face an even greater risk if product candidates and medical devices to deliver such product candidates are approved by regulatory authorities and introduced commercially. Product liability claims may be brought against us or our partners if any product candidate or medical devices to deliver such product candidates we develop allegedly causes injury or are found to be otherwise unsuitable for human use during product testing, manufacturing, marketing or sale. Any such product liability claim may include allegations of defects in manufacturing, defects in design, a failure to warn of dangers inherent in the product, negligence, strict liability and a breach of warranties. Claims could also be asserted under state consumer protection acts. Such claims could be made by participants enrolled in our clinical trials, patients, healthcare providers, biopharmaceutical companies, our collaborators or others using, administering or selling any of our future approved products. If we cannot successfully defend ourselves against any such claims, we may incur substantial liabilities or be required to limit commercialization of our product candidates. Even successful defense would require significant financial and management resources.

Regardless of the merits or eventual outcome, product liability claims may result in:

Although the clinical trial process is designed to identify and assess potential side effects, clinical development does not always fully characterize the safety and efficacy profile of a new medicine, and it is always possible that a drug, even after regulatory approval, may exhibit unforeseen side effects. If our product candidates were to cause adverse side effects during clinical trials or after approval, we may be exposed to substantial liabilities. Physicians and patients may not comply with any warnings that identify known potential adverse effects and patients who should not use our product candidates. If any of our product candidates are approved for commercial sale, we will be highly dependent upon consumer perceptions of us and the safety and quality of our products. We could be adversely affected if we are subject to negative publicity associated with illness or other adverse effects resulting from physicians’ or patients’ use or misuse of our products or any similar products distributed by other companies.

We maintain product liability insurance coverage limited to clinical trial liability, and this insurance may not fully cover potential liabilities that we may incur. The cost of any product liability litigation or other proceeding, even if resolved in our favor, could be substantial. We will need to increase our insurance coverage if we commercialize any product that receives regulatory approval. In addition, insurance coverage is becoming increasingly expensive. If we are unable to maintain sufficient insurance coverage at an acceptable cost or to otherwise protect against potential product liability claims, it could prevent or inhibit the development and commercial production and sale of our product candidates, which could harm our business, financial condition, results of operations and prospects.

The development and commercialization of new drug products is highly competitive. We may face competition with respect to any product candidates that we seek to develop or commercialize from biopharmaceutical companies worldwide. Potential competitors also include academic institutions, government agencies, and other public and private research organizations that conduct research, seek patent protection, and establish collaborative arrangements for research, development, manufacturing and commercialization.

Specifically, we face competition from 501(c)(3) non-profit medical research organizations, including the Usona Institute. Such non-profits may be willing to provide treatment at cost or for free, undermining our potential market for GH001, GH002 and any other product candidates we may develop. In addition, a number of for-profit biotechnology companies or institutions are specifically pursuing the development of

5-MeO-DMT or other tryptamines, such as psilocybin and N,N-Dimethyltryptamine, to treat mental health illnesses, including TRD. These competitors include Beckley Psytech, COMPASS Pathways, Cybin, Entheon, Mindmed, Small Pharma, and Viridia Life Sciences. In addition, an increasing number of companies are stepping up their efforts in discovery of new psychoactive compounds. It is also probable that the number of companies seeking to develop psychoactive products and therapies for the treatment of mental health illnesses, such as depression, will increase. If any of our competitors are granted an NDA for their therapies before us and manages to obtain approval for a broader indication, and thus access a wider patient population, we may face more intensified competition from such potential therapies and increased difficulties in winning market acceptance of our GH001 and GH002 product candidates or any future product candidates. All of these risks are heightened because 5-MeO-DMT, which is a naturally occurring substance and therefore not subject to patent protection, may be deemed an appropriate substitute for GH001 and GH002.

We also face competition from larger and smaller pharmaceutical, biopharmaceutical and biotechnology companies who have developed or are developing therapies for the treatment of MDD and TRD, including Axsome Therapeutics, Praxis Precision Medicines, Relmada Therapeutics and Sage Therapeutics, and will face future competition for any other indications we may seek to treat with our GH001 and GH002 product candidates. There are a number of companies that currently market and sell products or therapies, or are pursuing the development of products or therapies, for the treatment of depression, including antidepressants such as SSRIs and serotonergic norepinephrine reuptake inhibitors, or SNRIs, antipsychotics, cognitive behavioral therapy, or CBT, esketamine and ketamine, repeat transcranial magnetic stimulation, or rTMS, electroconvulsive therapy, or ECT, vagus nerve stimulation, or VNS, deep brain stimulation, or DBS, N-methyl-D-aspartate antagonists, neurosteroids, and other serotonergic psychedelics such as psilocybin and N,N-Dimethyltryptamine, among others. Many of these pharmaceutical, biopharmaceutical and biotechnology competitors have established markets for their therapies and have substantially greater financial, technical, human and other resources than we do and may be better equipped to develop, manufacture and market superior products or therapies. In addition, many of these competitors have significantly greater experience than we have in undertaking nonclinical studies and human clinical trials of new therapeutic substances and in obtaining regulatory approvals of human therapeutic products. Accordingly, our competitors may succeed in obtaining FDA, EMA or other comparable foreign regulatory authority approval for alternative or superior products. In addition, many competitors have greater name recognition and more extensive collaborative relationships. Smaller and earlier-stage companies may also prove to be significant competitors, particularly through collaborative arrangements with large, established companies.

If any of these competitors or competitors for our other product candidates receive FDA, EMA or other comparable foreign regulatory authority approval before we do, our product candidates would not be the first treatment on the market, and our market share may be limited. In addition to competition from other companies targeting our target indications, any products we may develop may also face competition from other types of therapies.

Many of our current or potential competitors, either alone or with their strategic partners, have:

Mergers and acquisitions in the biopharmaceutical industry may result in even more resources being concentrated among a smaller number of our competitors. Smaller or early-stage companies may also

prove to be significant competitors, particularly through collaborative arrangements with large and established companies. These competitors also compete with us in recruiting and retaining qualified scientific and management personnel and establishing clinical trial sites and patient registration for clinical trials, as well as in acquiring technologies complementary to, or necessary for, our programs. Our commercial opportunity could be reduced or eliminated if our competitors develop and commercialize products that are safer, more effective, have fewer or less severe side effects, are more convenient or are less expensive than any products that we may develop. Furthermore, currently approved products could be discovered to have application for treatment of our targeted disease indications or similar indications, which could give such products significant regulatory and market timing advantages over our product candidates. Our competitors also may obtain FDA, EMA or other comparable foreign regulatory approval for their products more rapidly than we may obtain approval for ours and may obtain orphan product exclusivity from the FDA for indications that we are targeting, which could result in our competitors establishing a strong market position before we are able to enter the market. Additionally, products or technologies developed by our competitors may render our potential product candidates uneconomical or obsolete and we may not be successful in marketing any product candidates we may develop against competitors.

In addition, we could face litigation or other proceedings with respect to the scope, ownership, validity and/or enforceability of our patents relating to our competitors’ products and our competitors may allege that our products infringe, misappropriate or otherwise violate their intellectual property. The availability of our competitors’ products could limit the demand, and the price we are able to charge, for any products that we may develop and commercialize.

In current and previous clinical trials, GH001 has been vaporized using a device we have purchased on the market from a third party. This device has been used in previous trials in the United States. However, there can be no assurance that the FDA or other comparable foreign regulatory authorities will allow it to be used with GH001. In addition, we may decide in future clinical trials to use a different device than the one we have used previously. In either case, we would need to do additional development work and conduct additional studies, including bridging studies to bridge our prior device to any new device we may decide to use, prior to using the new device in future clinical trials. Any delays as a result of changing medical devices to deliver our product candidates would have a material adverse effect on our business.

We do not have a commercial supply agreement with the third-party manufacturer of the device we currently use in clinical trials, nor have we established license or development agreements with any alternative provider of a device, which would be suitable to generate a pharmaceutically acceptable aerosol from GH001. If FDA, EMA or other comparable foreign regulatory authorities refuse to accept the use of the current third-party device in our planned clinical trials and if we fail to develop, manufacture, license, or acquire an alternative device which would be suitable to generate a pharmaceutically acceptable aerosol from GH001, or if we fail to get sufficient supplies of the current third-party device or any alternative device, then initiation of additional clinical trials or marketing approval could be significantly delayed or prevented.

GH001 is administered via inhalation of an aerosol produced by a vaporization device. This device is necessary to produce the aerosol and it is therefore a drug and device combination product that requires coordination within the FDA or other comparable foreign regulatory authorities for review of their device and drug components. Medical products containing a combination of new drugs, biological products or medical devices may be regulated as “combination products” in the United States and Europe. A combination product generally is defined as a product comprised of components from two or more

regulatory categories (e.g., drug/device, device/biologic, drug/biologic). Each component of a combination product is subject to the requirements established by the FDA for that type of component, whether a new drug, biologic or device. In order to facilitate pre-market review of combination products, the FDA designates one of its centers to have primary jurisdiction for the pre-market review and regulation of the overall product based upon a determination by the FDA of the primary mode of action of the combination product. Where approval of the drug and device is sought under a single application, there could be delays in the approval process due to the increased complexity of the review process. The EMA has a parallel review process in place for combination products, the potential effects of which in terms of approval and timing could independently affect our ability to market our combination products in Europe.

In the United States, 5-MeO-DMT is listed by the DEA as a controlled substance or scheduled substance, under the CSA, specifically as a Schedule I substance. The DEA regulates chemical compounds as Schedule I, II, III, IV or V substances. Schedule I substances by definition have a high potential for abuse, have no currently “accepted medical use” in the United States, lack accepted safety for use under medical supervision, and may not be prescribed, marketed or sold in the United States. Pharmaceutical products approved for medical use in the United States may be listed as Schedule II, III, IV or V, with Schedule II substances considered to present the highest potential for abuse or dependence and Schedule V substances the lowest relative risk of abuse among such substances. Schedule I and II drugs are subject to the strictest controls under the CSA, including manufacturing and procurement quotas, security requirements and import/export restrictions. In addition, dispensing of Schedule II drugs is further restricted. For example, they may not be refilled without a new prescription and may have a black box warning. Further, most, if not all, state laws in the United States classify 5-MeO-DMT as a Schedule I controlled substance. For any product containing 5-MeO-DMT to be available for commercial marketing in the United States, 5-MeO-DMT must be rescheduled to Schedule II, III, IV or V, or the DEA must reschedule a specific dosage form or product containing 5-MeO-DMT to Schedule II, III, IV or V. Similar rescheduling would be required in the various states and jurisdictions through scheduling-related legislative or administrative action.

Scheduling determinations by the DEA are dependent on FDA approval of a substance or a specific formulation of a substance. Therefore, while 5-MeO-DMT is a Schedule I controlled substance, products approved by the FDA for medical use in the United States that contain 5-MeO-DMT would meet the statutory criteria to be placed in Schedule II, or another schedule, since approval by the FDA satisfies the “accepted medical use” requirement. If and when GH001 or GH002 receives FDA approval, the DEA will need to make a scheduling determination and place 5-MeO-DMT in a schedule other than Schedule I in order for it to be prescribed to patients in the United States. This scheduling determination will be dependent on FDA approval and the FDA’s recommendation as to the appropriate schedule. During the review process, and prior to approval, the FDA may determine that it requires additional data, either from nonclinical or clinical studies, including with respect to whether, or to what extent, the substance has the potential for abuse. This may introduce a delay into the approval and any potential rescheduling process. That delay would be dependent on the quantity of additional data required by the FDA. This scheduling determination will require the DEA to conduct notice and comment rulemaking. Such action will be subject to public comment and requests for an administrative hearing which could affect the timing and scheduling of these substances.

If approved by the FDA, and if the finished dosage form of GH001 or GH002 is listed by the DEA as a Schedule II, III, or IV controlled substance, its manufacture, importation, exportation, domestic distribution, storage, sale, prescribing, and dispensing will continue to be subject to a significant degree of regulation by the DEA. In addition, the scheduling process may take significantly longer than the 90-day deadline set forth in the CSA, thereby delaying the launch of our GH001 or GH002 product candidates in the United States. Furthermore, the FDA, DEA, or any comparable foreign regulatory authority could require us to generate more clinical or other data than we currently anticipate to establish whether or to what extent the substance has an abuse potential, which could increase the cost and/or delay the launch of GH001, GH002 and any future product candidates containing controlled substances. In addition, product candidates containing controlled substances are subject to regulations relating to manufacturing, storage, distribution, prescribing, and dispensing, including:

If 5-MeO-DMT, rather than just a specific FDA-approved formulation, is rescheduled under the CSA as a Schedule II or lower controlled substance (i.e., Schedule III, IV or V), the ability to conduct research on 5-MeO-DMT would most likely be improved. However, rescheduling 5-MeO-DMT may materially alter enforcement policies across many federal and state agencies, primarily the FDA and DEA. The FDA is responsible for ensuring public health and safety through regulation of food, drugs, supplements, and cosmetics, among other products, through its enforcement authority pursuant to the Federal Food, Drug, and Cosmetic Act, or FDCA. The FDA’s responsibilities include regulating the ingredients as well as the marketing and labeling of drugs sold in interstate commerce. Because it is currently illegal under federal law to produce and sell 5-MeO-DMT, and because there are no federally recognized medical uses, the FDA has historically deferred enforcement related to 5-MeO-DMT to the DEA. If 5-MeO-DMT were to be rescheduled to a federally controlled, yet legal, substance, the FDA would likely play a more active regulatory role. The DEA would continue to be active in regulating manufacturing, distribution and dispensing of such substances. The potential for multi-agency enforcement post-rescheduling, including state agencies, e.g., Boards of Pharmacy, could threaten or have a materially adverse effect on our business.

Therapies containing controlled substances may generate public controversy. Political and social pressures and adverse publicity could lead to delays in approval of, and increased expenses for, GH001, GH002 and any future product candidates we may develop. Opponents of these therapies may seek restrictions on marketing and withdrawal of any regulatory approvals. In addition, these opponents may seek to generate negative publicity in an effort to persuade the medical community to reject these therapies. For example, we may face media-communicated criticism directed at our clinical development program. Adverse publicity from 5-MeO-DMT misuse may adversely affect the commercial success or market penetration achievable by our GH001 and GH002 product candidates. Anti-psychedelic protests have historically occurred and may occur and generate media coverage. Political pressures and adverse publicity could lead to delays in, and increased expenses for, and limit or restrict the introduction and marketing of, GH001, GH002 or any future product candidates.

If GH001, GH002 or any future product candidates are approved for commercial sale, we will be highly dependent upon consumer perceptions of the safety and quality of our therapies. We may face limited adoption if third-party therapy sites, therapists, and patients are unwilling to try such a novel treatment. Even if therapies containing controlled substances become widely accepted by physicians and patients, our success will depend in large part on our ability to educate and train physicians and patients, and to successfully demonstrate the safety, tolerability, ease of use, efficacy, cost effectiveness and other advantages of therapies containing controlled substances. There has been a history of negative media coverage regarding psychedelic substances, including 5-MeO-DMT, which may affect the public’s perception of our therapies. In addition, 5-MeO-DMT elicits intense psychological experiences, and this could deter patients from choosing this course of treatment. We could be adversely affected if we were subject to negative publicity or if any of our therapies or any similar therapies distributed by other companies prove to be, or are asserted to be, harmful to patients. Because of our dependence upon consumer perception, any adverse publicity associated with illness or other adverse effects resulting from patients’ use or misuse of our therapies or any similar therapies distributed by other companies could have a material adverse impact on our business, prospects, financial condition and results of operations.

Future adverse events in research into depression and mental health diseases on which we focus our research efforts, or the pharmaceutical industry more generally, could also result in greater governmental regulation, stricter labeling requirements and potential regulatory delays in the testing or approvals of our therapies. Any increased scrutiny could delay or increase the costs of obtaining regulatory approval for GH001, GH002 or any future product candidates.

5-MeO-DMT is categorized as a Schedule I controlled substance under the CSA, a Schedule 1 drug under the United Kingdom’s Misuse of Drugs Regulations 2001 and is similarly categorized by most states, foreign governments and the UN Convention on Psychotropic Substances, 1971. Even assuming that GH001, GH002 or any future product candidates containing 5-MeO-DMT in specific formulations or dosage forms are approved and scheduled by regulatory authorities to allow their commercial marketing, the ingredients in such product candidates would likely continue to be Schedule I, or the state or foreign equivalent. Violations of any federal, state or foreign laws and regulations could result in significant fines, penalties, administrative sanctions, convictions or settlements arising from civil proceedings conducted by either the federal government or private citizens, or criminal charges and penalties, including, but not limited to, disgorgement of profits, cessation of business activities, divestiture, or prison time. This would have a material adverse effect on us, including on our reputation and ability to conduct business, the potential listing of our ordinary shares, our financial position, operating results, profitability or liquidity or the market price of our ordinary shares. In addition, it is difficult for us to estimate the time or resources that would be needed for the investigation or defense of any such matters or our final resolution because, in part, the time and resources that may be needed are dependent on the nature and extent of any information requested by the applicable authorities involved, and such time or resources could be substantial. It is also illegal to aid or abet such activities or to conspire or attempt to engage in such activities. An investor’s contribution to and involvement in such activities may result in federal civil and/or criminal prosecution, including, but not limited to, forfeiture of his, her or its entire investment, fines and/or imprisonment.

Various federal, state, provincial and local laws govern our business in the jurisdictions in which we operate or currently plan to operate, and to which we export or currently plan to export our products, including laws relating to health and safety, the conduct of our operations, and the production, storage, sale and distribution of our products. Complying with these laws requires that we comply concurrently with complex federal, state, provincial and/or local laws. These laws change frequently and may be difficult to interpret and apply. To ensure our compliance with these laws, we will need to invest significant financial and managerial resources. It is impossible for us to predict the cost of such laws or the effect they may have on our future operations. A failure to comply with these laws could negatively affect our business and harm our reputation. Changes to these laws could negatively affect our competitive position and the markets in which we operate, and there is no assurance that various levels of government in the jurisdictions in which we operate will not pass legislation or regulation that adversely impacts our business.

In addition, even if we or third parties were to conduct activities in compliance with U.S. state or local laws or the laws of other countries and regions in which we conduct activities, potential enforcement proceedings could involve significant restrictions being imposed upon us or third parties, while diverting the attention of key executives. Such proceedings could have a material adverse effect on our business, revenue, operating results and financial condition as well as on our reputation and prospects, even if such proceedings conclude successfully in our favor. In the extreme case, such proceedings could ultimately involve the criminal prosecution of our key executives, the seizure of corporate assets, and consequently, our inability to continue business operations. Strict compliance with state and local laws with respect to

5-MeO-DMT does not absolve us of potential liability under U.S. federal law, the laws of EU member states or of the United Kingdom, nor provide a defense to any proceeding which may be brought against us. Any such proceedings brought against us may adversely affect our operations and financial performance.

Despite the current status of 5-MeO-DMT as a Schedule I controlled substance in the United States, there may be changes in the status of 5-MeO-DMT under the laws of certain U.S. cities or states. The legalization of 5-MeO-DMT without regulatory oversight may lead to the setup of clinics without proper therapeutic infrastructure or adequate clinical research, which could put patients at risk and bring reputational and regulatory risk to the entire industry, making it harder for us to achieve regulatory approval. Furthermore, the legalization of 5-MeO-DMT could also impact our commercial sales if we receive regulatory approval as it would reduce the barrier to entry and could increase competition.

Even if the FDA or a comparable foreign regulatory authority approves any of our product candidates and the medical devices required to deliver such product candidates, we will be subject to ongoing regulatory requirements in the applicable jurisdictions for manufacturing, labeling, packaging, storage, advertising, promotion, sampling, record keeping, conduct of post-marketing studies and submission of safety, efficacy and other post-market information. In addition, we will be subject to continued compliance with cGMP and GCP requirements for any clinical trials that we conduct post-approval.

Manufacturers and their facilities are required to comply with extensive regulatory authority requirements, including ensuring that quality control and manufacturing procedures conform to cGMP regulations. As such, we and our contract manufacturers will be subject to continual review and inspections to assess compliance with cGMP and adherence to commitments made in any marketing application, and previous responses to inspection observations. Accordingly, we and others with whom we work must continue to expend time, money, and effort in all areas of regulatory compliance, including manufacturing, production and quality control.

Any regulatory approvals that we receive for our product candidates and the medical devices required to deliver such product candidates may be subject to limitations on the approved indicated uses for which the product may be marketed or to the conditions of approval, or contain requirements for potentially costly post-marketing testing, including Phase 4 clinical trials and surveillance to monitor the safety and efficacy of the product candidate. In the United States, the FDA may also require a REMS as a condition of approval of our product candidates, which could entail requirements for long-term patient follow-up, a medication guide, physician communication plans or additional elements to ensure safe use, such as restricted distribution methods, patient registries and other risk minimization tools. In addition, if the FDA or a comparable foreign regulatory authority approves our product candidates, we will have to comply with requirements including submissions of safety and other post-marketing information and reports and registration.

In the United States, the FDA may withdraw approval if compliance with regulatory requirements and standards is not maintained or if problems occur after the product reaches the market. Later discovery of previously unknown problems with our product candidates, including adverse events of unanticipated severity or frequency, or with our third-party manufacturers or manufacturing processes, or failure to comply with regulatory requirements, may result in revisions to the approved labeling to add new safety information or other restrictions; imposition of post-market studies or clinical trials to assess new safety risks; or imposition of distribution restrictions or other restrictions under a REMS. Other potential consequences include, among other things:

Regulatory authorities strictly regulate marketing, labeling, advertising and promotion of products that are placed on the market. Products may be promoted only for the approved indications and in accordance with the provisions of the approved label. However, in the United States, companies may share truthful and not misleading information that is not inconsistent with the labeling. The FDA and other comparable foreign regulatory authorities actively enforce the laws and regulations prohibiting the promotion of off-label uses and a company that is found to have improperly promoted off-label uses may be subject to significant liability. Violations of the FDCA relating to the promotion of prescription drugs may also lead to investigations alleging violations of federal and state healthcare fraud and abuse laws, as well as state consumer protection laws. Accordingly, to the extent we receive marketing approval for one or more of our product candidates, we and our third-party partners will continue to expend time, money and effort in all areas of regulatory compliance, including promotional and labeling compliance, manufacturing, production, product surveillance and quality control.

The policies of the FDA or other comparable foreign regulatory authorities may change and additional government regulations may be enacted that could prevent, limit or delay regulatory approval of our product candidates. We cannot predict the likelihood, nature or extent of government regulation that may arise from future legislation or administrative action, either in the United States or abroad. If we are slow to, or unable to adapt to changes in existing requirements or the adoption of new requirements or policies, or if we are not able to maintain regulatory compliance, we may lose any marketing approval that we may have obtained and we may not achieve or sustain profitability.

Even if any of the product candidates we develop receives marketing approval, they may nonetheless fail to gain sufficient market acceptance by physicians, patients, third-party payors, such as Medicare and Medicaid programs and managed care organizations in the United States, and others in the medical community. In addition, the availability of coverage by third-party payors may be affected by existing and future healthcare reform measures designed to reduce the cost of health care. If the product

candidates we develop do not achieve an adequate level of acceptance, we may not generate significant product revenues and we may not become profitable.

The degree of market acceptance of any product candidate, if approved for commercial sale, will depend on a number of factors, including:

If government and other third-party payors do not provide coverage and adequate reimbursement levels for any products we commercialize, market acceptance and commercial success would be reduced.

Significant uncertainty exists as to the coverage and reimbursement status of any products for which we may obtain regulatory approval. In the United States and in other countries, patients who are provided medical treatment for their conditions generally rely on third-party payors to reimburse all or part of the costs associated with their treatment. The availability of coverage and adequacy of reimbursement for our products by third-party payors, including government healthcare programs (e.g., Medicare, Medicaid, TRICARE), managed care providers, private health insurers, health maintenance organizations and other organizations is essential for most patients to be able to afford medical services and biopharmaceutical products such as our product candidates. Third-party payors decide which medications they will pay for and establish reimbursement levels.

In the United States, the principal decisions about reimbursement for new medicines are typically made by the Centers for Medicare & Medicaid Services, or CMS, an agency within the U.S. Department of Health and Human Services, or HHS. CMS decides whether and to what extent our products will be covered and reimbursed under Medicare and private payors tend to follow CMS to a substantial degree. Factors payors consider in determining reimbursement are based on whether the product is:

Our ability to successfully commercialize our product candidates will depend in part on the extent to which coverage and adequate reimbursement for our products and related treatments will be available from third-party payors. Moreover, a payor’s decision to provide coverage for a product does not imply that an adequate reimbursement rate will be approved. If coverage and adequate reimbursement is not available, or is available only to limited levels, we may not be able to successfully commercialize our product candidates. Even if coverage is provided, the approved reimbursement amount may not be high enough to allow us to establish or maintain pricing sufficient to realize a sufficient return on our investment.

In the United States, no uniform policy for coverage and reimbursement for products exists among third-party payors. Therefore, coverage and reimbursement for our products can differ significantly from payor to payor. The process for determining whether a payor will provide coverage for a product may be separate from the process for setting the reimbursement rate that the payor will pay for the product. One payor’s determination to provide coverage for a product does not assure that other payors will also provide coverage and reimbursement for the product. Third-party payors may also limit coverage to specific products on an approved list, or formulary, which might not include all of the FDA-approved products for a particular indication. We cannot be sure that coverage and reimbursement will be available for, or accurately estimate the potential revenue from, our product candidates.

A decision by a third-party payor not to cover or not to separately reimburse for our medical products or therapies using our products could reduce physician utilization of our products once approved. Assuming there is coverage for our product candidates, or therapies using our product candidates by a third-party payor, the resulting reimbursement payment rates may not be adequate or may require co-payments that patients find unacceptably high. We cannot be sure that coverage and reimbursement in the United States will be available for our current or future product candidates, or for any procedures using such product candidates, and any reimbursement that may become available may not be adequate or may be decreased or eliminated in the future.

Further, increasing efforts by third-party payors in the United States and abroad to cap or reduce healthcare costs may cause such organizations to limit both coverage and the level of reimbursement for newly approved products and, as a result, they may not cover or provide adequate payment for our product candidates. In order to secure coverage and reimbursement for any product that might be approved for sale, we may need to conduct expensive pharmacoeconomic studies in order to demonstrate the medical necessity and cost effectiveness of our products, in addition to the costs required to obtain FDA, EMA or other comparable foreign regulatory approvals. Additionally, we may also need to provide discounts to purchasers, private health plans or government healthcare programs. Our product candidates may nonetheless not be considered medically necessary or cost-effective. If third-party payors do not consider a product to be cost-effective compared to other available therapies, they may not cover the product after approval as a benefit under their plans or, if they do, the level of payment may not be sufficient to allow a company to sell its products at a profit. We expect to experience pricing pressures from third-party payors in connection with the potential sale of any of our product candidates.

Our commercial success with GH001, GH002 or any future product candidates, if approved, will be dependent upon our ability to identify, qualify, prepare, certify, and support third-party clinics or treatment centers that administer our product candidates. We expect that GH001, GH002 and any future product candidates will be administered in qualified third-party clinics or treatment centers by certified healthcare providers. Because we intend to work with third-party centers and providers who agree to adhere to our treatment protocols, possibly under an FDA REMS or a Risk Management Program, or RMP, in Europe with restricted distribution methods, we may face limitations on the number of sites available to administer GH001, GH002 or future product candidates. Moreover, sites may have difficulty satisfying the requirements of any REMS or RMP. Any limitations on the sites available to administer GH001, GH002 or future product candidates could make it impracticable or impossible for some potential patients to access our product candidates, if approved, which could limit the overall size of our potential patient population and harm our future results of operations.

If we are unable to establish or collaborate with a sufficient network of third-party clinics or treatment centers certified under applicable standards, including regional, national, state or other applicable standards as needed to administer GH001, GH002 or any future product candidate, including the certifications that such third-party clinics or treatment centers may require under a potential REMS in the United States or RMP in Europe, it would have a material adverse effect on our business and ability to grow and would adversely affect our results of operations and commercialization efforts.

Given the novel nature and scheduled drug aspect of our treatment, third-party clinics or treatment centers may face additional financial and administrative burdens in order to deliver any approved therapy, including adhering to a REMS in the United States or an RMP in Europe. The process for a third-party clinic or treatment center to comply with a REMS can be costly and time-consuming, which could delay a third-party clinic or treatment centers’ ability to administer our product candidates and materially adversely affect our commercialization trajectory. Furthermore, third-party clinics or treatment centers will need to ensure that they have the necessary infrastructure and equipment in order to deliver GH001, GH002 or any future product candidates, such as adequate ancillary equipment and sufficient treatment rooms. This may deter third-party clinics or treatment centers from providing GH001, GH002 or any future product candidates and reduce our ability to expand our network and generate revenue.

In some foreign countries, the proposed pricing for a drug must be approved before it may be lawfully marketed. Some countries have a separate decision-making process in addition to whether the government or state insurers will reimburse the price for the product. The requirements governing drug pricing vary widely from country to country. For example, in the European Union, member states can restrict the range of medicinal products for which their national health insurance systems provide reimbursement and they can control the prices of medicinal products for human use. To obtain reimbursement or pricing approval, some of these countries may require the completion of clinical trials that compare the cost effectiveness of a particular product candidate to currently available therapies. A member state may approve a specific price for the medicinal product. In the United Kingdom, it instead adopts a system of direct or indirect controls on the profitability of the innovator company placing the medicinal product on the market. Approaches between member states are diverging. For example, in France, effective market access will be supported by agreements with hospitals and products may be reimbursed by the Social Security Fund. The price of medicines is negotiated with the Economic Committee for Health Products, or CEPS. There can be no assurance that any country that has price controls or reimbursement limitations for biopharmaceutical products will allow favorable reimbursement

and pricing arrangements for any of our product candidates. Historically, products launched in the European Union do not follow price structures of the United States and generally prices tend to be significantly lower and may be insufficient to generate commercially reasonable revenues and profits.

In order to market any products in the United States or European Union, we must establish and comply with numerous and varying regulatory requirements regarding safety and efficacy. Clinical trials conducted in one country may not be accepted by regulatory authorities in other countries, and regulatory approval in one country does not mean that regulatory approval will be obtained in any other country. Approval procedures vary among countries and can involve additional product testing and validation and additional administrative review periods. Seeking foreign regulatory approvals outside of where our clinical trials currently have been conducted could result in significant delays, difficulties and costs for us and may require additional nonclinical studies or clinical trials which would be costly and time consuming. Regulatory requirements can vary widely from country to country and could delay or prevent the introduction of our products in those countries. Satisfying these and other regulatory requirements is costly, time consuming, uncertain and subject to unanticipated delays. In addition, our failure to obtain regulatory approval in any country may delay or have negative effects on the process for regulatory approval in other countries. We do not have any product candidates approved for sale in any jurisdiction, including international markets, and we do not have experience in obtaining regulatory approval in international markets. If we fail to comply with regulatory requirements in international markets or to obtain and maintain required approvals, our ability to realize the full market potential of our products will be harmed.

We have no internal sales, marketing or distribution capabilities, nor have we commercialized a product. If any of our product candidates ultimately receives regulatory approval, we expect to establish a marketing and sales organization with technical expertise and supporting distribution capabilities to commercialize each such product in major markets, which will be expensive and time consuming. We have no prior experience as a company in the marketing, sale and distribution of biopharmaceutical products and there are significant risks involved in building and managing a sales organization, including our ability to hire, retain and incentivize qualified individuals, generate sufficient sales leads, provide adequate training to sales and marketing personnel and effectively manage a geographically dispersed sales and marketing team. Any failure or delay in the development of our internal sales, marketing and distribution capabilities would adversely impact the commercialization of these products. We may also choose to collaborate with third parties that have direct sales forces and established distribution systems, either to augment our own sales force and distribution systems or in lieu of our own sales force and distribution systems. We may not be able to enter into collaborations or hire consultants or external service providers to assist us in sales, marketing and distribution functions on acceptable financial terms, or at all. In addition, our product revenues and our profitability, if any, may be lower if we rely on third parties for these functions than if we were to market, sell and distribute any products that we develop ourselves. We likely will have little control over such third parties, and any of them may fail to devote the necessary resources and attention to sell and market our products effectively. If we are not successful in commercializing our products, either on our own or through arrangements with one or more third parties, we may not be able to generate any future product revenue and we would incur significant additional losses.

We plan to conduct business globally and may file income tax returns in multiple jurisdictions in the future. Our consolidated effective income tax rate could be materially adversely affected by several factors, including: changing tax laws, regulations and treaties, or the interpretation thereof; tax policy initiatives and reforms under consideration (such as those related to the Organization for Economic Co-Operation and Development’s, or OECD, Base Erosion and Profit Shifting, or BEPS, Project, the OECD’s Pillar One and Pillar Two initiatives and other initiatives); the practices of tax authorities in jurisdictions in which we operate; the resolution of issues arising from tax audits or examinations and any related interest or penalties. Such changes may include (but are not limited to) the taxation of operating income, investment income, dividends received or (in the specific context of withholding tax) dividends paid.

We are unable to predict what tax reform may be proposed or enacted in the future or what effect such changes would have on our business, but such changes, to the extent they are brought into tax legislation, regulations, policies or practices in jurisdictions in which we operate, could increase the estimated tax liability that we have expensed to date and paid or accrued on our balance sheets, and otherwise affect our financial position, future results of operations, cash flows in a particular period and overall our effective tax rates in the future in countries where we have operations, reduce post-tax returns to our shareholders and increase the complexity, burden and cost of tax compliance.

A tax authority may disagree with tax positions that we have taken or will take, which could result in increased tax liabilities. For example, The Office of the Revenue Commissioners of Ireland, or Revenue, or another tax authority could challenge our potential future allocation of income by tax jurisdiction and the amounts paid between potential future affiliated companies pursuant to potential future intercompany arrangements and transfer pricing policies, including amounts to be paid with respect to our intellectual property development. Similarly, a tax authority could assert that we are subject to tax in a jurisdiction where we believe we have not established a taxable connection, often referred to as a “permanent establishment” under international tax treaties, and such an assertion, if successful, could increase our expected tax liability in one or more jurisdictions. Additionally, a tax authority could assert that we are tax resident in a jurisdiction where we believe we are not. A change of tax residency could subject us to a higher tax rate or an exit tax.

A tax authority may take the position that material tax liabilities, interest and penalties are payable by us, for example where there has been a technical violation of contradictory laws and regulations that are relatively new and have not been subject to extensive review or interpretation, in which case we expect that we might contest such assessment. High-profile companies can be particularly vulnerable to aggressive application of unclear requirements. Many companies must negotiate their tax bills with tax inspectors who may demand higher taxes than applicable law appears to provide. Contesting such an assessment may be lengthy and costly and if we were unsuccessful in disputing the assessment, the implications could increase our anticipated effective tax rate, where applicable.

We exercise significant judgment when determining tax filing positions. The tax rules and regulations are very complex and there can be no assurance that management’s interpretation and application of these rules and regulations to determine tax filing positions will be accepted by the tax authorities. If the tax authorities reject a tax filing position taken by the Company, it could have a material adverse effect on our financial position and operating results. There is a risk that the tax authorities could impose additional taxable income or disallow the deductibility of expenses on intercompany transactions resulting in higher tax obligations in one or more tax jurisdictions. Management’s experience has been that the tax authorities can be aggressive in taking positions that would increase taxable income and/or disallow

deductible expenses. If the tax authorities are successful in increasing taxable income and/or disallowing deductible expenses in one or more jurisdictions, it could result in the Company experiencing a higher effective tax rate that could be material. Management regularly consults with professional tax advisors when establishing tax filing positions and believes that the tax filing positions taken are in accordance with tax regulations; however, there is always a risk that the tax authorities could disagree with the tax filing positions taken resulting in additional taxes, interest and penalty becoming due and such amount could be material.

As an Irish incorporated and tax resident company, we are subject to Irish corporate taxation on our worldwide profits. Due to the nature of our business, we have generated losses since inception and therefore have not paid any Irish corporation tax. As of March 31, 2021, we had unused net operating losses of $2 million. Subject to any relevant utilization criteria and restrictions (including those that can restrict the use of carried forward losses where there is a change of ownership of more than half of our ordinary shares and a major change in the nature, conduct or scale of the trade), we expect these to be eligible for carry-forward and utilization against future operating profits.

As a company that carries out extensive research and development activities, we seek to benefit from the Irish research and development tax credit for certain expenditure on research and development activities, plant and machinery and buildings as set out in the Taxes Consolidation Act 1997 of Ireland, or the TCA, and the Taxes Consolidation Act 1997 (Prescribed Research and Development Activities Regulations) 2004. Credit is given at 25% of allowable expenditure subject to satisfying the applicable conditions.

We may benefit from Ireland’s Knowledge Development Box regime in the future, under which an eligible company will be entitled to a corporate tax deduction equal to 50% of its qualifying profits. Qualifying profits are profits directly attributable to the exploitation of certain types of IP (patents, copyrighted computer software) that have been developed by the Irish company through qualifying R&D activities undertaken by the Irish company. In effect, such qualifying profits are taxed at 6.25% where the conditions of the regime are met. The availability of the relief is fact dependent and we will consider the applicability of this relief as our activities progress.

When taken in combination with the research and development tax credit, we expect a long-term rate of Irish corporation tax lower than the statutory rate to apply to us. If, however, there are unexpected adverse changes to the Irish research and development tax credit regime or the Knowledge Development Box regime, or for any reason we are unable to qualify for such regimes, or we are unable to use net operating loss and tax credit carry-forwards and certain built-in losses to reduce future tax payments then our business, results of operations and financial condition may be adversely affected. This may impact our ongoing requirement for investment and the timeframes within which additional investment is required.

Violations of any U.S. federal laws and regulations could result in significant fines, penalties, administrative sanctions, convictions or settlements arising from civil proceedings conducted by either the federal government or private citizens, or criminal charges, including, but not limited to, seizure of assets, disgorgement of profits, cessation of business activities or divestiture. As an entity that conducts business involving 5-MeO-DMT, we are potentially subject to federal and state forfeiture laws (criminal and civil) that permit the government to seize the proceeds of criminal activity. Civil forfeiture laws could provide an alternative for the federal government or any state (or local police force) that wants to discourage residents from conducting transactions with 5-MeO-DMT- related businesses but believes criminal liability is too difficult to prove beyond a reasonable doubt. Also, an individual can be required to forfeit property considered to be the proceeds of a crime even if the individual is not convicted of the crime, and the standard of proof in a civil forfeiture matter is lower than the standard in a criminal matter. Depending on the applicable law, whether federal or state, rather than having to establish liability beyond a reasonable

doubt, the federal government or the state, as applicable, may be required to prove that the money or property at issue is proceeds of a crime only by either clear and convincing evidence or a mere preponderance of the evidence.

Investors located in jurisdictions where 5-MeO-DMT remains illegal may be at risk of prosecution under conspiracy, aiding and abetting, and money laundering statutes, and be at further risk of losing their investments or proceeds under forfeiture statutes. Many jurisdictions remain fully able to take action to prevent the proceeds of 5-MeO-DMT businesses from entering their state. Our investors and prospective investors should be aware of these potentially relevant laws in considering whether to invest in us.

Our operations are subject to anti-corruption laws, including the Criminal Justice (Corruption Offences) Act 2018 of Ireland, or Criminal Justice Act, the U.S. Foreign Corrupt Practices Act, or FCPA, the UK Bribery Act 2010, or UK Bribery Act, and other anti-corruption laws that apply in countries where we do business and may do business in the future. The Criminal Justice Act, FCPA and these other laws generally prohibit us, our officers, and our employees and intermediaries from bribing, being bribed or making other prohibited payments to government officials or other persons to obtain or retain business or gain some other business advantage.

The Criminal Justice Act, the FCPA and these other laws generally prohibit us and our employees and intermediaries from authorizing, promising, offering, or providing, directly or indirectly, a financial or other advantage to government officials or other persons to induce them to improperly perform a relevant function or activity (or reward them for such behavior).

Under the Criminal Justice Act and under the UK Bribery Act we may also be liable for failing to prevent a person associated with us from committing a bribery offense. We, along with those acting on our behalf and our commercial partners, operate in a number of jurisdictions that pose a high risk of potential Criminal Justice Act or FCPA or UK Bribery Act violations, and we participate in collaborations and relationships with third parties whose corrupt or illegal activities could potentially subject us to liability under the Criminal Justice Act, FCPA, UK Bribery Act or local anti-corruption laws, even if we do not explicitly authorize or have actual knowledge of such activities. In addition, we cannot predict the nature, scope or effect of future regulatory requirements to which our international operations might be subject or the manner in which existing laws might be administered or interpreted.

Compliance with the FCPA and the UK Bribery Act in particular, is expensive and difficult, particularly in countries in which corruption is a recognized problem. In addition, the FCPA and the UK Bribery Act present particular challenges in the pharmaceutical industry, because, in many countries, hospitals are operated by the government, and doctors and other hospital employees are considered foreign officials. Certain payments to hospitals in connection with clinical trials and other work have been deemed to be improper payments to government officials and have led to FCPA enforcement actions.

In the future, we may operate in jurisdictions that pose a high risk of potential Criminal Justice Act, FCPA or UK Bribery Act violations, and we may participate in collaborations and relationships with third parties whose actions could potentially subject us to liability under the Criminal Justice Act, FCPA, UK Bribery Act or local anti-corruption laws. In addition, we cannot predict the nature, scope or effect of future regulatory requirements to which our international operations might be subject or the manner in which existing laws might be administered or interpreted. If we expand our operations, we will need to dedicate additional resources to comply with numerous laws and regulations in each jurisdiction in which we plan to operate.

We are also subject to other laws and regulations governing our international operations, including regulations administered by the governments of the United Kingdom and the United States, and authorities in member states of the European Union, including applicable export control regulations, economic sanctions on countries and persons, customs requirements and currency exchange regulations, collectively referred to as the Trade Control laws. In addition, various laws, regulations and executive orders also restrict the use and dissemination outside of the United States, or the sharing with certain non-U.S. nationals, of information classified for national security purposes, as well as certain products and technical data relating to those products. If we expand our presence outside of the United States, it will require us to dedicate additional resources to comply with these laws, and these laws may preclude us from manufacturing GH001 or GH002 and developing and selling GH001, GH002 or any future product candidates outside of the United States, which could limit our growth potential and increase our development costs.

There is no assurance that we will be completely effective in ensuring our compliance with all applicable anti-corruption laws, including the Criminal Justice Act, the FCPA, the UK Bribery Act or other legal requirements, including Trade Control laws. If we are not in compliance with the Criminal Justice Act, the FCPA, the UK Bribery Act and other anti-corruption laws or Trade Control laws, we may be subject to criminal and civil penalties, disgorgement and other sanctions and remedial measures, and legal expenses, which would have an adverse impact on our business, financial condition, results of operations and liquidity. The SEC also may suspend or bar issuers from trading securities on U.S. exchanges for violations of the FCPA’s accounting provisions. Any investigation of any potential violations of the Criminal Justice Act, the FCPA, other anti-corruption laws or Trade Control laws by Irish, U.S. or other authorities could also have an adverse impact on our reputation, our business, results of operations and financial condition.

Although we do not currently have any products on the market, upon commercialization of our product candidates, if approved, we will be subject to additional healthcare statutory and regulatory requirements and oversight by federal and state governments in the United States as well as foreign governments in the jurisdictions in which we conduct our business. Healthcare providers, physicians and third-party payors in the United States and elsewhere will play a primary role in the recommendation and prescription of any product candidates for which we obtain marketing approval. Our current and future arrangements with healthcare providers, third-party payors, customers and others may expose us to broadly applicable fraud and abuse and other healthcare laws and regulations. In particular, the research of our product candidates, as well as the promotion, sales and marketing of healthcare items and services, as well as certain business arrangements in the healthcare industry, are subject to extensive laws designed to prevent fraud, kickbacks, self-dealing and other abusive practices. These laws and regulations may restrict or prohibit a wide range of pricing, discounting, marketing and promotion, structuring and commission(s), certain customer incentive programs and other business or financial arrangements.

The applicable federal, state and foreign healthcare laws and regulations laws that may affect our ability to operate include, but are not limited to:

The distribution of biopharmaceutical products is subject to additional requirements and regulations, including extensive record keeping, licensing, storage and security requirements intended to prevent the unauthorized sale of biopharmaceutical products.

If the FDA, EMA or a comparable foreign regulatory authority approves any of our product candidates, we will be subject to an expanded number of these laws and regulations and will need to expend resources to develop and implement policies and processes to promote ongoing compliance. The scope and enforcement of each of these laws is uncertain and subject to rapid change in the current environment of healthcare reform, especially in light of the lack of applicable precedent and regulations. Ensuring business arrangements comply with applicable healthcare laws, as well as responding to possible investigations by government authorities, can be time- and resource-consuming and can divert a company’s attention from the business.

It is possible that governmental and enforcement authorities will conclude that our business practices, including our arrangements with physicians and other healthcare providers, some of whom may receive stock options as compensation for services provided, may not comply with current or future statutes, regulations or case law interpreting applicable fraud and abuse or other healthcare laws and regulations. If our operations are found to be in violation of any of the laws described above or any other government regulations that apply to us, we may be subject to significant sanctions, including civil, criminal and administrative penalties, damages, fines, disgorgement, imprisonment, reputational harm,

exclusion from participation in federal and state funded healthcare programs, contractual damages and the curtailment or restricting of our operations, as well as additional reporting obligations and oversight if we become subject to a corporate integrity agreement or other agreement to resolve allegations of non-compliance with these laws. Further, if any of the physicians or other healthcare providers or entities with whom we expect to do business are found to be not in compliance with applicable laws, they may be subject to similar penalties. Any action for violation of these laws, even if successfully defended, could cause us to incur significant legal expenses and divert management’s attention from the operation of the business. In addition, the approval and commercialization of any product candidate we develop outside the United States will also likely subject us to foreign equivalents of the healthcare laws mentioned above, among other foreign laws. All of these could harm our ability to operate our business and our financial results.

Efforts to ensure that our business arrangements with third parties will comply with applicable healthcare laws and regulations will involve substantial costs. Any action against us for violation of these laws, even if we successfully defend against it, could cause us to incur significant legal expenses and divert our management’s attention from the operation of our business. The shifting compliance environment and the need to build and maintain robust and expandable systems to comply with multiple jurisdictions with different compliance or reporting requirements increases the possibility that a healthcare company may run afoul of one or more of the requirements.

We and any potential collaborators may be subject to U.S. and foreign federal, state and local laws and regulations that address privacy and data security. In the United States, numerous federal and state laws and regulations, including state data breach notification laws, state health and personal information privacy laws, and federal and state consumer protection laws, govern the collection, use, processing, storage, transmission, disclosure, destruction and protection of health-related and other personal information. In addition, we may obtain health information from third parties, including research institutions from which we obtain clinical trial data, which are subject to privacy and security requirements under HIPAA, as amended by HITECH. To the extent that we act as a business associate we may also be subject to the privacy and security provisions of HIPAA, as amended by HITECH, which restricts the use and disclosure of patient-identifiable health information, mandates the adoption of certain standards relating to the privacy and security of patient-identifiable health information, and requires the reporting of certain security breaches to healthcare provider customers with respect to such information. Additionally, many states have enacted similar laws that may impose more stringent requirements on entities like ours. Depending on the facts and circumstances, we could be subject to significant civil, criminal, and administrative penalties if we obtain, use, or disclose individually identifiable health information maintained by a HIPAA-covered entity in a manner that is not authorized or permitted by HIPAA.

Additionally, in June 2018, the State of California enacted the California Consumer Privacy Act of 2018, or CCPA, which came into effect on January 1, 2020 and provides new data privacy rights for California consumers (as that term is defined in the legislation) and new operational requirements for companies that process information of California residents, which may increase our compliance costs and potential liability. The CCPA gives California residents expanded rights to access and delete their personal information, opt out of certain personal information sharing, and receive detailed information about how their personal information is used. The CCPA provides for civil penalties for violations, as well as a private right of action and statutory damages for data breaches that is expected to increase data breach litigation. While there is currently an exception under the CCPA for protected health information that is subject to HIPAA and clinical trial regulations, as currently written, the CCPA may nevertheless impact certain of our business activities depending on how the CCPA will be interpreted, and exemplifies the vulnerability of our business to the evolving regulatory environment related to personal information. In addition, California voters recently approved the California Privacy Rights Act of 2020, or CPRA, which goes into effect on January 1, 2023. Unless amended, the CPRA will impose additional obligations on companies covered by

the legislation and significantly modify the CCPA, including by expanding consumers’ rights with respect to certain sensitive personal information. The CPRA also creates a new state agency that will be vested with authority to implement and enforce the CCPA and CPRA. Some observers have noted that the CCPA and CPRA could mark the beginning of a trend toward more stringent state privacy legislation in the United States, which could increase our potential liability and adversely affect our business. Other states and the U.S. federal government are considering comprehensive privacy laws, and on March 2, 2021, the Virginia Consumer Data Protection Act, or CDPA, was signed into law. The CDPA becomes effective January 1, 2023 and contains provisions that require businesses subject to the legislation to conduct data protection assessments in certain circumstances and that require opt-in consent from Virginia consumers to process certain sensitive personal information.

The collection, use, storage, disclosure, transfer, or other processing of personal data (including health data processed in the context of clinical trials) regarding EU data subjects in the European Economic Area, or EEA, and/or carried out in the context of the activities of our establishment in any EEA member state, is subject to the GDPR, which became effective on May 25, 2018.

The GDPR is wide-ranging in scope and imposes numerous additional requirements on companies that process personal data of individuals residing in Europe, including imposing special requirements in respect of the processing of health and other sensitive data, requiring that consent of individuals to whom the personal data relates is obtained in certain circumstances, requiring additional disclosures to individuals regarding data processing activities, requiring that appropriate safeguards are implemented to protect the security and confidentiality of personal data, creating mandatory data breach notification requirements in certain circumstances, and requiring that certain measures (including contractual requirements) are put in place when engaging third-party data processors. The GDPR permits data protection authorities to impose large penalties for violations of the GDPR, including potential fines of up to €20 million or 4% of annual global revenue, whichever is greater. The GDPR also provides individuals with various rights in respect of their personal data, including rights of access, erasure, portability, rectification, restriction and objection, and confers a private right of action on data subjects and consumer associations to lodge complaints with supervisory authorities, seek judicial remedies, and obtain compensation for damages resulting from violations of the GDPR. The GDPR requirements apply not only to third-party transactions, but also to transfers of information between us and our subsidiaries, including employee information.

The GDPR also imposes strict rules on the transfer of personal data to countries outside the European Economic Area, including the United States, unless the parties to the transfer have implemented safeguards to protect the transferred personal information. The Court of Justice of the European Union, or CJEU, recently raised questions about whether the European Commission’s Standard Contractual Clauses, one of the primary mechanisms used by companies to import personal information from Europe, complies with the GDPR. While the CJEU upheld the validity of the Standard Contractual Clauses, the CJEU ruled that the underlying data transfers must be assessed on a case-by-case basis by the data controller to determine whether the personal information will be adequately protected. Further, the European Commission recently proposed updates to the Standard Contractual Clauses. At present, there are few if any viable alternatives to the Standard Contractual Clauses and there is uncertainty regarding how to ensure that transfers of personal information from Europe to the United States might be adequately protected so as to comply with the GDPR. As such, any transfers by us, or our vendors, of personal information from Europe may not comply with European data protection laws and may increase our exposure to the GDPR’s heightened sanctions for violations of its cross-border data transfer restrictions. Loss of our ability to transfer personal information from the European Economic Area may also require us to increase our data processing capabilities in those jurisdictions at significant expense.

Further, the United Kingdom’s withdrawal from the European Union and European Economic Area on January 31, 2020 has created uncertainty with regard to data protection regulation in the United Kingdom. As of January 1, 2021, we are also subject to the UK GDPR and UK Data Protection Act of 2018, which retains the EU GDPR in the United Kingdom’s national law. In particular, the collection, use, storage,

disclosure, transfer, or other processing of personal data (including health data processed in the context of clinical trials) regarding data subjects in the United Kingdom and/or carried out in the context of the activities of our establishment in the United Kingdom is subject to the UK GDPR and the UK Data Protection Act of 2018. However, it is still unclear whether the transfer of personal information from the European Economic Area to the United Kingdom will remain lawful under the GDPR in the longer term, although this is currently subject to a bridge, allowing for lawful transfers until June 30, 2021 while awaiting an adequacy decision from the European Data Protection Board. If adequacy is granted, this will last for a period of four years before being reconsidered.

In addition, Europe and other foreign jurisdictions have enacted laws, regulations, standards and common practices that relate to the privacy of clinical trial data, including as a condition to approve clinical trials. These requirements are evolving and uncertain and they may result in delays to our ability to launch clinical trials or limit the jurisdictions in which we may conduct clinical trials.

The GDPR may increase our responsibility and liability in relation to personal data that we process where such processing is subject to the GDPR. While we have taken steps to comply with the GDPR and implementing legislation in applicable EEA member states, including by seeking to establish appropriate lawful bases for the various processing activities we carry out as a controller or joint controller, reviewing our security procedures and those of our vendors and collaborators, and entering into data processing agreements with relevant vendors and collaborators, we cannot be certain that our efforts to achieve and remain in compliance have been, and/or will continue to be, fully successful.

The regulatory framework for data privacy and security issues in the United States and abroad is rapidly evolving and likely to remain uncertain for the foreseeable future. Compliance with applicable privacy and data protection laws and regulations is a rigorous and time-intensive process and could require us to take on more onerous obligations in our contracts, restrict our ability to collect, use and disclose certain data, or in some cases, impact our ability to operate in certain jurisdictions. Despite our efforts to bring our practices into compliance with these laws and regulations, we may not be successful in our efforts to achieve compliance due to internal or external factors, such as resource allocation limitations or a lack of vendor cooperation. In addition, because the interpretation and application of privacy and data protection laws are still uncertain, it is possible that these laws and other actual or alleged legal obligations, such as contractual or self-regulatory obligations, may be interpreted and applied in a manner inconsistent with our data management practices. Our failure or perceived failure to comply with these laws, regulations and obligations could result in government investigations, proceedings and enforcement actions (which could include civil, criminal and administrative penalties), public statements against us by government entities, private parties, consumer advocacy groups or others, private litigation, contractual penalties, monetary damages and/or adverse publicity, and could negatively affect our operating results and business. Moreover, clinical trial subjects, employees and other individuals about whom we or our potential collaborators obtain personal information, as well as the providers who share this information with us, may limit our ability to collect, use and disclose the information. Claims that we have violated individuals’ privacy rights, failed to comply with data protection laws, or breached our contractual obligations, even if we are not found liable, could be expensive and time-consuming to defend and could result in adverse publicity that could harm our business.

Changes in U.S. and foreign regulations, statutes or the interpretation of existing regulations could impact our business in the future by requiring, for example: (i) changes to our manufacturing arrangements; (ii) additions or modifications to product labeling; (iii) the recall or discontinuation of our products; or (iv) additional record keeping requirements. If any such changes were to be imposed, they could adversely affect the operation of our business.

In the United States and in some foreign jurisdictions, there have been, and likely will continue to be, a number of legislative initiatives and regulatory changes regarding the healthcare system directed at broadening the availability of healthcare, improving the quality of healthcare, and containing or lowering

the cost of healthcare. For example, in March 2010, the ACA was enacted, which substantially changed the way health care is financed by both governmental and private insurers, and significantly impacted the U.S. biopharmaceutical industry. The ACA, among other things, subjects biological products to potential competition by lower-cost biosimilars, expands the types of entities eligible for the 340B drug discount program; introduced a new methodology by which rebates owed by manufacturers under the Medicaid Drug Rebate Program are calculated for drugs that are inhaled, infused, instilled, implanted or injected; increased the minimum Medicaid rebates owed by manufacturers under the Medicaid Drug Rebate Program and extended the rebate program to individuals enrolled in Medicaid managed care organizations; established annual fees and taxes on manufacturers of certain branded prescription drugs; and created a new Medicare Part D coverage gap discount program, in which manufacturers must agree to offer 50% (increased to 70%) point-of-sale discounts off negotiated prices of applicable brand drugs to eligible beneficiaries during their coverage gap period, as a condition for the manufacturer’s outpatient drugs to be covered under Medicare Part D.

Since its enactment, there have been numerous judicial, administrative, executive and legislative challenges to certain aspects of the ACA. Various portions of the ACA are currently undergoing legal and constitutional challenges in the U.S. Supreme Court; the Trump Administration issued several executive orders which eliminated cost sharing subsidies and various provisions that would impose a fiscal burden on states or a cost, fee, tax, penalty or regulatory burden on individuals, healthcare providers, health insurers or manufacturers of pharmaceuticals or medical devices; and Congress considered several pieces of legislation aimed at significantly revising or repealing the ACA. While Congress has not passed comprehensive repeal legislation, several bills affecting the implementation of certain taxes under the ACA have passed. Although the U.S. Supreme Court has not yet ruled on the constitutionality of the ACA, on January 28, 2021, President Biden issued an executive order to initiate a special enrollment period from February 15, 2021 through May 15, 2021 for purposes of obtaining health insurance coverage through the ACA marketplace. The executive order also instructs certain governmental agencies to review and reconsider their existing policies and rules that limit access to healthcare, including among others, reexamining Medicaid demonstration projects and waiver programs that include work requirements, and policies that create unnecessary barriers to obtaining access to health insurance coverage through Medicaid or the ACA. It is unclear how the Supreme Court ruling, other such litigation, and the healthcare reform measures of the Biden administration will impact the ACA and our business.

In addition, other legislative changes have been proposed and adopted in the United States since the ACA was enacted. For example, on August 2, 2011, the Budget Control Act of 2011, among other things, created measures for spending reductions by Congress. A Joint Select Committee on Deficit Reduction, tasked with recommending a targeted deficit reduction of at least $1.2 trillion for the years 2013 through 2021, was unable to reach required goals, thereby triggering the legislation’s automatic reduction to several government programs, including aggregate reductions of Medicare payments to providers of up to 2% per fiscal year. These reductions went into effect on April 1, 2013 and, due to subsequent legislative amendments to the statute, will remain in effect through 2030, unless additional Congressional action is taken. However, pursuant to Congressional action, these Medicare sequester reductions were suspended through December 31, 2021 due to the COVID-19 pandemic. On January 2, 2013, the American Taxpayer Relief Act of 2012 was signed into law, which, among other things, further reduced Medicare payments to several types of providers, including hospitals and cancer treatment centers, and increased the statute of limitations period for the government to recover overpayments to providers from three to five years. Additionally, the BBA, among other things, amended the ACA, effective January 1, 2019, by increasing the point-of-sale discount (from 50% under the ACA to 70%) that is owed by pharmaceutical manufacturers who participate in Medicare Part D and closing the coverage gap in most Medicare drug plans, commonly referred to as the “donut hole.”

Moreover, payment methodologies may be subject to changes in healthcare legislation and regulatory initiatives. For example, CMS may develop new payment and delivery models, such as bundled payment models. Recently, there has been heightened governmental scrutiny over the manner in which manufacturers set prices for their products. Such scrutiny has resulted in several recent U.S. Congressional inquiries and proposed and enacted federal and state legislation designed to, among other

things, bring more transparency to drug pricing, reduce the cost of prescription drugs under Medicare, review the relationship between pricing and manufacturer patient programs, and reform government program reimbursement methodologies for drugs. For example, the Trump administration used several means to propose or implement drug pricing reform, including through federal budget proposals, executive orders and policy initiatives. For example, on July 24, 2020 and September 13, 2020, the Trump administration announced several executive orders related to prescription drug pricing that attempt to implement several of the administration’s proposals. The FDA also released a final rule, effective November 30, 2020, implementing a portion of the importation executive order providing guidance for states to build and submit importation plans for drugs from Canada. Further, on November 20, 2020, HHS finalized a regulation removing safe harbor protection for price reductions from pharmaceutical manufacturers to plan sponsors under Part D, either directly or through pharmacy benefit managers, unless the price reduction is required by law. The implementation of the rule has been delayed by the Biden administration from January 1, 2022 to January 1, 2023 in response to ongoing litigation. The rule also creates a new safe harbor for price reductions reflected at the point-of-sale, as well as a new safe harbor for certain fixed fee arrangements between pharmacy benefit managers and manufacturers, the implementation of which have also been delayed until January 1, 2023. On November 20, 2020, CMS issued an interim final rule implementing President Trump’s Most Favored Nation executive order, which would tie Medicare Part B payments for certain physician-administered drugs to the lowest price paid in other economically advanced countries, effective January 1, 2021. On December 28, 2020, the U.S. District Court in Northern California issued a nationwide preliminary injunction against implementation of the interim final rule. It is unclear whether the Biden administration will work to reverse these measures or pursue similar policy initiatives. Although a number of these and other measures may require additional authorization to become effective, Congress and the Biden administration have each indicated that it will continue to seek new legislative and/or administrative measures to control drug costs.

At the state level in the United States, legislatures are increasingly passing legislation and implementing regulations designed to control pharmaceutical and biologic product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain product access and marketing cost disclosure and transparency measures, and, in some cases, designed to encourage importation from other countries and bulk purchasing. Legally mandated price controls on payment amounts by third-party payors or other restrictions on coverage or access could harm our business, results of operations, financial condition and prospects. In addition, regional healthcare authorities and individual hospitals are increasingly using bidding procedures to determine what pharmaceutical products and which suppliers will be included in their prescription drug and other healthcare programs. This could reduce the ultimate demand for our product candidates that we successfully commercialize or put pressure on our product pricing.

In the European Union, similar political, economic and regulatory developments may affect our ability to profitably commercialize our product candidates, if approved. In addition to continuing pressure on prices and cost containment measures, legislative developments at the EU or member state level may result in significant additional requirements or obstacles that may increase our operating costs. The delivery of healthcare in the European Union, including the establishment and operation of health services and the pricing and reimbursement of medicines, is almost exclusively a matter for national, rather than EU, law and policy. National governments and health service providers have different priorities and approaches to the delivery of health care and the pricing and reimbursement of products in that context. In general, however, the healthcare budgetary constraints in most EU member states have resulted in restrictions on the pricing and reimbursement of medicines by relevant health service providers. Coupled with ever-increasing EU and national regulatory burdens on those wishing to develop and market products, this could prevent or delay marketing approval of our product candidate, restrict or regulate post-approval activities and affect our ability to commercialize any products for which we obtain marketing approval. In international markets, reimbursement and healthcare payment systems vary significantly by country, and many countries have instituted price ceilings on specific products and therapies.

Legislation changes may also affect the legal requirements under which we perform our technical, nonclinical and clinical development of our product candidates and the medical devices required to deliver such product candidates, and they may affect how the FDA, EMA and comparable foreign regulatory agencies review and approve new drug products, drug-device combination products or medical devices.

For example, on April 5, 2017, the European Parliament passed the MDR, which repeals and replaces the EU Medical Devices Directive and the Active Implantable Medical Devices Directive. Unlike directives, which must be implemented into the national laws of the EEA member states, the regulations would be directly applicable, i.e., without the need for adoption of EEA member state laws implementing them, in all EEA member states and are intended to eliminate current differences in the regulation of medical devices among EEA member states. The MDR, among other things, is intended to establish a uniform, transparent, predictable and sustainable regulatory framework across the European Economic Area for medical devices and ensure a high level of safety and health while supporting innovation.

The MDR is currently scheduled to become applicable on May 26, 2021. Once applicable, the new regulations will, among other things:

These modifications may have a significant effect on the way we can develop our product candidates and the medical devices required to deliver such product candidates, and may delay our development significantly.

In the United Kingdom, medical devices will continue to be regulated by laws equivalent to the EU directives and the government is consulting on new laws which are planned to take effect from the end of December 2022. These new laws will impose an additional regulatory burden for any products we intend to market in Great Britain, as Northern Ireland will remain subject to EU law.

In addition, the European Union has adopted the Clinical Trials Regulation, or Regulation 536/2014, or CTR, in April 2014, which is expected to come into application in 2022. The CTR will be directly applicable in all the EU member states, repealing the current Clinical Trials Directive. Conduct of all clinical trials performed in the European Union will continue to be bound by currently applicable provisions until the new CTR becomes applicable. The extent to which ongoing clinical trials will be governed by the CTR will depend on when the CTR becomes applicable and on the duration of the individual clinical trial. If a clinical trial continues for more than three years from the day on which the CTR becomes applicable the CTR will at that time begin to apply to the clinical trial. The CTR harmonizes the assessment and supervision processes for clinical trials throughout the European Union via a Clinical Trials Information System, which will notably contain a centralized EU portal and database.

We cannot predict the likelihood, nature or extent of government regulation that may arise from future legislation or administrative action in the United States or in any other jurisdictions. If we or any third parties we may engage are slow or unable to adapt to changes in existing requirements or the adoption of new requirements or policies, or if we or such third parties are not able to maintain regulatory compliance, our product candidates may lose any regulatory approval that may have been obtained and we may not achieve or sustain profitability.

The ability of the FDA to review and approve new products can be affected by a variety of factors, including government budget and funding levels, ability to hire and retain key personnel and accept the payment of user fees, and statutory, regulatory and policy changes. In addition, government funding of the SEC and other government agencies on which our operations may rely, including those that fund research and development activities, is subject to the political process, which is inherently fluid and unpredictable.

Disruptions at the FDA and other agencies may also slow the time necessary for new drugs to be reviewed or approved by necessary government agencies, which would adversely affect our business. For example, over the last several years, the U.S. federal government has shut down several times and certain regulatory agencies, such as the FDA have had to furlough critical employees and stop critical activities. Separately, in response to the COVID-19 pandemic, on March 10, 2020, the FDA announced its intention to temporarily postpone most inspections of foreign manufacturing facilities along with routine surveillance inspections of domestic manufacturing facilities. On July 10, 2020, the FDA announced its goal of restarting domestic onsite inspections during the week of July 20, but such activities would depend on data about the virus’ trajectory in a given state and locality and the rules and guidelines that are put in place by state and local governments. The FDA has developed a rating system to assist in determining when and where it is safest to conduct prioritized domestic inspections. In April 2020, the FDA stated that its New Drug Program was continuing to meet program user fee performance goals, but due to many agency staff working on COVID-19 activities, it was possible that the FDA would not be able to sustain that level of performance indefinitely. Regulatory authorities outside the United States may adopt similar restrictions or other policy measures in response to the COVID-19 pandemic and may experience delays in their regulatory activities. If a prolonged government shutdown occurs, or if global health concerns continue to prevent the FDA or other regulatory authorities from conducting their regular inspections, reviews or other regulatory activities, it could significantly impact the ability of the FDA to timely review and process our regulatory submissions, which could have a material adverse effect on our business. Further, upon completion of this offering and in our operations as a public company, future government shutdowns could impact our ability to access the public markets and obtain necessary capital in order to properly capitalize and continue our operations.

We ultimately intend to seek approval to market our product candidates in both the United States and in selected foreign jurisdictions. If we obtain approval in one or more foreign jurisdictions for our product candidates, we will be subject to rules and regulations in those jurisdictions. In some foreign countries, particularly those in the European Union, the pricing of drugs is subject to governmental control and other market regulations which could put pressure on the pricing and usage of our product candidates. In these countries, pricing negotiations with governmental authorities can take considerable time after obtaining marketing approval of a product candidate. In addition, market acceptance and sales of our product candidates will depend significantly on the availability of adequate coverage and reimbursement from third-party payors for our product candidates and may be affected by existing and future healthcare reform measures.

Much like the federal Anti-Kickback Statute prohibition in the United States, the provision of benefits or advantages to physicians to induce or encourage the prescription, recommendation, endorsement, purchase, supply, order or use of medicinal products is also prohibited in the European Union. The provision of benefits or advantages to physicians is governed by the national anti-bribery laws of EU member states, and in respect of the United Kingdom (which is no longer a member of the European Union), the UK Bribery Act of 2010. Infringement of these laws could result in substantial fines and imprisonment.

Payments made to physicians in certain EU member states must be publicly disclosed. Moreover, agreements with physicians often must be the subject of prior notification and approval by the physician’s employer, his or her competent professional organization and/or the regulatory authorities of the individual EU member states. These requirements are provided in the national laws, industry codes or professional codes of conduct, applicable in the EU member states. Failure to comply with these requirements could result in reputational risk, public reprimands, administrative penalties, fines or imprisonment.

In addition, in most foreign countries, including those in the European Union, the United Kingdom and the European Economic Area, the proposed pricing for a drug must be approved before it may be lawfully marketed. The requirements governing drug pricing and reimbursement vary widely from country to country. For example, the European Union provides options for its member states to restrict the range of medicinal products for which their national health insurance systems provide reimbursement and to control the prices of medicinal products for human use. Reference pricing used by various EU member states and parallel distribution, or arbitrage between low-priced and high-priced member states, can further reduce prices. A member state may approve a specific price for the medicinal product or it may instead adopt a system of direct or indirect controls on the profitability of the company placing the medicinal product on the market. In some countries, we may be required to conduct a clinical study or other studies that compare the cost effectiveness of any of our product candidates to other available therapies in order to obtain or maintain reimbursement or pricing approval. There can be no assurance that any country that has price controls or reimbursement limitations for biopharmaceutical products will allow favorable reimbursement and pricing arrangements for any of our products. Historically, products launched in the European Union do not follow price structures of the United States and generally prices tend to be significantly lower. Publication of discounts by third-party payors or authorities may lead to further pressure on the prices or reimbursement levels within the country of publication and other countries. If pricing is set at unsatisfactory levels or if reimbursement of our products is unavailable or limited in scope or amount, our revenues from sales and the potential profitability of any of our product candidates in those countries would be negatively affected.

On June 23, 2016, the United Kingdom held a referendum in which a majority of the eligible members of the electorate voted to leave the European Union, commonly referred to as Brexit. Pursuant to Article 50 of the Treaty on European Union, the United Kingdom ceased being a member state of the European Union on January 31, 2020. The implementation period began February 1, 2020 and continued until December 31, 2020, during which the United Kingdom continued to follow all of the European Union’s rules, the European Union’s pharmaceutical law remained applicable to the United Kingdom and the United Kingdom’s trading relationship remained the same. The United Kingdom and the European Union have signed an EU-UK Trade and Cooperation Agreement, or TCA, which became provisionally applicable on January 1, 2021 and will become formally applicable once ratified by both the United Kingdom and the European Union. This agreement provides details on how some aspects of the United Kingdom and European Union’s relationship will operate going forward, however there are still many uncertainties and how the TCA will take effect in practice is still largely unknown. The lack of clarity with future UK laws and regulations and their interaction with the EU laws and regulations may negatively impact foreign direct investment in the United Kingdom, increase costs, depress economic activity and restrict access to capital.

The uncertainty concerning the United Kingdom’s legal, political and economic relationship with the European Union after Brexit may be a source of instability in the international markets, create significant currency fluctuations, and/or otherwise adversely affect trading agreements or similar cross-border co-operation arrangements (whether economic, tax, fiscal, legal, regulatory or otherwise) beyond the date of Brexit.

These developments may have a significant adverse effect on global economic conditions and the stability of global financial markets and could significantly reduce global market liquidity and limit the ability of key market participants to operate in certain financial markets. In particular, it could also lead to a period of considerable uncertainty in relation to the UK financial and banking markets, as well as on the regulatory process in Europe. Asset valuations, currency exchange rates and credit ratings may also be subject to increased market volatility.

In addition, if other EU member states pursue withdrawal, barrier-free access in the European Economic Area could be diminished or eliminated. The long-term effects of Brexit will depend on how the terms of the TCA take effect in practice and any further agreements (or lack thereof) between the United Kingdom and the European Union.

Such a withdrawal from the European Union is unprecedented, and it is unclear how the restrictions on the United Kingdom’s access to the European single market for goods, capital, services and labor within the European Union, or single market, and the wider commercial, legal and regulatory environment, will impact our current and future operations (including business activities conducted by third parties and contract manufacturers on our behalf) and clinical activities in the United Kingdom. In addition to the foregoing, our UK operations support our current and future operations and clinical activities in the European Union and European Economic Area, and these operations and clinical activities could be disrupted by Brexit.

We may also face new regulatory costs and challenges that could have an adverse effect on our operations. The United Kingdom will lose the benefits of global trade agreements negotiated by the European Union on behalf of its members, which may result in increased trade barriers that could make our doing business in the United Kingdom more difficult. Since the regulatory framework in the United Kingdom covering quality, safety and efficacy of pharmaceutical products, clinical trials, marketing authorization, commercial sales and distribution of pharmaceutical products is derived from EU directives and regulations, Brexit could materially impact the future regulatory regime with respect to the approval of our product candidates in the United Kingdom now that the UK legislation can diverge from EU legislation.

For instance, Great Britain will now no longer be covered by the centralized procedures for obtaining EEA-wide marketing and manufacturing authorizations from the EMA (under the Northern Irish Protocol, centralized marketing authorizations will continue to be recognized in Northern Ireland) and a separate process for authorization of drug products will be required in Great Britain, resulting in an authorization covering the United Kingdom or Great Britain only. Any delay in obtaining, or an inability to obtain, any regulatory approvals, as a result of Brexit or otherwise, would prevent us from commercializing our product candidates in the United Kingdom and restrict our ability to generate revenue and achieve and sustain profitability. The majority of our nonclinical and manufacturing work is done by CMOs, in the United Kingdom. In particular, the United Kingdom no longer being a part of the EU customs union may result in delays in importation and exportation of our clinical trial materials product candidates, and disruption of the supply chain for our clinical trial materials and product candidates. If any of these outcomes occurs, we may be forced to restrict or delay efforts to seek regulatory approval in the United Kingdom and/or European Union for our product candidates, which could significantly and materially harm our business. Even prior to any change to the United Kingdom’s relationship with the European Union, the announcement of Brexit has created economic uncertainty surrounding the terms of Brexit, and its consequences could adversely impact customer confidence resulting in customers reducing their spending budgets on our product candidates, if approved, which could adversely affect our business, financial condition, results of operations and could adversely affect the market price of our ordinary shares.

We, and third parties working on our behalf, are subject to numerous environmental, health and safety laws and regulations, including those governing laboratory procedures and the handling, use,

storage, treatment and disposal of hazardous materials and wastes. From time to time and in the future, our operations and the operations of third parties operating on our behalf may involve the use of hazardous and flammable materials, including chemicals and biological materials, and may also produce hazardous waste products. Even if we contract with third parties for the disposal of these materials and waste products, we cannot completely eliminate the risk of contamination or injury resulting from these materials. In particular, there is limited toxicology data on 5-MeO-DMT, and the risk of contamination and injury is higher as we and third parties working on our behalf work with 5-MeO-DMT in its aerosolized form. In the event of contamination or injury resulting from the use or disposal of our hazardous materials, we could be held liable for any resulting damages, and any liability could exceed our resources. We also could incur significant costs associated with civil or criminal fines and penalties for failure to comply with such laws and regulations.

We maintain employer’s liability insurance to cover us for costs and expenses we may incur due to injuries to our employees, but this insurance may not provide adequate coverage against potential liabilities. However, we do not maintain insurance for environmental liability or toxic tort claims that may be asserted against us.

In addition, we may incur substantial costs in order to comply with current or future environmental, health and safety laws and regulations. Environmental laws and regulations may impair our research, development or production efforts. In addition, failure to comply with these laws and regulations may result in substantial fines, penalties or other sanctions.

Our commercial success depends in part on obtaining and maintaining patents and other forms of intellectual property rights relating to GH001 and GH002, any future product candidates, methods used to manufacture the underlying therapeutic substances, compositions and methods for treating patients using those substances and therapies and medical devices used to deliver such substances and therapies, or licensing such rights from third parties. Failure to obtain, maintain, protect, enforce or extend adequate patent and other intellectual property rights could materially adversely affect our ability to develop and market GH001, GH002 and any future product candidates, and medical devices to deliver such product candidates. We also rely on trade secrets and know-how to develop and maintain our proprietary and intellectual property position. Any failure to protect our trade secrets and know-how could similarly adversely affect our operations and prospects.

We do not currently own or exclusively license any issued patents, and we cannot be certain that patents will be issued or granted with respect to our or any of our future licensors’ pending and future patent applications, or that issued or granted patents will not later be found to be invalid or unenforceable. The patent position of companies like ours is generally uncertain because it involves complex legal and factual considerations and has, in recent years, been the subject of much litigation. As a result, the issuance, scope, validity, enforceability and commercial value of our patent rights is highly uncertain. The standards applied by the European Patent Office, the United States Patent and Trademark Office, or USPTO, and foreign patent offices in granting patents are not always applied uniformly or predictably. For example, there is no uniform worldwide policy regarding patentable subject matter or the scope of claims allowable in pharmaceutical patents. Consequently, patents may not issue from our pending patent applications, and even if they do issue, such patents may not issue in a form that effectively prevents others from developing or commercializing competing therapies. As such, we do not know the degree of future protection that we will have on our proprietary therapies. This risk is further heightened with respect to our GH001 and GH002 product candidates given that 5-MeO-DMT is a naturally occurring substance and therefore is not subject to patent protection.

The patent prosecution process is expensive, complex and time-consuming, and we and any of our third-party licensors, licensees, or collaboration partners may not be able to prepare, file and prosecute all

necessary or desirable patent applications at a reasonable cost or in a timely manner. It is also possible that we or our licensors, licensees or collaboration partners will fail to identify patentable aspects of inventions made in the course of research, development or commercialization activities before it is too late to pursue patent protection on them. In addition, although we enter into non-disclosure and confidentiality agreements with parties who have access to confidential or patentable aspects of our research and development output, such as our employees, corporate collaborators, outside scientific collaborators, contract manufacturers, consultants, advisors, and other third parties, any of these parties may breach these agreements and disclose such output before a patent application is filed, thereby jeopardizing our ability to seek patent protection. Furthermore, publications of discoveries in the scientific literature often lag behind the actual discoveries, and patent applications in the United States and other jurisdictions are typically not published until 18 months after filing, or in some cases not published until and unless granted. Therefore, we cannot be certain that we were the first to make the inventions claimed in our patents or pending patent applications, or that we were the first to file for patent protection of such inventions. Similarly, we cannot be certain that for any in-licensed patents or pending patent applications, the named applicant(s) were the first to make the inventions claimed in such patents or pending patent applications or that the named applicant(s) were the first to file for patent protection for such inventions.

Moreover, in some circumstances, we may not have the right to control the preparation, filing, prosecution, maintenance, enforcement and defense of patents and patent applications covering technology that we license from or license to third parties, and may be reliant on our licensors, licensees or collaboration partners to do so. Therefore, these patents and applications may not be prepared, filed, prosecuted, maintained, enforced or defended in a manner consistent with the best interests of our business. If any of our current or future licensors, licensees or collaboration partners fail to establish, maintain or protect such patents and other intellectual property rights, such rights may be reduced or eliminated. If any of our licensors, licensees or collaboration partners are not fully cooperative or disagree with us as to the prosecution, maintenance or enforcement of any patents and other intellectual property rights, such rights could be compromised and our right to develop and commercialize our product candidates that are subject to such license rights could be adversely affected.

The patent examination process may also require us or our licensors, licensees or collaboration partners to narrow the scope of the claims of our or our licensors’, licensees’ or collaboration partners’ pending and future patent applications, which may limit the scope of patent protection that may be obtained. We cannot assure you that all of the potentially relevant prior art relating to our or any of our licensors’, licensees’ or collaboration partners’ patents and patent applications has been found. If such prior art exists, it can invalidate a patent or prevent a patent from issuing from a pending patent application.

The issuance of a patent is not conclusive as to its inventorship, scope, validity or enforceability, and our or any of our licensors’, licensees’ or collaboration partners’ patents may be challenged in the courts or patent offices in the United States and abroad. Even if patents do successfully issue and even if such patents cover GH001, GH002 and any future product candidates, third parties may initiate an opposition, interference, re-examination, post-grant review, inter partes review, nullification or derivation proceedings in court or before patent offices, or similar proceedings challenging the validity, enforceability or scope of such patents, which may result in loss of exclusivity or in patent claims being narrowed, invalidated, or held unenforceable, which could limit our ability to stop others from using or commercializing similar or identical technology and therapies, or limit the duration of patent protection of our technology and product candidates.

Our and our licensors’, licensees’ or collaboration partners’ patent applications cannot be enforced against third parties practicing the technology claimed in such applications unless and until a patent issues from such applications, and then only to the extent the issued claims cover the technology. In addition, patents and other intellectual property rights will not protect our technology, GH001, GH002 or any future product candidates or medical devices to deliver such product candidates if third parties, including our competitors, design around our protected technology, GH001, GH002 or any future product candidates or medical devices to deliver such product candidates without infringing, misappropriating or

otherwise violating our owned or in-licensed patents or other intellectual property rights. Moreover, some of our patents and patent applications may be co-owned with third parties in the future. If we are unable to obtain an exclusive license to any such third-party co-owners’ interest in such patents or patent applications, such co-owners may be able to license their rights to other third parties, including our competitors, and our competitors could market competing therapies and technology. In addition, we may need the cooperation of any such co-owners of our patents in order to enforce such patents against third parties, and such cooperation may not be provided to us. Any of the foregoing could have a material adverse effect on our competitive position, business, financial conditions, results of operations, and prospects.

Because patent applications are confidential for a period of time after filing, and some remain so until issued, we cannot be certain that we or our licensors, licensees or collaborators were or will be the first to file any patent application related to a product candidate. Furthermore, if patent applications of third parties have an effective filing date before March 16, 2013, an interference proceeding can be initiated by such third parties to determine who was the first to invent any of the subject matter covered by the patent claims of our applications. If patent applications of third parties have an effective filing date on or after March 16, 2013, a derivation proceeding can be initiated by such third parties to determine whether our invention was derived from theirs. Even where we have a valid and enforceable patent, we may not be able to exclude others from practicing our invention where the other party can show that they used the invention in commerce before our filing date or the other party benefits from a compulsory license. In addition, we may be subject to third-party challenges regarding our exclusive ownership of our intellectual property. If a third party were successful in challenging our exclusive ownership of any of our intellectual property, we may lose our right to use such intellectual property, such third party may be able to license such intellectual property to other third parties, including our competitors, and our competitors could market competing therapies and technology. Any of the foregoing could have a material adverse effect on our competitive position, business, financial conditions, results of operations, and prospects.

Furthermore, our owned and in-licensed patents may be subject to a reservation of rights by one or more third parties. For example, we may develop, acquire or license intellectual property rights that have been generated through the use of U.S. government funding. As a result, the U.S. government may have certain rights, or march-in rights, to such patent rights and technology. When new technologies are developed with U.S. government funding, the U.S. government generally obtains certain rights in any resulting patents, including a non-exclusive, worldwide, irrevocable license authorizing the U.S. government to use the inventions for non-commercial purposes. These rights may permit the government to disclose our confidential information to third parties and to exercise march-in rights to use or allow third parties to use our technology. The U.S. government can exercise its march-in rights if it determines that action is necessary because we fail to achieve practical application of the government-funded technology, because action is necessary to alleviate health or safety needs, to meet requirements of federal regulations or to give preference to U.S. industry. The U.S. government also has the right to take title to these inventions if the grant recipient fails to disclose the invention to the government or fails to file an application to register the intellectual property within specified time limits. In addition, our rights in such inventions may be subject to certain requirements to manufacture products embodying such inventions in the United States. Any exercise by the government of such rights could harm our competitive position, business, financial condition, results of operations and prospects.

Competitors or other third parties may infringe, misappropriate or otherwise violate our patents, the patents of our licensors or our other intellectual property rights. To protect our competitive position, we may from time to time need to resort to litigation in order to enforce or defend any patents or other intellectual property rights owned by or licensed to us, or to determine or challenge the scope or validity of patents or other intellectual property rights of third parties. Enforcement of intellectual property rights is difficult, unpredictable and expensive, and many of our or our licensors’ or collaboration partners’ adversaries in these proceedings may have the ability to dedicate substantially greater resources to

prosecuting these legal actions and better sustain the costs of such actions than we or our licensors or collaboration partners can. Accordingly, despite our or our licensors’ or collaboration partners’ efforts, we or our licensors or collaboration partners may not prevent third parties from infringing upon, misappropriating or otherwise violating intellectual property rights we own or control, particularly in countries where the laws may not protect those rights as fully as in the United Kingdom, European Union and the United States. We may also fail in enforcing our rights, in which case our competitors and other third parties may be permitted to use our therapies or other technologies without payment to us.

In addition, litigation involving our patents carries the risk that one or more of our patents will be narrowed, held invalid (in whole or in part, on a claim-by-claim basis) or held unenforceable. Such an adverse court ruling could allow third parties to commercialize our therapies or other technologies, and then compete directly with us, without payment to us.

If we were to initiate legal proceedings against a third party to enforce a patent covering one of our product candidates, the defendant could counterclaim that our patent is invalid or unenforceable. In patent litigation in the United States or in Europe, defendant counterclaims alleging invalidity or unenforceability are commonplace. A claim for a validity challenge may be based on failure to meet any of several statutory requirements, for example, lack of novelty, obviousness or non-enablement. Grounds for an unenforceability assertion could be an allegation that someone connected with prosecution of the patent withheld relevant information from the European Patent Office or the USPTO or made a misleading statement during prosecution. Third parties may also raise challenges to the validity of our patent claims before administrative bodies in the United States or abroad, even outside the context of litigation. Such mechanisms include re-examination, post-grant review, inter partes review, interference proceedings, derivation proceedings, and equivalent proceedings in foreign jurisdictions (i.e., opposition proceedings). Such proceedings could result in the revocation of, cancellation of, or amendment to our patents in such a way that they no longer cover GH001, GH002 or any future product candidates or medical devices to deliver such product candidates. The outcome following legal assertions of invalidity and unenforceability during patent litigation or other proceedings is unpredictable. With respect to the validity question, for example, we cannot be certain that there is no invalidating prior art of which we and the patent examiner were unaware during prosecution. If a defendant or third party were to prevail on a legal assertion of invalidity or unenforceability, we would lose at least part, and perhaps all, of the patent protection on GH001, GH002 or one or more of any future product candidates or medical devices to deliver such product candidates. Such a loss of patent protection could have a material adverse impact on our business financial condition, results of operations, and prospects. Further, litigation could result in substantial costs and diversion of management resources, regardless of the outcome, and this could harm our business and financial results.

We may also be subject to claims challenging the inventorship or ownership of our patents and other intellectual property. It is possible that we do not perfect our ownership of all patents, patent applications and other intellectual property. This possibility includes the risk that we do not identify all inventors, or identify incorrect inventors, which may lead to claims disputing inventorship or ownership of our patents, patent applications and other intellectual property by former employees or other third parties. There is also a risk that we do not establish an unbroken chain of title from inventors to us. Errors in inventorship or ownership can sometimes also impact priority claims. If we were to lose the ability to claim priority for certain patent filings, intervening art or other events may preclude us from issuing patents. Litigation may be necessary to defend against these and other claims challenging inventorship or ownership. If we fail in defending any such claims, in addition to monetary damages, we may lose valuable intellectual property rights. Such an outcome could significantly harm our business and financial results.

Periodic maintenance, renewal, annuity and various other governmental fees on any issued or applied-for patents are due to be paid to the European Patent Office, the USPTO and foreign patent

agencies in several stages over the lifetime of a patent. The European Patent Office, the USPTO and various foreign governmental patent agencies also require compliance with a number of procedural, documentary, fee payment and other similar provisions during the patent application process. In certain circumstances, we may rely on our collaboration partners, law firms or other professionals to pay these fees due to the USPTO and comparable foreign patent agencies and to take the necessary action to comply with such requirements with respect to our intellectual property. While instances of inadvertent non-compliance can, in many cases, be cured by payment of a late fee or by other means in accordance with the applicable rules, there are situations in which non-compliance can result in abandonment or lapse of a patent or patent application, resulting in a partial or complete loss of patent rights in the relevant jurisdiction. Non-compliance events that could result in abandonment or lapse of a patent or patent application include failure to respond to official actions within prescribed time limits, non-payment of fees and failure to properly legalize and submit formal documents. If we or our service providers, licensors or collaboration partners fail to maintain the patents and patent applications covering our product candidates, our patent protection could be reduced or eliminated and third parties, including our competitors, might be able to enter the market with similar or identical therapies or technologies, which would have a material adverse effect on our business, financial condition, results of operations, and prospects. In addition, if we fail to apply for or otherwise fail to obtain applicable patent term extensions or adjustments as a result of such non-compliance, we will have a more limited time during which we can enforce our granted patent rights. Further, if we are responsible for patent prosecution and maintenance of patent rights in-licensed to us, any of the foregoing could expose us to liability to the applicable patent owner.

In the United States, if all maintenance fees are paid on time, the natural expiration of a patent is generally 20 years from its earliest U.S. non-provisional filing date. Various extensions may be available, but there can be no assurance that any such extensions will be obtained, and the life of a patent, and the protection it affords, is limited. Even if patents covering our product candidates, their manufacture or use are obtained, once the patent life has expired, we may be open to competition from competitive therapies or technologies. Given the amount of time required for the development, testing and regulatory review of new product candidates, patents protecting such candidates and concomitant therapies might expire before or shortly after such candidates and concomitant therapies are commercialized. As a result, our owned and in-licensed patent portfolio may not provide us with sufficient rights to exclude others from commercializing therapies similar or identical to ours.

Depending upon the timing, duration and conditions of FDA marketing approval of GH001, GH002 and any of our future product candidates and medical devices to deliver such product candidates, one or more U.S. patents that we may own or license in the future may be eligible for a limited patent term extension under the Drug Price Competition and Patent Term Restoration Act of 1984, or the Hatch-Waxman Act. The Hatch-Waxman Act permits a patent term extension of up to five years beyond the normal expiration for a patent covering an approved product as compensation for effective patent term loss during product development and the FDA regulatory review process. The patent term extension cannot extend the remaining term of a patent beyond a total of 14 years from the date of product approval, is limited to the approved indication (or any additional indications approved during the period of extension) and only one patent per approved drug may be extended and only those claims covering the approved drug, a method for using it, or a method of manufacturing it may be extended. Patent term extension may also be available in certain foreign jurisdictions, including the European Union, upon regulatory approval of any product candidates we develop. However, we may not receive an extension because of, for example, failing to exercise due diligence during the testing phase or regulatory review process, failing to apply within applicable deadlines, failing to apply prior to expiration of relevant patents or otherwise failing to satisfy applicable requirements. Moreover, the length of the extension could be less than we request. If we are unable to obtain patent term extension or the term of any such extension is less than we request, the period during which we can enforce our patent rights for that product will not be lengthened and third parties, including our competitors, may obtain approval to market competing

therapies sooner than we expect. As a result, our revenue from applicable therapies could be materially reduced and our business, financial condition, results of operations, and prospects could be materially harmed.

The degree of future protection afforded by our intellectual property rights is uncertain because intellectual property rights have limitations, and may not adequately protect our business or permit us to maintain our competitive advantage. For example:

Should any of these events occur, they could have a material adverse effect on our business, financial condition, results of operations, and prospects.

Many of our consultants, advisors and employees, including our senior management, were previously employed at other biotechnology or pharmaceutical companies, including our competitors and potential competitors. Some of these individuals executed proprietary rights, non-disclosure and non-competition agreements in connection with such previous employment. Although we intend that our consultants,

advisors and employees do not use proprietary information or know-how of their former employers while working for us, we may be subject to claims that we or these individuals have used or disclosed confidential information or intellectual property, including trade secrets or other proprietary information, of any such individual’s former employer. Litigation may be necessary to defend against these claims, regardless of their merit, and we cannot predict whether we would prevail in any such actions. If we fail in prosecuting or defending any such claims, in addition to paying monetary damages, we may lose valuable intellectual property rights or personnel or sustain damages, our development and commercialization efforts may be prevented or delayed, and we could be required to obtain a license from such third party to commercialize our therapies or other technologies. Such a license may not be available on commercially reasonable terms or at all. Even if we successfully prosecute or defend against such claims, litigation could result in substantial costs and distract our management from its day-to-day activities, and may cause negative publicity.

In addition, we may be subject to claims by our current or former employees or contractors asserting an ownership right in our intellectual property as a result of the work they performed on our behalf. While it is our policy to require our employees and contractors who may be involved in the conception or development of intellectual property to execute agreements assigning such intellectual property to us, we may be unsuccessful in executing such an agreement with each party who, in fact, conceives or develops intellectual property that we regard as our own, and we cannot be certain that our agreements with such parties will be upheld in the face of a potential challenge. The assignment of intellectual property rights may not be self-executing, or the assignment agreements may be breached, for which we may not have an adequate remedy, and we may be forced to bring claims against third parties, or defend claims that they may bring against us, to determine the ownership of what we regard as our intellectual property. Such claims could have a material adverse effect on our business, financial condition, results of operations, and prospects.

Our commercial success depends, in part, upon our ability and the ability of our future collaborators to develop, manufacture, market, and sell any product candidates that we may develop and use our proprietary technologies without infringing, misappropriating or otherwise violating the intellectual property and proprietary rights of third parties. The various markets in which we plan to operate are subject to frequent and extensive litigation regarding patents and other intellectual property rights. In the future, we may become party to, or threatened with, adversarial proceedings or litigation regarding intellectual property rights with respect to GH001, GH002 or any future product candidates or medical devices to deliver such product candidates. If the outcome of any such proceeding or litigation is adverse to us, it may affect our ability to compete effectively.

Additionally, our competitive position may suffer if patents issued to third parties, or other third-party intellectual property rights, cover our therapies or elements thereof, our manufacture or uses relevant to our development plans, the targets of GH001, GH002 or any future product candidates, or medical devices to deliver such product candidates, or other attributes of GH001, GH002 or any future product candidates. In such cases, we may not be in a position to develop or commercialize such product candidates unless we successfully pursue litigation to nullify or invalidate the third-party intellectual property right concerned, or enter into a license agreement with the intellectual property right holder, which may not be available on commercially reasonable terms or at all. In the event that a patent has not expired at the time of approval of such product candidate(s) and the patent owner were to bring an infringement action against us, we may have to argue that our product candidates or the manufacture or use of the underlying therapeutic substances do not infringe a valid claim of the patent in question. Alternatively, if we were to challenge the validity of any issued U.S. patent in court, we would need to overcome a statutory presumption of validity that attaches to every U.S. patent. This means that in order to prevail, we would need to present clear and convincing evidence as to the invalidity of the patent’s

claims. The same applies to certain other jurisdictions. Even if we believe third-party intellectual property claims are without merit, there is no assurance that a court would find in our favor on questions of infringement, validity, enforceability, or priority. In the event that a third party successfully asserts its patent against us such that such third party’s patent is found to be valid and enforceable and infringed by our product candidates, unless we obtain a license to such patent, under which we would most likely be required to pay various types of fees, milestones, royalties or other amounts, and which may not be available on commercially reasonable terms or at all, we could be prevented from continuing to develop or commercialize our product candidates.

It is possible that we have failed, and in the future may fail, to identify relevant patents or applications that may be asserted against us. For example, certain U.S. patent applications filed after November 29, 2000 can remain confidential until and unless issued as patents, provided that inventions disclosed in the applications have not and will not be the subject of a corresponding application filed outside the United States. In general, patent applications in the United States and elsewhere are published approximately 18 months after the earliest filing for which priority is claimed, with such earliest filing date being commonly referred to as the priority date. Therefore, patent applications covering our therapies could have been filed by others without our knowledge. Furthermore, we operate in a highly competitive field, and given our limited resources, it is unreasonable to monitor all patent applications in the areas in which we are active. Additionally, pending patent applications which have been published can, subject to certain limitations, be later amended in a manner that could cover our therapies or the use of our therapies.

Third-party intellectual property right holders, including our competitors, may actively bring infringement, misappropriation or violation claims against us based on existing or future intellectual property rights, regardless of their merit. We may not be able to successfully settle or otherwise resolve such infringement claims. If we are unable to successfully settle future claims on terms acceptable to us, we may be required to engage or continue costly, unpredictable and time-consuming litigation and may be prevented from or experience substantial delays in marketing our therapies. Moreover, we may face patent infringement claims from nonpracticing entities that have no relevant drug revenue and against whom our own patent portfolio may thus have no deterrent effect.

If we are unsuccessful in defending any such claim, in addition to being forced to pay damages, we or our licensees may be temporarily or permanently prohibited from commercializing any of our product candidates that were held to be infringing. If possible, we might be forced to redesign GH001, GH002 or any future product candidates or medical devices to deliver such product candidates so that we no longer infringe the intellectual property rights of third parties, or we may be required to seek a license to any such technology that we are found to infringe, which license may not be available on commercially reasonable terms or at all. Even if we or our licensors or collaboration partners obtain a license, it may be non-exclusive, thereby giving our competitors access to the same technologies licensed to us or our licensors or collaboration partners and it could require us to make significant licensing and royalty payments. In addition, we could be found liable for significant monetary damages, including treble damages and attorneys’ fees, if we are found to have willfully infringed a patent or other intellectual property right. We could also be required to indemnify collaborators or contractors against such claims. Claims that we have misappropriated the confidential information or trade secrets of third parties could have a similar material adverse effect on our business, financial condition, results of operations, and prospects. Any of these events, even if we were ultimately to prevail, could require us to divert substantial financial and management resources that we would otherwise be able to devote to our business.

In addition, if the breadth or strength of protection provided by our or our licensors’ or collaboration partners’ patents and patent applications is threatened, it could dissuade companies from collaborating with us to license, develop or commercialize current or future product candidates. Furthermore, because of the substantial amount of discovery required in connection with intellectual property litigation, there is a risk that some of our confidential information could be compromised by disclosure during this type of litigation.

Even if resolved in our favor, litigation or other legal proceedings relating to intellectual property claims may cause us to incur significant expenses and could distract our technical and management personnel from their normal responsibilities. In addition, the uncertainties associated with litigation could compromise our ability to raise the funds necessary to continue our clinical trials, continue our internal research programs or in-license needed technology. There could also be public announcements of the results of hearings, motions or other interim proceedings or developments and if securities analysts or investors perceive these results to be negative, it could have a substantial adverse effect on the price of our ordinary shares. Such litigation or proceedings could substantially increase our operating losses and reduce our resources available for development and commercialization activities. We may not have sufficient financial or other resources to adequately conduct such litigation or proceedings. Some of our competitors may be able to sustain the costs of such litigation or proceedings more effectively than we can because of their substantially greater financial resources. Furthermore, because of the substantial amount of discovery required in connection with intellectual property litigation, there is a risk that some of our confidential information could be compromised by disclosure during this type of litigation. Uncertainties resulting from the initiation and continuation of patent litigation or other intellectual property proceedings could have a material adverse effect on our ability to compete in the marketplace.

In the future, our programs may require the use of intellectual property or proprietary rights held by third parties, and the growth of our business will likely depend in part on our ability to acquire, in-license, maintain and use these intellectual property and proprietary rights.

For our GH001 inhaled product candidate, we currently acquire the device used to create the inhaled aerosol from a third party. The device and our uses thereof may be covered by one or more patents issued to such third party or other third parties, or other intellectual property rights of such third party or other third parties. We do not currently have a commercial supply agreement with this third party, nor have we established license or development agreements with any alternative provider of a suitable device. It is our intention, for GH001 and for any future delivery platforms that include the use of a device, to either in-license technology or work with a contract development and manufacturing organization, or CDMO, to develop in-house delivery. However, we may not be able to develop an alternative in-house delivery device suitable for GH001, and our competitive position may suffer if we are unable to obtain necessary commercial supply agreements, licenses, or development agreements with this third party or other third parties to use a suitable device in our GH001 inhaled product candidate or future product.

In addition, with respect to any patents we may co-own with third parties, we may require licenses to such co-owners’ interest in such patents. We may be unable to acquire or in-license any compositions, methods of use, processes, or other third-party intellectual property rights from third parties that we identify as necessary for GH001, GH002 or any future product candidates or medical devices to deliver such product candidates on commercially reasonable terms or at all. For example, we may collaborate with U.S. and foreign academic institutions to accelerate our nonclinical research or development under written agreements with these institutions. Typically, these institutions provide us with an option to negotiate a license to any of the institution’s rights in technology resulting from the collaboration. Regardless of such option, we may be unable to negotiate a license within the specified timeframe or under terms that are acceptable to us. If we are unable to do so, the institution may offer the intellectual property rights to other parties, potentially blocking our ability to pursue our applicable investigational therapy or program.

The licensing and acquisition of third-party intellectual property rights is a competitive area, and a number of more established companies may pursue strategies to license or acquire third-party intellectual property rights that we may consider attractive or necessary. These established companies may have a

competitive advantage over us due to their size, cash resources and greater clinical development and commercialization capabilities. In addition, companies that perceive us to be a competitor may be unwilling to assign or license rights to us. If we are unable to successfully acquire or obtain a license to third-party intellectual property rights necessary for the development of an investigational therapy or program, or maintain the existing intellectual property rights we have, we may have to abandon development of that investigational therapy or program, which could have a material adverse effect on our business, financial condition, results of operations, and prospects. Furthermore, even if we were able to obtain a license, it could be non-exclusive, thereby giving our competitors and other third parties access to the same technologies licensed to us, and it could require us to make substantial licensing and royalty payments.

As is the case with other companies in our industry, our success is heavily dependent on obtaining, maintaining, protecting and enforcing our intellectual property rights, particularly patents. Obtaining and enforcing patent rights in the pharmaceutical industry involves technological and legal complexity, and is costly, time-consuming and inherently uncertain. Changes in either the patent laws or interpretation of the patent laws in the United States or other jurisdictions could increase the uncertainties and costs surrounding the prosecution of patent applications and the enforcement or defense of issued patents. For example, the America Invents Act, or the AIA, enacted in the United States in 2012 and 2013, has resulted in significant changes to the U.S. patent system.

Prior to the enactment of the AIA, assuming that other requirements for patentability are met, the first to invent the claimed invention was entitled to the patent, while outside the United States, the first to file a patent application was entitled to the patent. After March 16, 2013, under the AIA, the United States transitioned to a “first-to-file” system for deciding which party should be granted a patent when two or more patent applications are filed by different parties claiming the same invention regardless of whether a third party was the first to invent the claimed invention. Under this regime, a third party that files a patent application in the USPTO before us could be awarded a patent covering an invention of ours even if we made the invention before the third party. The AIA requires us to be cognizant going forward of the time from invention to filing of a patent application, but circumstances could prevent us from promptly filing patent applications on our inventions.

Among some of the other significant changes introduced by the AIA are changes that limit where a patentee may file a patent infringement suit and provide additional opportunities for third parties to challenge any pending patent application or issued patent in the USPTO. Such opportunities include allowing third-party submission of prior art to the USPTO during patent prosecution and additional procedures to attack the validity of a patent by USPTO administered post-grant proceedings, including post-grant review, inter partes review and derivation proceedings. Because of a lower evidentiary standard in USPTO proceedings compared to the evidentiary standard in U.S. federal courts necessary to invalidate a patent claim, a third party could potentially provide evidence in a USPTO proceeding sufficient for the USPTO to hold a claim in any of our future U.S. patents invalid even though the same evidence would be insufficient to invalidate the claim if first presented in a district court action. Accordingly, a third party may attempt to use USPTO procedures to invalidate patent claims that would not have been invalidated if first challenged by the third party as a defendant in a district court action. The AIA and its implementation could increase the uncertainties and costs surrounding the prosecution of any of our future U.S. patent applications and the enforcement or defense of any patents that may issue from such patent applications.

Additionally, the U.S. Supreme Court has ruled on several patent cases in recent years, either narrowing the scope of patent protection available in certain circumstances or weakening the rights of patent owners in certain situations. In addition to increasing uncertainty with regard to our ability to obtain patents in the future, this combination of events has created uncertainty with respect to the value of patents, once obtained. Depending on future actions by the U.S. Congress, the federal courts and the

USPTO, or similar authorities in foreign jurisdictions, the laws and regulations governing patents could change in unpredictable ways that could weaken our ability to obtain new patents or to enforce our existing patents and patents that we might obtain in the future.

We are party to development agreements with CDMOs under which we grant such CDMOs non-exclusive rights to use certain of our intellectual property as necessary for such CDMOs to perform their obligations under such agreements, and under which we are granted non-exclusive rights to use certain of such CDMOs’ intellectual property as necessary in order to use and exploit such CDMOs’ deliverables under such agreements. We expect that we may need to enter into additional license or collaboration agreements in the future that may be important to our business. We expect that future license agreements may impose various financial and other obligations on us related to, among other things, therapeutic development and payment of royalties and fees based on achieving certain milestones. In addition, under such future license agreements, we may be prohibited from developing and commercializing therapies that would compete with the therapies licensed under such agreements. If we fail to comply with our obligations under these agreements, our licensor or collaboration partner may have the right to terminate the agreement, including any licenses included in such agreement, and we may face other liabilities for breach of such agreement.

The termination of any license or collaboration agreements or failure to adequately protect our or our collaborators’ rights under such license or collaboration agreements could prevent us from further developing or commercializing GH001, GH002 or any future product candidates or medical devices to deliver such product candidates covered by the agreement or intellectual property licensed thereunder. For example, we may rely on license agreements which grant us rights to certain intellectual property and proprietary materials that we use in connection with the development of our therapies. If such agreements were to terminate, we may be unable to timely license similar intellectual property and proprietary materials from an alternate source, on commercially reasonable terms or at all, and may be required to conduct additional bridging studies on GH001, GH002 or any future product candidates or medical devices to deliver such product candidates or redesign our product candidates, or medical devices, or the methods for manufacturing them, which could delay or otherwise have a material adverse effect on the development and commercialization of GH001, GH002 or any future product candidates or medical devices to deliver such product candidates.

Our existing and future license agreements may also contain sublicenses from third parties which are not the original licensor of the intellectual property at issue. Under these agreements, we must rely on our licensor to comply with its obligations under the primary license agreements under which such third party obtained rights in the applicable intellectual property, where we may have no relationship with the original licensor of such rights. If our licensors fail to comply with their obligations under these upstream license agreements, the original third-party licensor may have the right to terminate the original license, which may terminate the sublicense. If this were to occur, we would no longer have rights to the applicable intellectual property and, in the case of a sublicense, if we were not able to secure our own direct license with the owner of the relevant rights, which we may not be able to do at a reasonable cost or on reasonable terms, it may adversely affect our ability to continue to develop and commercialize GH001, GH002 or any future product candidates or medical devices to deliver such product candidates incorporating the relevant intellectual property.

Disputes may arise regarding intellectual property subject to a license or collaboration agreement, including the following:

In addition, third-party license and collaboration agreements are complex, and certain provisions in such agreements may be susceptible to multiple interpretations. The resolution of any contract interpretation disagreement that may arise could narrow what we believe to be the scope of our rights to the relevant intellectual property or technology, or increase what we believe to be our financial or other obligations under the relevant agreement, either of which could have a material adverse effect on our business, financial condition, results of operations, and prospects. Moreover, if disputes over intellectual property that we have licensed prevent or impair our ability to maintain our current licensing arrangements on commercially acceptable terms, we may be unable to successfully develop and commercialize the affected product candidate, which could have a material adverse effect on our business, financial conditions, results of operations, and prospects.

We consider our trade secrets and proprietary confidential and unpatented know-how to be important to our business. We rely on trade secrets and confidential know-how to protect our proprietary technology, especially where patent protection is believed to be of limited value. However, trade secrets and know-how are difficult to maintain as confidential and we may, at times, have to share our trade secrets and confidential know-how with third parties with whom we collaborate for the development, manufacturing or commercialization of our current or future product candidates or under joint research and development programs.

To protect this type of information against disclosure or misappropriation by third parties and our competitors, our policy is to require our employees, consultants, contractors and advisors to enter into confidentiality agreements with us. However, we cannot guarantee that we have entered into such agreements with each party that may have or have had access to our trade secrets or confidential know-how. Also, current or former employees, consultants, contractors and advisors may unintentionally or willfully disclose our trade secrets and confidential know-how to our competitors and other third parties or breach such agreements, and we may not be able to obtain an adequate remedy for such breaches. Monitoring unauthorized uses and disclosures is difficult, and enforcing a claim that a third party illegally obtained and is using our trade secrets or confidential know-how is difficult, expensive, time-consuming and unpredictable. The enforceability of confidentiality agreements may vary from jurisdiction to jurisdiction and courts outside the United States are sometimes less willing to protect trade secrets. Furthermore, if a competitor or other third party lawfully obtained or independently developed any of our trade secrets or confidential know-how, we would have no right to prevent such competitor or other third party from using that technology or information to compete with us, which could harm our competitive position. Additionally, if the steps taken to maintain our trade secrets are deemed inadequate, we may have insufficient recourse against third parties for misappropriating such trade secrets. If any of our trade secrets were to be disclosed to, or independently developed by a competitor or other third party, or if we otherwise lose protection for our trade secrets, the value of this information may be greatly reduced and our competitive position would be materially and adversely harmed.

Failure to obtain or maintain trade secret protection could adversely affect our competitive position. Moreover, our competitors may independently develop substantially equivalent proprietary information and may even apply for patent protection in respect of the same. If successful in obtaining such patent protection, our competitors could limit our use of our trade secrets or confidential know-how.

We expect to rely on trademarks in the future as a means to distinguish our product candidates that are approved for marketing from the products of our competitors. We have not yet selected trademarks for our product candidates and have not yet begun the process of applying to register trademarks for GH001, GH002 or any future product candidates. Once we select trademarks and apply to register them, our trademark applications may not be approved. Our registered or unregistered trademarks or trade names may be challenged, infringed, circumvented or declared generic or determined to be infringing on other marks, in which case we could be forced to rebrand our products, which could result in loss of brand recognition and could require us to devote resources to advertising and marketing new brands. Accordingly, we may not be able to adequately protect our rights to these trademarks and trade names, which we need to build name recognition by potential partners or customers in our markets of interest. If we are unable to establish name recognition based on our trademarks and trade names, then we may not be able to compete effectively and our business may be adversely affected. If other entities use trademarks similar to ours in different jurisdictions, or have senior rights to ours, it could interfere with our use of our trademarks throughout the world.

We or our licensors have not pursued or maintained, and may not pursue or maintain in the future, patent protection for our product candidates in every country or territory in which we may sell our products, if approved. Filing, prosecuting and defending patents covering product candidates in all countries and jurisdictions throughout the world would be prohibitively expensive and our licensors’ or collaboration partners’ intellectual property rights in some countries outside of, for instance, the member states of the European Patent Convention and the United States, could be less extensive than those in the member states of the European Patent Convention and the United States. Consequently, we may not be able to prevent third parties from practicing our inventions in all countries, or from selling therapies or importing therapeutic compositions made using our inventions in and into, for instance, the member states of the European Patent Convention and the United States, or other jurisdictions. In addition, we may decide to abandon national and regional patent applications before grant. Furthermore, the grant proceeding of each national/regional patent is an independent proceeding which may lead to situations in which applications might in some jurisdictions be refused by the relevant patent offices, while granted by others. It is also quite common that depending on the country, the scope of patent protection may vary for the same product candidate or technology.

Competitors may use our and our licensors’ or collaboration partners’ technologies in jurisdictions where we have not obtained patent protection to develop their own therapies and, further, may export otherwise infringing therapies to territories where we and our licensors or collaboration partners have patent protection, but where enforcement is not as strong as in other jurisdictions. These therapies may compete with GH001, GH002 or any future product candidates, and our and our licensors’ or collaboration partners’ patents or other intellectual property rights may not be effective or sufficient to prevent them from so competing.

The laws of some jurisdictions do not protect intellectual property rights to the same extent as the laws in, for instance, the member states of the European Patent Convention and the United States, and companies have encountered significant difficulties in protecting and defending such rights in such

jurisdictions. If we or our licensors encounter difficulties in protecting, or are otherwise precluded from effectively protecting, the intellectual property rights important for our business in such jurisdictions, the value of these rights may be diminished and we may face additional competition from others in those jurisdictions.

Some countries have compulsory licensing laws under which a patent owner may be compelled to grant licenses to third parties. In addition, some countries limit the enforceability of patents against government agencies or government contractors. In these countries, the patent owner may have limited remedies, which could materially diminish the value of such patent. If we or any of our licensors or collaboration partners is forced to grant a license to third parties with respect to any patents relevant to our business, our competitive position may be impaired and our business and results of operations may be adversely affected.

Proceedings to enforce our and our licensors’ or collaboration partners’ patent rights in foreign jurisdictions could result in substantial costs and divert our and our licensors’ or collaboration partners’ efforts and attention from other aspects of our business, regardless of whether we or our licensors or collaboration partners are successful, and could put our and our licensors’ or collaboration partners’ patents at risk of being invalidated or interpreted narrowly. In addition, such proceedings could put our and our licensors’ or collaboration partners’ patent applications at risk of not issuing and could provoke third parties to assert claims against us or our licensors or collaboration partners. We or our licensors or collaboration partners may not prevail in any lawsuits that we or our licensors or collaboration partners initiate, and the damages or other remedies awarded, if any, may not be commercially meaningful. Any of the foregoing could have a material adverse effect on our business, financial condition, results of operations, and prospects.

We have relied upon and plan to continue to rely upon third parties, such as laboratories, CROs, clinical data management organizations, medical institutions, clinical investigators and consultants, to organize, support or conduct our nonclinical studies and clinical trials and expect to rely on these third parties to conduct nonclinical studies and clinical trials of any other product candidate that we develop. Any of these third parties may terminate their engagements with us under certain circumstances. We may not be able to enter into alternative arrangements or do so on commercially reasonable terms. In addition, there is a natural transition period when a new CRO begins work. As a result, delays may occur, which could negatively impact our ability to meet our expected clinical development timelines and harm our business, financial condition and prospects.

Although our reliance on these third parties for nonclinical and clinical development activities limits our control over these activities, we remain responsible for ensuring that each of our nonclinical studies and clinical trials is conducted in accordance with the applicable protocol, legal and regulatory requirements and scientific standards. Moreover, human clinical research must comply with GCPs for conducting, recording and reporting the results of clinical trials to assure that data and reported results are credible and accurate and that the rights, integrity and confidentiality of trial participants are protected. Regulatory authorities enforce these GCPs through periodic inspections of trial sponsors, principal investigators, clinical trial sites and IRBs. If we or our third-party contractors fail to comply with applicable GCPs, the clinical data generated in our clinical trials may be deemed unreliable and the regulatory authorities may require us to perform additional clinical trials before approving our product candidates, which would delay the regulatory approval process. We cannot be certain that, upon inspection, a regulatory authority will determine that any of our clinical trials comply with GCPs.

The third parties conducting clinical trials on our behalf are not our employees, and except for remedies available to us under our agreements with such contractors, we cannot control whether or not they devote sufficient time, skill and resources to our ongoing development programs. These outside

contractors may not assign as great a priority to our programs or pursue them as diligently as we would if we were undertaking such programs ourselves. These contractors may also have relationships with other commercial entities, including our competitors, for whom they may also be conducting clinical trials or other drug development activities, which could impede their ability to devote appropriate time to our clinical programs. If these third parties, including clinical investigators, do not successfully carry out their contractual duties, meet expected deadlines or conduct our clinical trials in accordance with regulatory requirements or our stated protocols, we may not be able to obtain, or may be delayed in obtaining, regulatory approvals for our product candidates. If that occurs, we will not be able to, or may be delayed in our efforts to, successfully commercialize our product candidates. In such an event, our financial results and the commercial prospects for any product candidates that we seek to develop could be harmed, our costs could increase and our ability to generate revenues could be delayed, impaired or foreclosed.

If our relationships with any third parties conducting our studies are terminated, we may be unable to enter into arrangements with alternative third parties on commercially reasonable terms, or at all. Switching or adding third parties to conduct our studies involves substantial cost and requires extensive management time and focus. In addition, there is a natural transition period when a new third party commences work. As a result, delays occur, which can materially impact our ability to meet our desired nonclinical and clinical development timelines. Although we carefully manage our relationships with third parties conducting our studies, we cannot assure that we will not encounter similar challenges or delays in the future or that these delays or challenges will not have a material and adverse effect on our business, financial condition and results of operations.

We also rely on other third parties to store and distribute drug supplies for our clinical trials. Any performance failure on the part of our distributors could delay clinical development or regulatory approval of our product candidates or commercialization of any resulting products, producing additional losses and depriving us of potential product revenue.

The processes involved in developing and manufacturing our drug substance, product candidates and medical devices required to deliver such product candidates are complex, expensive, highly regulated and subject to multiple risks. Further, as drug substance, product candidates and medical devices required to deliver such product candidates are developed through nonclinical studies, from early-stage clinical trials to late-stage clinical trials towards approval and commercialization, it is common that various aspects of the drug substance, product candidates and medical devices required to deliver such product candidates, such as technical specifications, design, features and manufacturing methods, are altered along the way in an effort to optimize performance, processes and results and to fulfill regulatory requirements, which are stricter for late-stage clinical trials and commercial manufacture than for early-stage trials. We are currently implementing such changes, which carries the risk that they will not achieve the intended objectives, or could lead to delays, and any of these changes could require the conduct of bridging studies and could cause our product candidates to perform differently and affect the results of planned clinical trials or other future clinical trials. Additionally, the manner in which we currently manufacture our drug substance and product candidates and medical devices required to deliver such product candidates may not fulfill regulatory requirements for late-stage clinical trials and for commercial use, and there can be no assurance that we will be able to manufacture our drug substance and product candidates in a manner that would fulfill such regulatory requirements in a timely manner, or at all. We

have limited experience in drug formulation or manufacturing. Currently, we rely on an extensive network of consultants and contract manufacturers, and in some cases sole source suppliers, for the production of our drug substance, product candidates and medical devices required to deliver such product candidates for current and planned clinical trials.

In order to conduct clinical trials of our product candidates, or supply commercial products, if approved, we will need to manufacture them and the drug substance contained in our product candidates in large quantities. Our CDMOs may be unable to successfully increase the manufacturing capacity for our drug substance and any of our product candidates in a timely or cost-effective manner, or at all. In addition, quality issues may arise during scale-up activities. If our CDMOs are unable to successfully scale up the manufacture of our drug substance or product candidates in sufficient quality and quantity, the development, testing and clinical trials of that product candidate may be delayed or become infeasible, and regulatory approval or commercial launch of any resulting product may be delayed or not obtained, which could significantly harm our business. The same risk would apply to our internal manufacturing facilities, should we decide to build internal manufacturing capacity in the future. In addition, building internal manufacturing capacity would carry significant risks in terms of being able to plan, design and execute on a complex project to build manufacturing facilities in a timely and cost-efficient manner, and the resources associated with ensuring the ongoing regulatory compliance of such manufacturing facilities would be significant.

In addition, the manufacturing process for any products that we may develop is subject to FDA, EMA, and comparable foreign regulatory authority approval processes and continuous oversight, and we will need to contract with manufacturers who can meet all applicable FDA, EMA and foreign regulatory authority requirements, including complying with cGMPs on an ongoing basis. Although our agreements with our CDMOs require them to perform according to certain cGMP requirements such as those relating to quality control, quality assurance and qualified personnel, we cannot control the ability of our CDMOs to implement and maintain these standards. If we or our third-party manufacturers are unable to reliably produce products to specifications acceptable to the FDA, EMA or other comparable foreign regulatory authorities or maintain a compliance status acceptable to the FDA, EMA, or other comparable foreign regulatory authorities, we may not obtain or maintain the approvals we need to commercialize such products. Even if we obtain regulatory approval for any of our product candidates, there is no assurance that either we or our CDMOs will be able to manufacture the approved product to specifications acceptable to the FDA, EMA, or other comparable foreign regulatory authorities, to produce it in sufficient quantities to meet the requirements for the potential launch of the product, or to meet potential future demand. Any of these challenges could delay completion of clinical trials, require bridging clinical trials or the repetition of one or more clinical trials, increase clinical trial costs, delay approval of our product candidates, impair commercialization efforts, increase our cost of goods and have an adverse effect on our business, financial condition, results of operations and prospects.

In order to produce sufficient quantities to meet the demand for clinical trials and, if approved, subsequent commercialization of our product candidates that we may develop, our third-party manufacturers will be required to increase their production and optimize their manufacturing processes while maintaining the quality of the product. The transition to larger scale production could prove difficult. In addition, if our third-party manufacturers are not able to optimize their manufacturing processes to increase the product yield for our product candidates, or if they are unable to produce increased amounts of our product candidates while maintaining the quality of the product, then we may not be able to meet the demands of clinical trials or market demands, which could decrease our ability to generate profits and have a material adverse impact on our business and results of operation.

We rely on our CDMOs to purchase from third-party suppliers the materials necessary to produce our product candidates for our clinical trials. We do not have, nor do we expect to enter into, any agreements for the commercial production of these raw materials, and we do not expect to have any control over the process or timing of our CDMOs’ acquisition of raw materials needed to produce our product candidates. Furthermore, we currently purchase the vaporization device with which we administer GH001 from a single third-party manufacturer, Storz & Bickel, Tuttlingen. We do not have a commercial supply agreement with such third-party manufacturer. Any significant delay in the supply of a product candidate, the raw material components thereof or any device necessary to administer our products for an ongoing clinical trial due to a manufacturer’s need to replace a third-party supplier of raw materials or medical devices could considerably delay completion of our clinical trials, product testing and potential regulatory approval of our product candidates. Additionally, if our future manufacturers or we are unable to purchase these raw materials to commercially produce any of our product candidates that gains regulatory approvals, or if we are unable to purchase or manufacture medical devices with which we administer any of our product candidates, the commercial launch of our product candidates would be delayed or there would be a shortage in supply, which would impair our ability to generate revenues from the sale of our product candidates.

Furthermore, for those third-party suppliers who are our sole source of supply of certain materials, we may not have arrangements in place for a redundant or second-source supply of any such materials or medical devices in the event any of our current suppliers cease their operations for any reason. Establishing additional or replacement suppliers for the raw materials used in our product candidates or medical devices used to administer our product candidates, if required, may not be accomplished quickly. If we are able to find a replacement supplier, such replacement supplier would need to be qualified and may require additional regulatory inspection or approval, which could result in further delay.

We are currently seeking and may continue to seek third-party collaborators for the research, development and commercialization of certain of the product candidates we may develop. Our likely collaborators include large and mid-size pharmaceutical companies, regional and national pharmaceutical companies, biotechnology companies and academic institutions. If we enter into any such arrangements with any third parties, we will likely have shared or limited control over the amount and timing of resources that our collaborators dedicate to the development or potential commercialization of any product candidates we may seek to develop with them. Our ability to generate revenue from these arrangements with commercial entities will depend on our collaborators’ abilities to successfully perform the functions assigned to them in these arrangements. We cannot predict the success of any collaboration that we enter into.

Collaborations involving our research programs, or any product candidates we may develop, pose the following risks to us:

We may face significant competition in seeking appropriate collaborations. Recent business combinations among biotechnology and pharmaceutical companies have resulted in a reduced number of potential collaborators. In addition, the negotiation process is time-consuming and complex, and we may not be able to negotiate collaborations on a timely basis, on acceptable terms, or at all. If we are unable to do so, we may have to curtail the development of the product candidate for which we are seeking to collaborate, reduce or delay its development program or one or more of our other development programs, delay its potential commercialization or reduce the scope of any sales or marketing activities, or increase our expenditures and undertake development or commercialization activities at our own expense. If we elect to increase our expenditures to fund development or commercialization activities on our own, we may need to obtain additional capital, which may not be available to us on acceptable terms or at all. If we do not have sufficient funds, we may not be able to further develop product candidates or bring them to market and generate product revenue.

If we enter into collaborations to develop and potentially commercialize any product candidates, we may not be able to realize the benefit of such transactions if we or our collaborator elects not to exercise the rights granted under the agreement or if we or our collaborator are unable to successfully integrate a product candidate into existing operations and company culture. The failure to develop and commercialize a product candidate pursuant to our agreements with our current or future collaborators could prevent us from receiving future payments under such agreements, which could negatively impact our revenues. In addition, if our agreement with any of our collaborators terminates, our access to technology and intellectual property licensed to us by that collaborator may be restricted or terminate entirely, which may delay our continued development of our product candidates utilizing the collaborator’s technology or intellectual property or require us to stop development of those product candidates completely. We may also find it more difficult to find a suitable replacement collaborator or attract new collaborators, and our development programs may be delayed or the perception of us in the business and financial communities could be adversely affected. Many of the risks relating to product development, regulatory approval, and commercialization described in this “Risk Factors” section also apply to the activities of our collaborators and any negative impact on our collaborators may adversely affect us.

We may acquire additional businesses or products, form strategic alliances or create joint ventures with third parties that we believe will complement or augment our existing business. If we acquire businesses with promising markets or technologies, we may not be able to realize the benefit of acquiring such businesses if we are unable to successfully integrate them with our existing operations and company culture. We may encounter numerous difficulties in developing, manufacturing and marketing any new products resulting from a strategic alliance or acquisition that delay or prevent us from realizing their expected benefits or enhancing our business. We cannot assure that, following any such acquisition, we will achieve the expected synergies to justify the transaction.

If a pandemic, epidemic or outbreak of an infectious disease occurs in Ireland or worldwide our business may be adversely affected. In December 2019, a novel strain of coronavirus named SARS-CoV-2 was

identified in Wuhan, China. This virus continues to spread globally, including in Ireland and the disease it causes, COVID-19, has been declared a pandemic by the World Health Organization, or WHO. The COVID-19 pandemic has impacted the global economy and may impact our operations, including the potential interruption of our clinical trial activities, regulatory reviews and our supply chain. For example, the COVID-19 pandemic may delay enrollment in our clinical trials due to prioritization of hospital resources toward the outbreak or other factors, and some patients may be unwilling to enroll in our trials or be unable to comply with clinical trial protocols if quarantines impede patient movement or interrupt healthcare services, which would delay our ability to conduct clinical trials or release clinical trial results and could delay our ability to obtain regulatory approval and commercialize our product candidates. Furthermore, the spread of the virus may affect the operations of key governmental agencies, such as the FDA, EMA or other comparable foreign regulatory authorities, which may delay the development or approval process for our product candidates.

The spread of an infectious disease, including COVID-19, may also result in the inability of our suppliers to deliver components or raw materials on a timely basis or at all. In addition, hospitals may reduce staffing and reduce or postpone certain treatments in response to the spread of an infectious disease. Such events may result in a period of business disruption, and in reduced operations, or doctors and medical providers may be unwilling to participate in our clinical trials, any of which could materially affect our business, financial condition and results of operations. For example, due to local restrictions in the Netherlands, we were forced take a three-month break in patient recruitment in our ongoing clinical trial in patients with TRD in 2020. We continue to closely monitor the COVID-19 pandemic as we evolve our business continuity plans, clinical development plans and response strategy. The extent to which the COVID-19 pandemic impacts our business will depend on future developments, which are highly uncertain and cannot be predicted, including new information which may emerge concerning the severity of the novel coronavirus and the actions to contain the coronavirus or treat its impact, among others. At present, we are not experiencing significant impact or delays from the COVID-19 pandemic on our business, operations and, if approved, commercialization plans. In addition, we have taken steps to mitigate against COVID-19 pandemic-related delays, and may take additional measures, intended to help minimize the risk of the virus to our employees, including temporarily requiring all employees to work remotely, suspending all non-essential travel worldwide for our employees, and discouraging employee attendance at industry events and in-person work-related meetings, which could negatively affect our business. In particular, our remote work arrangements for employees, coupled with stay-at-home orders and quarantines, pose challenges for those employees and our IT systems, and extended periods of remote work arrangements could strain our business continuity plans, introduce operational risk, including cybersecurity and IT systems management risks. Finally, an ongoing pandemic may also cause the risks associated with our industry and business described herein and in our public filings to become more significant.

A significant outbreak of other infectious diseases in the future also could result in a widespread health crisis that could adversely affect the economies and financial markets worldwide, resulting in an economic downturn that could impact our business, financial condition and results of operations.

Our success depends, and will likely continue to depend, upon our ability to hire, retain the services of our current executive officers, principal consultants and others. The loss of their services might impede the achievement of our research, development and commercialization objectives. We do not maintain “key person” insurance for any of our executives or other employees.

Our ability to compete in the biotechnology and pharmaceuticals industries depends upon our ability to attract and retain highly qualified managerial, scientific and medical personnel. Our industry has experienced a high rate of turnover of management personnel in recent years. Replacing executive officers or other key employees may be difficult and may take an extended period of time because of the limited number of individuals in our industry with the breadth of skills and experience required to develop, gain regulatory approval of and commercialize products successfully.

Competition to hire from this limited pool is intense, and we may be unable to hire, train, retain or motivate these additional key employees on acceptable terms given the competition among numerous pharmaceutical and biotechnology companies for similar personnel. We also experience competition for the hiring of scientific and clinical personnel from universities and research institutions.

We rely on consultants and advisors, including scientific and clinical advisors, to assist us in formulating our research and development and commercialization strategies. Our consultants and advisors may be employed by other entities and may have commitments under consulting or advisory contracts with those entities that may limit their availability to us. If we are unable to continue to attract and retain highly qualified personnel, our ability to develop and commercialize our product candidates will be limited.

As of May 31, 2021, we had eight employees and a large part of our development efforts remains outsourced to consultants, CMOs and CROs, aiming to optimize cash utilization and to manage and operate our business in a highly efficient manner. We cannot ensure that we will be able to hire and/or retain adequate staffing levels to develop GH001 and GH002 or other potential product candidates, or to run our operations and/or to accomplish all of the objectives that we otherwise would seek to accomplish.

We are exposed to the risk that our employees, independent contractors, consultants, collaborators and CROs may engage in fraudulent conduct or other illegal activity. Misconduct by those parties could include intentional, reckless and/or negligent conduct or disclosure of unauthorized activities to us that violates:

Activities subject to these laws also involve the improper use or misrepresentation of information obtained in the course of clinical trials, creating fraudulent data in our nonclinical studies or clinical trials or illegal misappropriation of product materials, which could result in regulatory sanctions and serious harm to our reputation. It is not always possible to identify and deter misconduct, and the precautions we take to detect and prevent this kind of activity may not be effective in controlling unknown or unmanaged risks or losses or in protecting us from governmental investigations or other actions or lawsuits stemming from a failure to be in compliance with such laws, standards or regulations. Additionally, we are subject to the risk that a person or government could allege such fraud or other misconduct, even if none occurred. If any such actions are instituted against us, and we are not successful in defending ourselves or asserting our rights, those actions could have a significant impact on our business and results of operations, including the imposition of civil, criminal and administrative penalties, damages, monetary fines, disgorgement, integrity oversight and reporting obligations, possible exclusion from participation in the United States in Medicare, Medicaid and other federal healthcare programs, contractual damages, reputational harm, diminished profits and future earnings and curtailment of our operations, any of which could have a material adverse effect on our ability to operate our business and our results of operations.

We expect to experience significant growth in the number of our employees and the scope of our operations, particularly in the areas of regulatory affairs and sales, marketing and distribution, as well as to support our public company operations. To manage these growth activities, we must continue to implement and improve our managerial, operational and financial systems, expand our facilities and continue to recruit and train additional qualified personnel. Our management may need to devote a significant amount of its attention to managing these growth activities. Moreover, our expected growth could require us to relocate to a different geographic area of Ireland. Due to our limited financial resources and the limited experience of our management team in managing a company with such anticipated growth, we may not be able to effectively manage the expansion or relocation of our operations, retain key employees, or identify, recruit and train additional qualified personnel. Our inability to manage the expansion or relocation of our operations effectively may result in weaknesses in our infrastructure, give rise to operational mistakes, loss of business opportunities, loss of employees and reduced productivity among remaining employees. Our expected growth could also require significant capital expenditures and may divert financial resources from other projects, such as the development of existing and additional product candidates. If we are unable to effectively manage our expected growth, our expenses may increase more than expected, our ability to generate revenues could be reduced and we may not be able to implement our business strategy, including the successful commercialization of our product candidates.

Our business is subject to risks associated with conducting business internationally. Accordingly, our future results could be harmed by a variety of factors, including:

These and other risks associated with our planned international operations may materially adversely affect our ability to attain profitable operations.

We, our collaborators, our CROs, third-party logistics and service providers, distributors, suppliers and other contractors and consultants utilize information technology, or IT, systems and networks to process, transmit and store electronic information in connection with our business activities. If our privacy, data protection, or information security measures (or those of any third parties that handle our sensitive information) are inadequate or are breached as a result of third-party action, employee or contractor error, malfeasance, malware, system error, software bugs or defects in our products, trickery, process failure or otherwise, third parties gaining access to employee accounts using stolen or inferred credentials, computer malware, viruses, spamming, phishing attacks or other means, and deliberate attacks and attempts to gain unauthorized access to computer systems and networks, and, as a result, there is improper disclosure of, or someone obtains unauthorized access to sensitive information, including personally identifiable information or protected health information, or if we suffer a ransomware or advanced persistent threat attack, or if any of the foregoing is reported or perceived to have occurred, our reputation and business could be damaged, we could incur significant costs associated with remediation and the implementation of additional security measures, we may incur significant liability and financial loss, and be subject to regulatory scrutiny, investigations, proceedings, lawsuits and penalties. While we have not experienced any such system failure, accident or security breach to date, if such an event were to occur and cause interruptions in our operations, it could result in a material disruption of our drug development programs. These threats pose a risk to the security of our, our collaborators’, our CROs’, third-party logistics and service providers’, distributors’, suppliers’ and other contractors’ and consultants’ systems and networks, and the confidentiality, availability and integrity of our data. There can be no assurance that we will be successful in preventing cyber-attacks or successfully mitigating their effects. Similarly, there can be no assurance that our collaborators, CROs, third-party logistics providers, distributors and other contractors and consultants will be successful in protecting our clinical and other data that is stored on their systems. Any cyber-attack, data breach, inaccessibility or destruction or loss of data could result in a violation of applicable U.S. and international privacy, data protection and other laws, and subject us to litigation and governmental investigations and proceedings by federal, state and local regulatory entities in the United States and by international regulatory entities, resulting in exposure to material civil and/or criminal liability. Further, our general liability insurance and corporate risk program may not cover all potential claims to which we are exposed and may not be adequate to indemnify us for all liability that may be imposed; and could have a material adverse effect on our business and prospects. For example, the loss of clinical trial data from completed, ongoing or planned clinical trials for any of our product candidates could result in delays in our development and regulatory approval efforts and significantly increase our costs to recover or reproduce the data. In addition, we may suffer reputational harm or face litigation or adverse regulatory action as a result of cyber-attacks or other data security breaches and may incur significant additional expense to implement further data protection measures.

This offering constitutes our initial public offering of ordinary shares, and no public market has previously existed for our ordinary shares. We have applied to list our ordinary shares on Nasdaq, and we expect our ordinary shares to be quoted on Nasdaq, subject to completion of customary procedures in the United States. Any delay in the commencement of trading of our ordinary shares on Nasdaq would impair the liquidity of the market for our ordinary shares and make it more difficult for holders to sell their ordinary shares.

Even if our ordinary shares are listed and quoted on Nasdaq, there is a risk that an active trading market for our ordinary shares may not develop or be sustained after this offering is completed. The initial offering price was determined by negotiations among the lead underwriters and us. Among the factors considered in determining the initial offering price will be the following:

Following the offering, our ordinary shares may not trade at a price equal to or greater than the initial offering price. The initial offering price may not be indicative of the market price of our ordinary shares after the offering. In the absence of an active trading market for our ordinary shares, investors may not be able to sell their ordinary shares at or above the initial offering price or at the time that they would like to sell.

The price of the securities of publicly traded emerging pharmaceutical and drug discovery and development companies has been highly volatile and is likely to remain highly volatile in the future. As a result of this volatility, you may not be able to sell your ordinary shares at or above the initial public offering price. The market price of our ordinary shares may fluctuate significantly due to a variety of factors, including the following:

These and other market and industry factors may cause the market price and demand for our securities to fluctuate substantially, regardless of our actual operating performance, which may limit or prevent investors from readily selling their ordinary shares and may otherwise negatively affect the liquidity of our ordinary shares. In addition, the stock market in general, and pharmaceutical companies in particular, have experienced extreme price and volume fluctuations that have often been unrelated or disproportionate to the operating performance of these companies, including as a result of the COVID-19 pandemic.

Upon the completion of this offering, our officers, directors, 5% holders and their affiliates will represent beneficial ownership, in the aggregate, of approximately   % of our total outstanding ordinary shares, including   % held by    (exclusive of any potential shares that may be purchased as part of this offering). As a result, these parties may be able to determine all matters requiring shareholder approval. For example, these shareholders may be able to exert control over our business, including significant corporate actions such as mergers, schemes of arrangement, sales of substantially all of our assets, and election, re-election and removal of directors. This may prevent or discourage unsolicited acquisition proposals or offers for our ordinary shares, or other such changes in control, that you may feel are in your best interest. The interests of this group of shareholders may not always coincide with your interests or the interests of other shareholders and they may act in a manner that advances their best interests and not necessarily those who purchase ordinary shares in this offering, including seeking a premium value for their ordinary shares, and might affect the prevailing market price for our ordinary shares.

For more information regarding our principal shareholders and their affiliated entities, see “Related Party Transactions” and “Principal Stockholders.”

To the extent our existing shareholders who are our affiliates or their affiliated entities participate in this offering, such purchases would reduce the non-affiliate public float of our ordinary shares after this offering, which is the number of ordinary shares that are not held by our officers, directors and affiliated shareholders. A reduction in the public float could reduce the number of ordinary shares that can be traded at any given time, which could adversely impact the liquidity of our ordinary shares and depress the price at which you may be able to sell ordinary shares purchased in this offering.

We have never declared or paid cash dividends on our ordinary shares and do not anticipate paying any dividends on our ordinary shares in the foreseeable future. Any determination to pay dividends in the future will be at the sole discretion of our board of directors after considering our financial condition, results of operations, capital requirements, contractual restrictions, general business conditions and other factors our board of directors deems relevant, and subject to compliance with applicable laws, including the Irish Companies Act 2014 (as amended), referred to herein as the Irish Companies Act, which requires Irish companies to have distributable reserves available for distribution equal to or greater than the amount of the proposed dividend. Distributable reserves are the accumulated realized profits of the company that have not previously been utilized in a distribution or capitalization less accumulated realized losses that have not previously been written off in a reduction or reorganization of capital. Unless the company creates sufficient distributable reserves from its business activities, the creation of such distributable reserves would involve a reduction of the company’s share premium account or other

undenominated capital account, which would require the approval of (i) 75% of our shareholders present and voting at a shareholder meeting, and (ii) the Irish High Court. In the event that we do not undertake a reduction of capital to create distributable reserves, no distributions by way of dividends, share repurchases or otherwise will be permitted under Irish law until such time as the company has created sufficient distributable reserves from its business activities. The determination as to whether or not the company has sufficient distributable reserves to fund a dividend must be made by reference to “relevant accounts” of the company. The “relevant accounts” are either the last set of unconsolidated annual audited financial statements or unaudited financial statements prepared in accordance with the Irish Companies Act, which give a “true and fair view” of the company’s unconsolidated financial position in accordance with accepted accounting practice in Ireland.

We intend to retain earnings, if any, for use in our business and do not anticipate paying any cash dividends in the foreseeable future. As a result, capital appreciation, if any, on our ordinary shares will be your sole source of gains for the foreseeable future, and you will suffer a loss on your investment if you are unable to sell your ordinary shares at or above the initial public offering price. Any recommendation by our board of directors to pay dividends will depend on many factors, including our financial condition (including losses carried forward), results of operations, legal requirements and other factors. We are unlikely to pay dividends or other distributions in the foreseeable future. If the price of our ordinary shares declines before we pay dividends, you will incur a loss on your investment, without the likelihood that this loss will be offset in part or at all by potential future cash dividends. Investors seeking cash dividends should not purchase our ordinary shares in this offering.

In certain circumstances, as an Irish tax resident company, we will be required to deduct Irish dividend withholding tax (currently at the rate of 25%) from dividends paid to our shareholders. Shareholders that are resident in the United States, EU countries (other than Ireland) or other countries with which Ireland has signed a tax treaty (whether the treaty has been ratified or not) generally should not be subject to Irish dividend withholding tax so long as the shareholder has provided its broker, for onward transmission to our qualifying intermediary or other designated agent (in the case of shares held beneficially), or us or our transfer agent (in the case of shares held directly), with all the necessary documentation by the appropriate due date prior to payment of the dividend.

Our board of directors will have broad discretion in the application of the net proceeds from the offering and could spend the proceeds in ways that do not improve our results of operations or enhance the value of our ordinary shares. The failure by our board of directors to apply these funds effectively could result in financial losses that could have a material adverse effect on our business, cause the price of our ordinary shares to decline and delay the development of our GH001 and GH002 product candidates or any future product candidates. Pending their use, we may invest the net proceeds from the offering in a manner that does not produce income or that loses value.

The trading market of our ordinary shares depends in part on the research and reports that securities or industry analysts publish about us or our business. We do not have control over these analysts. We do not currently have research coverage, and there can be no assurance that analysts will cover us, or provide favorable coverage. If no or few securities or industry analysts cover our company, the trading price of our ordinary shares would be negatively impacted. If one or more of the analysts who covers us downgrades our ordinary shares or publishes incorrect or unfavorable research about our business, the

price of our ordinary shares would likely decline. If one or more of these analysts ceases coverage of our company or fails to publish reports on us regularly, or downgrades our ordinary shares, demand for our ordinary shares could decrease, which could cause the price of our ordinary shares or trading volume to decline.

If our existing shareholders sell, or indicate an intent to sell, substantial amounts of ordinary shares in the public market after the 180-day contractual lock-up and other legal restrictions on resale discussed elsewhere in this prospectus lapse, the trading price of our ordinary shares could decline significantly and could decline below the public offering price. Upon completion of this offering, we will have outstanding    ordinary shares,    of which are subject to the 180-day contractual lock-up referred to above. Cowen and Company, LLC and Stifel, Nicolaus & Company, Incorporated may permit us, our directors and members of our executive committee and shareholders to sell ordinary shares prior to the expiration of the lock-up agreements. See “Underwriting.”

After the lock-up agreements pertaining to the offering expire, and based on the number of ordinary shares outstanding upon completion of this offering,   additional ordinary shares will be eligible for sale in the public market, subject to volume limitations under Rule 144 under the Securities Act of 1933, as amended, or the Securities Act, in the case of our affiliates.

Following the offering, we intend to file one or more registration statements with the SEC covering ordinary shares available for future issuance under our equity incentive plans. Upon effectiveness of such registration statements, any ordinary shares subsequently issued under such plans will be eligible for sale in the public market, except to the extent that they are restricted by the lock-up agreements referred to above and subject to compliance with Rule 144 of the Securities Act, or Rule 144, in the case of our affiliates. We will also enter into the Registration Rights Agreement pursuant to which we will grant demand, short form and piggyback registration rights to our existing shareholders. Sales of a large number of the ordinary shares issued under these plans in the public market could have an adverse effect on the market price of our ordinary shares. These sales might also make it more difficult for us to issue or sell equity or equity-related securities in the future at a time and a price that we deem appropriate. See the section of this prospectus titled “Shares Eligible for Future Sale” for a more detailed description of sales that may occur in the future. If these additional ordinary shares are sold, or if it is perceived that they will be sold, in the public market, the trading price of our ordinary shares could decline substantially.

If you purchase our ordinary shares in this offering, you will experience substantial and immediate dilution of $   per ordinary share in the net tangible book value after giving effect to the offering at an assumed public offering price of $   per ordinary share, the midpoint of the estimated price range set forth on the cover page of this prospectus, because the price that you pay will be substantially greater than the net tangible book value per ordinary share that you acquire. This dilution is due in large part to the fact that our earlier investors paid substantially less than the public offering price when they purchased their ordinary shares. You will experience additional dilution if we issue additional ordinary shares below the public offering price. For a further description of the dilution that you will experience immediately after the offering, see the section of this prospectus titled “Dilution.”

As a matter of Irish law, holders of our ordinary shares will have a preemption right with respect to any issuance of our ordinary shares for cash consideration or the granting of rights to subscribe for our ordinary shares for cash consideration, unless such preemption right is disapplied, in whole or in part,

either in the Constitution or by resolution of our shareholders at a general meeting of shareholders or otherwise. However, we have opted out of these preemption rights in the Constitution as permitted under Irish company law (for a period of five years). Thus, our board of directors will be permitted to issue up to all of our authorized but unissued share capital on a non-preemptive basis for cash consideration at any stage during the period of five years after the date of adoption of the Constitution. In addition, even if the disapplication of preemption rights contained in the Constitution expires (and is not renewed by shareholders at a general meeting) or is terminated by our shareholders in a general meeting, due to laws and regulations in certain jurisdictions outside Ireland, shareholders in such jurisdictions may not be able to exercise their preemption rights unless we take action to register or otherwise qualify the rights offering under the laws of that jurisdiction. For example, in the United States, U.S. holders of our ordinary shares may not be able to exercise preemption rights unless a registration statement under the Securities Act is declared effective with respect to our ordinary shares issuable upon exercise of such rights or an exemption from the U.S. registration requirements is available. If shareholders in such jurisdictions are unable to exercise their preemption rights, their ownership interest would be diluted. Any future issuance of shares or debt instruments convertible into shares where preemption rights are not available or are excluded would result in the dilution of existing shareholders and reduce the earnings per share, which could have a material adverse effect on the price of shares.

Historically, securities class action litigation has often been brought against a company following a decline in the market price of its securities. This risk is especially relevant for us because pharmaceutical and biopharmaceutical companies have experienced significant share price volatility in recent years. If we were to be sued, it could result in substantial costs and a diversion of management’s attention and resources, which could harm the trading price of our ordinary shares.

Transfers of ordinary shares effected by means of the transfer of book entry interests in the Depository Trust Company, or DTC, should not be subject to Irish stamp duty where ordinary shares are traded through DTC, either directly or through brokers that hold such shares on behalf of customers through DTC. However, if you hold your ordinary shares as of record rather than beneficially through DTC, any transfer of ordinary shares could be subject to Irish stamp duty (currently at the rate of 1% of the higher of the price paid or the market value of the shares acquired). Payment of Irish stamp duty is generally a legal obligation of the transferee. The potential for stamp duty to arise could adversely affect the price of our ordinary shares. For more information, see “Tax Considerations—Material Irish Tax Consequences—Stamp Duty.”

Our Constitution to be effective in connection with this offering will provide that the courts of Ireland will be the exclusive forum for resolving all shareholder complaints other than shareholder complaints asserting a cause of action arising under the Securities Act and the Exchange Act, and that the U.S. federal district courts will be the exclusive forum for resolving any shareholder complaint asserting a cause of action arising under the Securities Act and the Exchange Act, including applicable claims arising out of this offering. This choice of forum provision may limit a shareholder’s ability to bring a claim in a judicial forum that it finds favorable for disputes with us or our directors, officers or other employees, which may discourage such lawsuits. The enforceability of similar exclusive forum provisions (including exclusive federal forum provisions for actions, suits or proceedings asserting a cause of action arising under the Securities Act) in other companies’ organizational documents has been challenged in legal

proceedings, and there is uncertainty as to whether courts would enforce the exclusive forum provisions in our Constitution. Additionally, our shareholders cannot waive compliance with the federal securities laws and the rules and regulations thereunder. If a court were to find either choice of forum provision contained in our Constitution to be inapplicable or unenforceable in an action, we may incur additional costs associated with resolving such action in other jurisdictions, which could adversely affect our results of operations and financial condition.

We are incorporated and have our registered office in, and are currently existing under the laws of, Ireland. In addition, certain members of our board of directors and senior management are nonresidents of the United States, and all or a substantial portion of our assets and the assets of such persons are located outside the United States. As a result, it may not be possible to serve process on such persons or us in the United States or to enforce judgments obtained in U.S. courts against them or us based on civil liability provisions of the securities laws of the United States. As a result, it may not be possible for investors to effect service of process within the United States upon such persons or to enforce judgments obtained in U.S. courts against them or us, including judgments predicated upon the civil liability provisions of the U.S. federal securities laws.

The United States and Ireland do not currently have a treaty providing for recognition and enforcement of judgments (other than arbitration awards) in civil and commercial matters. Consequently, a final judgment for payment given by a court in the United States, whether or not predicated solely upon U.S. securities laws, would not automatically be recognized or enforceable in Ireland. In addition, uncertainty exists as to whether Irish courts would entertain original actions brought in Ireland against us or our directors or senior management predicated upon the securities laws of the United States or any state in the United States. Any final and conclusive monetary judgment for a definite sum obtained against us in U.S. courts would be treated by Irish courts as a cause of action in itself and sued upon as a debt at common law so that no retrial of the issues would be necessary, provided that certain requirements are met. Whether these requirements are met in respect of a judgment based upon the civil liability provisions of the U.S. securities laws, including whether the award of monetary damages under such laws would constitute a penalty is an issue subject to determination by the court making such decision. If an Irish court gives judgment for the sum payable under a U.S. judgment, the Irish judgment will be enforceable by methods generally available for this purpose. These methods generally permit the Irish court discretion to prescribe the manner of enforcement.

As a result, U.S. investors may not be able to enforce against us or our senior management, board of directors or certain experts named herein who are residents of Ireland or countries other than the United States any judgments obtained in U.S. courts in civil and commercial matters, including judgments under the U.S. federal securities laws.

Under the Internal Revenue Code of 1986, as amended, or the Code, we will be a passive foreign investment company, or PFIC, for any taxable year in which, after the application of certain look-through rules with respect to our subsidiaries, either (1) 75% or more of our gross income consists of “passive income;” or (2) 50% or more of the average quarterly value of our assets consists of assets that produce, or are held for the production of, “passive income.” Passive income generally includes dividends, interest, certain non-active rents and royalties, and capital gains. Based on our current operations, income, assets and certain estimates and projections, including as to the relative values of our assets, including goodwill, which is based on the expected price of our ordinary shares, we do not expect to be a PFIC for our 2021 taxable year. In addition, whether we will be a PFIC in 2021 or any future year is uncertain because, among other things, (1) we will hold a substantial amount of cash following this offering, which is generally categorized as a passive asset; and (2) our PFIC status for any taxable year will depend on the composition of our income and assets and the value of our assets from time to time (which may be

determined, in part, by reference to the market price of our ordinary shares, which could be volatile). Accordingly, there can be no assurance that we will not be a PFIC for any taxable year.

If we are a PFIC for any taxable year during which a U.S. investor holds ordinary shares, we generally would continue to be treated as a PFIC with respect to that U.S. investor for all succeeding years during which the U.S. investor holds ordinary shares, even if we ceased to meet the threshold requirements for PFIC status. Such a U.S. investor may be subject to adverse U.S. federal income tax consequences, including (1) the treatment of all or a portion of any gain on disposition as ordinary income; (2) the application of a deferred interest charge on such gain and the receipt of certain dividends; and (3) compliance with certain reporting requirements. A “mark-to-market” election may be available that will alter the consequences of PFIC status if our ordinary shares are regularly traded on a qualified exchange. For further discussion, see “Tax Considerations—Material U.S. Federal Income Tax Consequences for U.S. Holders.”

We are an “emerging growth company,” as defined in the JOBS Act, and we intend to take advantage of certain exemptions from various reporting requirements that are applicable to other public companies that are not “emerging growth companies,” including not being required to comply with the auditor attestation requirements of Section 404(b) of the Sarbanes-Oxley Act and exemptions from the requirements of holding a nonbinding advisory vote on executive compensation and shareholder approval of any golden parachute payments not previously approved. We cannot predict if investors will find our ordinary shares less attractive because we may rely on these exemptions. If some investors find our ordinary shares less attractive as a result, there may be a less active trading market for our ordinary shares and the price of our ordinary shares may be more volatile. We may take advantage of these reporting exemptions until we are no longer an emerging growth company. We will remain an emerging growth company until the earliest of (1) the last day of the fiscal year (i) in which we have total annual gross revenue of $1.07 billion; (ii) following the fifth anniversary of the date of the completion of the offering; or (iii) in which we are deemed to be a “large accelerated filer,” which requires the market value of our ordinary shares that is held by non-affiliates to exceed $700 million as of the prior June 30th, and (2) the date on which we have issued more than $1 billion in nonconvertible debt during the previous three-year period. We cannot predict if investors will find our ordinary shares less attractive because we rely on these exemptions. If some investors find our ordinary shares less attractive as a result, there may be a less active trading market for our ordinary shares and the price of our ordinary shares may be more volatile.

As a foreign private issuer, we are permitted to follow certain home country corporate governance practices as opposed to those requirements that would otherwise be required by Nasdaq for domestic U.S. issuers. Following our home country governance practices allows us to follow Irish corporate law and the Irish Companies Act with regard to certain corporate governance matters as opposed to the requirements that would otherwise apply to U.S. companies listed on Nasdaq may provide less protection to our shareholders than what is accorded to investors under Nasdaq rules applicable to domestic U.S. issuers.

As a foreign private issuer, we are exempt from the rules and regulations under the Exchange Act related to the furnishing and content of proxy statements. Our officers, directors and principal shareholders are also exempt from the reporting and short-swing profit recovery provisions contained in Section 16 of the Exchange Act. In addition, we are not required under the Exchange Act to file reports and financial statements with the SEC as frequently or as promptly as U.S. domestic companies whose

securities are registered under the Exchange Act and we are exempt from filing quarterly reports with the SEC under the Exchange Act. Moreover, we are not required to comply with Regulation FD, which restricts the selective disclosure of material information, although we have voluntarily adopted a corporate disclosure policy substantially similar to Regulation FD. These exemptions and leniencies will reduce the frequency and scope of information and protections to which you may otherwise have been eligible in relation to a U.S. domestic issuer.

In accordance with our Nasdaq listing, our audit and risk committee is required to comply with the provisions of Section 301 of the Sarbanes-Oxley Act, and Rule 10A-3 of the Exchange Act. Because we are a foreign private issuer, however, our audit and risk committee is not subject to additional Nasdaq requirements applicable to listed U.S. companies, including an affirmative determination that all members of the audit and risk committee are “independent,” using more stringent criteria than those applicable to us as a foreign private issuer. Furthermore, Nasdaq’s corporate governance rules require listed U.S. companies to, among other things, seek shareholder approval for the implementation of certain equity compensation plans and issuances of ordinary shares, which we are not required to follow as a foreign private issuer. Therefore, our shareholders may be afforded less protection than they otherwise would have under corporate governance listing standards applicable to U.S. domestic issuers.

While we currently qualify as a foreign private issuer, the determination of foreign private issuer status is made annually on the last business day of an issuer’s most recently completed second fiscal quarter and, accordingly, the next determination will be made with respect to us on June 30, 2021.

In the future, we would lose our foreign private issuer status if we were to fail to meet the requirements necessary to maintain our foreign private issuer status as of the relevant determination date. For example, if more than 50% of our securities are held by U.S. residents and more than 50% of the members of our executive committee or members of our board of directors are residents or citizens of the United States, we could lose our foreign private issuer status.

The regulatory and compliance costs to us under U.S. securities laws as a U.S. domestic issuer may be significantly more than costs we incur as a foreign private issuer. If we are not a foreign private issuer, we will be required to file periodic reports and registration statements on U.S. domestic issuer forms with the SEC, which are more detailed and extensive in certain respects than the forms available to a foreign private issuer. In addition, we may lose our ability to rely upon exemptions from certain corporate governance requirements on U.S. stock exchanges that are available to foreign private issuers such as the ones described above and exemptions from procedural requirements related to the solicitation of proxies.

As a publicly traded company, we will incur significant additional legal, accounting and other expenses compared to historical levels. In addition, new and changing laws, regulations and standards relating to corporate governance and public disclosure, including the Dodd-Frank Wall Street Reform and Consumer Protection Act and the rules and regulations promulgated and to be promulgated thereunder, as well as under the Sarbanes-Oxley Act, the JOBS Act and the rules and regulations of the SEC and Nasdaq, have created uncertainty for public companies and increased our costs and time that our board of directors and management must devote to complying with these rules and regulations. We expect these rules and regulations to increase our legal and financial compliance costs substantially and lead to diversion of management time and attention from revenue-generating activities.

You may have difficulties enforcing, in actions brought in courts in jurisdictions located outside the United States, judgments obtained in the U.S. courts under the U.S. securities laws. In particular, if you sought to bring proceedings in Ireland based on U.S. securities laws, the Irish court might consider:

It may not be possible to enforce court judgments obtained in the United States against us in Ireland based on the civil liability provisions of the U.S. federal or state securities laws. In addition, there is some uncertainty as to whether the courts of Ireland would recognize or enforce judgments of U.S. courts obtained against us or our directors or officers based on the civil liabilities provisions of the U.S. federal or state securities laws. We have been advised that the United States currently does not have a treaty with Ireland providing for the reciprocal recognition and enforcement of judgments in civil and commercial matters. Therefore, a final judgment for the payment of money rendered by any U.S. federal or state court based on civil liability, whether or not based solely on U.S. federal or state securities laws, would not automatically be enforceable in Ireland.

A judgment obtained against us will be enforced by the courts of Ireland only if the following general requirements are met:

A judgment can be final and conclusive even if it is subject to appeal or even if an appeal is pending. But where the effect of lodging an appeal under the applicable law is to stay execution of the judgment, it is possible that in the meantime the judgment may not be actionable in Ireland. It remains to be determined whether final judgment given in default of appearance is final and conclusive. Irish courts may also refuse to enforce a judgment of the U.S. courts which meets the above requirements for one of the following reasons:

As an Irish company, we are governed by the Irish Companies Act, which differs in some material respects from laws generally applicable to U.S. corporations and shareholders, including, among others, differences relating to interested director and officer transactions and shareholder lawsuits. Likewise, the duties of directors and officers of an Irish company generally are owed to the company only. Shareholders of Irish companies generally do not have a personal right of action against directors or officers of the

company and may exercise such rights of action on behalf of the company only in limited circumstances. Accordingly, holders of our securities may have more difficulty protecting their interests than would holders of securities of a corporation incorporated in a jurisdiction of the United States.

You should also be aware that Irish law does not allow for any form of legal proceedings directly equivalent to the class action available in the United States. For further information with respect to your rights as a shareholder, see “Description of Share Capital and Constitution.”

Under Irish law, our authorized share capital can be increased by an ordinary resolution of our shareholders and the directors may issue new ordinary or preferred shares up to a maximum amount equal to the authorized but unissued share capital, without shareholder approval, once authorized to do so by our Constitution or by an ordinary resolution of our shareholders. Additionally, subject to specified exceptions, Irish law grants statutory preemption rights to existing shareholders where shares are being issued for cash consideration but allows shareholders to disapply such statutory preemption rights either in our Constitution or by way of special resolution. Such disapplication can either be generally applicable or be in respect of a particular allotment of shares. Accordingly, our Constitution adopted on closing of this offering will contain, as permitted by Irish company law, provisions authorizing the board to issue new shares, and to disapply statutory preemption rights. The authorization of the directors to issue shares and the disapplication of statutory preemption rights must both be renewed by the shareholders at least every five years, and we cannot provide any assurance that these authorizations will always be approved, which could limit our ability to issue equity and thereby adversely affect the holders of our securities.

We believe these provisions, if implemented in compliance with applicable law, may provide some protection to holders of ordinary shares from coercive or otherwise unfair takeover tactics. These provisions are not intended to make us immune from takeovers. They will, however, apply even if some holders of ordinary shares consider an offer to be beneficial and could delay or prevent an acquisition that our board of directors determines is in the best interest of the holders of ordinary shares. Certain of these provisions may also prevent or discourage attempts to remove and replace incumbent directors.

In addition, mandatory provisions of Irish law could prevent or delay an acquisition of the Company by a third party. For example, Irish law does not permit shareholders of an Irish public limited company to take action by written consent with less than unanimous consent. In addition, an effort to acquire us may be subject to various provisions of Irish law relating to mandatory bids, voluntary bids, requirements to make a cash offer and minimum price requirements, as well as substantial acquisition rules and rules requiring the disclosure of interests in ordinary shares in certain circumstances.

Following the authorization for trading of our ordinary shares on Nasdaq, we became subject to the Irish Takeover Panel Act, 1997, Irish Takeover Rules 2013, or the Irish Takeover Rules. Under the Irish Takeover Rules, our board of directors is not permitted to take any action that might frustrate an offer for our ordinary shares once our board of directors has received an approach that may lead to an offer or has reason to believe that such an offer is or may be imminent, subject to certain exceptions. Potentially frustrating actions such as (i) the issue of shares, options, restricted share units or convertible securities, (ii) material acquisitions or disposals, (iii) entering into contracts other than in the ordinary course of business or (iv) any action, other than seeking alternative offers, which may result in frustration of an offer, are prohibited during the course of an offer or at any earlier time during which our board of directors has reason to believe an offer is or may be imminent. These provisions may give our board of directors less ability to control negotiations with hostile offerors than would be the case for a corporation incorporated in a jurisdiction of the United States.

Under the Irish Takeover Rules, if an acquisition of ordinary shares were to increase the aggregate holding of the acquirer and its concert parties to ordinary shares that represent 30% or more of the voting rights of the company, the acquirer and, in certain circumstances, its concert parties would be required (except with the consent of the Irish Takeover Panel) to make an offer for the outstanding ordinary shares at a price not less than the highest price paid for the ordinary shares by the acquirer or its concert parties during the previous 12 months. This requirement would also be triggered by an acquisition of ordinary shares by a person holding (together with its concert parties) ordinary shares that represent between 30% and 50% of the voting rights in the company if the effect of such acquisition were to increase that person’s percentage of the voting rights by 0.05% within a 12-month period. Following the authorization for trading of our ordinary shares on Nasdaq, under the Irish Takeover Rules, certain separate concert parties are presumed to be acting in concert. Our board of directors and their relevant family members, related trusts and “controlled companies” are presumed to be acting in concert with any corporate shareholder who holds 20% or more of our shares. The application of these presumptions may result in restrictions upon the ability of any of the concert parties and/or members of our board of directors to acquire more of our securities, including under the terms of any executive incentive arrangements. Following the listing of our ordinary shares on Nasdaq, we may consult with the Irish Takeover Panel with respect to the application of this presumption and the restrictions on the ability to acquire further securities, although we are unable to provide any assurance as to whether the Irish Takeover Panel will overrule this presumption. For a description of certain takeover provisions applicable to us, see the section titled “Description of Share Capital and Constitution—Irish Takeover Rules and Substantial Acquisition Rules.” Accordingly, the application of the Irish Takeover Rules may restrict the ability of certain of our shareholders and directors to acquire our ordinary shares.

Ensuring that we have adequate internal financial and accounting controls and procedures in place so that we can produce accurate financial statements on a timely basis is a costly and time-consuming effort that needs to be re-evaluated frequently. Our internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements in accordance with generally accepted accounting principles. In connection with this offering, we intend to begin the process of documenting, reviewing, and improving our internal controls and procedures for compliance with Section 404 of the Sarbanes-Oxley Act, which

will require annual management assessment of the effectiveness of our internal control over financial reporting. We have begun recruiting additional finance and accounting personnel with certain skill sets that we will need as an Irish public company listed in the United States.

Implementing any appropriate changes to our internal controls may distract our officers and employees from day-to-day business operations, entail substantial costs to modify our existing processes, and take significant time to complete. These changes may not, however, be effective in maintaining the adequacy of our internal controls, and any failure to maintain that adequacy, or consequent inability to produce accurate financial statements on a timely basis, could increase our operating costs and harm our business. In addition, investors’ perceptions that our internal controls are inadequate or that we are unable to produce accurate financial statements on a timely basis may harm the price of our ordinary shares.

Our management is responsible for establishing and maintaining adequate internal control over financial reporting. Internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements in accordance with generally accepted accounting principles, or GAAP. As a result of becoming a public company, we will be required, pursuant to Section 404 of the Sarbanes-Oxley Act, to furnish a report by our management on, among other things, the effectiveness of our internal control over financial reporting for the first fiscal year beginning after the effective date of the registration statement of which this prospectus is a part. This assessment will need to include disclosures of any material weaknesses identified by our management in our internal control over financial reporting. A “material weakness” is a deficiency, or a combination of deficiencies, in internal control over financial reporting such that there is a reasonable possibility that a material misstatement of our annual or interim financial statements will not be prevented or detected on a timely basis. We are in the very early stages of the costly and challenging process of planning the activities necessary to perform the evaluation needed to comply with Section 404 of the Sarbanes-Oxley Act.

In connection with the preparation of our financial statements for the years ended December 31, 2019 and 2020, we identified material weaknesses in our internal control over financial reporting. Specifically, we determined that we lack a sufficient number of trained professionals with an appropriate level of accounting knowledge, training and experience to: (a) design and maintain formal accounting policies, procedures and controls over the fair presentation of our financial statements; and (b) design and maintain controls over the preparation and review of account reconciliations, journal entries and financial statements, including maintaining appropriate segregation of duties.

These control deficiencies did not result in a material misstatement to the financial statements. However, each of these control deficiencies could result in a misstatement of our accounts or disclosures that would result in a material misstatement of our annual or interim financial statements that would not be prevented or detected, and accordingly, we determined that these control deficiencies constitute material weaknesses.

Prior to the completion of this offering, we have been a private company with limited accounting personnel to adequately execute our accounting processes and other supervisory resources with which to address our internal control over financial reporting. We are progressing with the activities necessary to implement the appropriate accounting policies, processes and controls required to comply with Section 404 of the Sarbanes-Oxley Act and are in the process of identifying the relevant individuals with the requisite expertise to assist in implementation activities designed to improve our internal control over financial reporting and remediate the control deficiencies that led to these material weaknesses, including hiring additional finance and accounting personnel and initiating design and implementation of our financial control environment. We cannot assure you that the measures we have taken to date, and actions we may take in the future, will be sufficient to remediate the control deficiencies that led to these

material weaknesses in our internal control over financial reporting nor that they will prevent or avoid potential future material weaknesses. We cannot assure you that all of our existing material weaknesses have been identified, or that we will not in the future identify additional material weaknesses.

If we are unsuccessful in building an appropriate accounting infrastructure, we may not be able to prepare and disclose, in a timely manner, our financial statements and other required disclosures, or comply with existing or new reporting requirements. Any failure to report our financial results on an accurate and timely basis could result in sanctions, lawsuits, delisting of our shares from Nasdaq or other adverse consequences that could materially harm our business. If we cannot provide reliable financial reports or prevent fraud, our business and results of operations could be harmed and investors could lose confidence in our reported financial information. Any of the foregoing occurrences, should they come to pass, could negatively impact the public perception of our company, which could have a negative impact on our share price. In addition, we may be required to incur additional costs in improving our internal control system and the hiring of additional personnel.

This prospectus contains statements that are, or may deemed to be, forward-looking statements. All statements other than statements of historical fact included in this prospectus, including statements regarding our future results of operations and financial position, business strategy, product candidates, research pipeline, ongoing and currently planned preclinical studies and clinical trials, regulatory submissions and approvals, research and development costs, timing and likelihood of success, as well as plans and objectives of management for future operations are forward-looking statements. Many of the forward-looking statements contained in this prospectus can be identified by the use of forward-looking words such as “may,” “anticipate,” “believe,” “could,” “expect,” “should,” “plan,” “intend,” “estimate,” “will,” “potential” and “ongoing,” among others.

Forward-looking statements appear in a number of places in this prospectus and include, but are not limited to, statements regarding our intent, belief or current expectations. Forward-looking statements are based on our management’s beliefs and assumptions and on information currently available to our management. Such statements are subject to risks and uncertainties, and actual results may differ materially from those expressed or implied in the forward-looking statements due to various factors, including, but not limited to, those identified under the section entitled “Risk Factors” in this prospectus. These risks and uncertainties include, among others, factors relating to:

These forward-looking statements speak only as of the date of this prospectus and are subject to a number of risks, uncertainties and assumptions described under the sections in this prospectus entitled “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and elsewhere in this prospectus. Because forward-looking statements are inherently subject to risks and uncertainties, some of which cannot be predicted or quantified and some of which are beyond our control, you should not rely on these forward-looking statements as predictions of future events. The events and circumstances reflected in our forward-looking statements may not be achieved or occur and actual results could differ materially from those projected in the forward-looking statements. Moreover, we operate in an evolving environment. New risk factors and uncertainties may emerge from time to time, and it is not possible for management to predict all risk factors and uncertainties. Except as required by applicable law, we do not plan to publicly update or revise any forward-looking statements contained herein, whether as a result of any new information, future events, changed circumstances or otherwise. The forward-looking statements contained in this prospectus are excluded from the safe harbor protection

provided by the Private Securities Litigation Reform Act of 1995 and Section 27A of the Securities Act, which does not extend to initial public offerings. You should read this prospectus and the documents that we have filed as exhibits to the registration statement, of which this prospectus is a part, completely and with the understanding that our actual future results may be materially different from what we expect. We qualify all of our forward-looking statements by these cautionary statements.

In addition, statements that “we believe” and similar statements reflect our beliefs and opinions on the relevant subject. These statements are based upon information available to us as of the date of this prospectus, and while we believe such information forms a reasonable basis for such statements, such information may be limited or incomplete, and our statements should not be read to indicate that we have conducted an exhaustive inquiry into, or review of, all potentially available relevant information. These statements are inherently uncertain and investors are cautioned not to unduly rely upon these statements.

We estimate that the net proceeds to us in this offering will be $    million, after deducting underwriting discounts and commissions and estimated offering expenses payable by us, based on an assumed initial public offering price of $    per share, which is the midpoint of the price range set forth on the cover page of this prospectus. If the underwriters exercise their option to purchase additional ordinary shares in full, we estimate that the net proceeds to us from this offering will be $    million, after deducting underwriting discounts and commissions and estimated offering expenses payable by us.

Each $1.00 increase or decrease in the assumed initial public offering price of $    per share, the midpoint of the price range set forth on the cover page of this prospectus, would increase or decrease the net proceeds to us from this offering by $    million, assuming that the number of ordinary shares offered by us, as set forth on the cover page of this prospectus, remains the same and after deducting underwriting discounts and commissions and estimated offering expenses payable by us. A 1,000,000 share increase or decrease in the number of ordinary shares offered by us would increase or decrease the net proceeds to us from this offering by approximately $    million, assuming that the initial public offering price per share remains the same, and after deducting underwriting discounts and commissions and estimated offering expenses payable by us.

We expect to use the net proceeds from this offering, together with our existing cash, as follows:

This expected use of net proceeds from this offering represents our intentions based upon our current plans and business conditions, which could change in the future as our plans and business conditions evolve. We cannot predict with certainty all of the particular uses for the net proceeds to be received upon the completion of this offering or the amounts that we will actually spend on the uses set forth above. Predicting the cost necessary to develop product candidates and commercialize approved products can be difficult and the amounts and timing of our actual expenditures may vary significantly depending on numerous factors, including the progress of our development, the status of and results from clinical trials, any collaborations that we may enter into with third parties for our therapeutic candidate and any unforeseen cash needs. Our management will retain broad discretion over the allocation of the net proceeds from this offering.

Based on our planned use of the net proceeds from this offering and our existing cash, including the net proceeds from the Series B Financing, we estimate that such funds will be sufficient to fund our operations and capital expenditure requirements through      , although there can be no assurance in that regard. We have based this estimate on assumptions that may prove to be wrong, and we could use our available capital resources sooner than we currently expect.

Our management will have broad discretion over the use of the net proceeds from this offering. The amounts and timing of our expenditures will depend upon numerous factors, including the results of our research and development efforts, the timing, cost and success of preclinical studies and any ongoing clinical trials or clinical trials we may commence in the future, the timing of regulatory submissions, our ability to obtain additional financing, the amount of cash obtained through our existing collaborations and future collaborations, if any, and any unforeseen cash needs.

Pending our use of proceeds from this offering, we plan to invest these net proceeds in a variety of capital preservation instruments, including short-term, interest bearing obligations and investment-grade instruments.

We have never declared or paid cash dividends on our share capital. We intend to retain all available funds and any future earnings, if any, to fund the development and expansion of our business and we do not anticipate paying any cash dividends in the foreseeable future. Any future determination related to dividend policy will be made at the discretion of our board of directors and will depend upon, among other factors, our results of operations, financial condition, capital requirements, contractual restrictions, business prospects and other factors our board of directors may deem relevant.

Under Irish law, among other things, we may only pay dividends if we have sufficient distributable reserves (on a non-consolidated basis), which are our accumulated realized profits that have not been previously distributed or capitalized, less our accumulated realized losses, so far as such losses have not been previously written off in a reduction or reorganization of capital. In addition, no distribution or dividend may be made if the net assets of GH Research PLC are not, or if making such distribution or dividend will cause the net assets of GH Research PLC to not be, equal to or in excess of the aggregate of GH Research PLC’s called up share capital plus undistributable reserves.

As we are an Irish company, Irish dividend withholding tax, or DWT, currently at a rate of 25%, will arise in respect of dividends or other distributions to our shareholders unless an exemption applies. There are exemptions that may be available to U.S. Holders (as defined in “Material U.S. Federal Income Tax Considerations for U.S. Holders”); such shareholders should consult their respective tax advisors. Where DWT arises, we are responsible for deducting DWT at source and accounting for the relevant amount to the Revenue Commissioners of Ireland. See “Tax Considerations—Material Irish Tax Consequences—Withholding Tax on Dividends” and “Description of Share Capital and Constitution—Dividends.”

GH Research PLC was incorporated on March 29, 2021 with an authorized share capital of €25,000, which is the minimum required share capital for an Irish public limited company, divided into 25,000 A ordinary shares, nominal value €1.00 each, or A ordinary shares. The sole subscriber to the incorporation constitution of GH Research PLC was Florian Schönharting who subscribed for 25,000 A ordinary shares of €1.00 each.

On May 27, 2021, GH Research PLC altered its share capital such that its authorized share capital was increased to €25,000 and $1,000,000,000 divided into:

Pursuant to the terms of a share for share exchange agreement as part of our corporate reorganization, referred to herein as our Share Exchange, all shareholders of GH Research Ireland Limited exchanged each of the shares held by them in GH Research Ireland Limited for shares of GH Research PLC of the same share classes with the same shareholders rights as the shares held by them in GH Research Ireland Limited, and as a result, GH Research Ireland Limited became a wholly owned subsidiary of GH Research PLC.

We refer to the reorganization, pursuant to which GH Research PLC acquired all of the interests in GH Research Ireland Limited in exchange for the issuance of the same classes of newly issued shares of GH Research PLC to the shareholders of GH Research Ireland Limited, as our “Corporate Reorganization.”

Upon the completion of the offering, GH Research PLC will redeem 25,000 A ordinary shares of €1.00 each from Florian Schönharting from the proceeds of the new issue for the nominal value of the shares of €25,000 and, following the redemption, in accordance with the Constitution, cancel the 25,000 A ordinary shares.

Pursuant to a shareholder resolution of GH Research PLC, we expect to effect the conversion of (i) 5,923,079 Series A preferred shares of $0.01 each into     ordinary shares of $0.01 each and (ii) 25,379,047 Series B preferred shares of $0.01 each into     ordinary shares subject to the completion of the offering such that the authorized share capital of the Company shall be divided into     ordinary shares of $0.01 each immediately following the completion of the offering.

The investors in this offering will only acquire, and this prospectus only describes the offering of, the ordinary shares of GH Research PLC.

The following table sets forth our total cash and capitalization as of March 31, 2021:

You should read this table in conjunction with our financial statements and related notes included in this prospectus as well as “Use of Proceeds,” “Selected Financial Data” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations.”

The number of ordinary shares outstanding in the table above does not include:

If you invest in our ordinary shares in this offering, your interest will be immediately diluted to the extent of the difference between the initial public offering price per share in this offering and the pro forma as adjusted net tangible book value per share after this offering. Dilution results from the fact that the initial public offering price per share is substantially in excess of the net tangible book value per share.

Our historical net tangible book value as of March 31, 2021 was $4.3 million, or $0.057 per share. Net tangible book value per share is determined by dividing our tangible net worth (defined as total assets, less intangible assets, less total liabilities) by the number of our ordinary and preferred shares outstanding.

As of March 31, 2021, our pro forma net tangible book value would have been $    million, or $    per share. Pro forma net tangible book value represents the amount of our total tangible assets, less our total liabilities, after giving effect to (i) consummation of the Series B Financing and our receipt of net proceeds therefrom, (ii) our Corporate Reorganization and (iii) the conversion of all of our outstanding preferred shares into an aggregate of     ordinary shares upon the completion of this offering. Pro forma net tangible book value per share represents pro forma net tangible book value divided by the total number of shares outstanding as of March 31, 2021, after giving effect to the pro forma adjustments described above.

After giving effect to (i) the Series B Financing; (ii) the Corporate Reorganization; (iii) the conversion of all of our outstanding preferred shares into an aggregate of      ordinary shares upon the completion of this offering; and (iv) the sale of     ordinary shares in this offering at an assumed initial public offering price of $    per share, which is the midpoint of the price range set forth on the cover page of this prospectus, and after deducting underwriting discounts and commissions and estimated offering expenses payable by us, our pro forma as adjusted net tangible book value at March 31, 2021 would have been $    per share. This represents an immediate increase in pro forma as adjusted net tangible book value of $    per share to existing shareholders and immediate dilution of $    per share to new investors.

The following table illustrates this dilution to new investors purchasing ordinary shares in this offering:

Each $1.00 increase or decrease in the assumed initial public offering price of $    per share, which is the midpoint of the price range set forth on the cover page of this prospectus, would increase or decrease our pro forma as adjusted net tangible book value after this offering by $    per share, and would increase or decrease dilution to new investors by $    per share, assuming that the number of ordinary shares offered by us, as set forth on the cover page of this prospectus, remains the same and after deducting underwriting discounts and commissions and the estimated offering expenses payable by us. Each increase of 1,000,000 in the number of ordinary shares we are offering would increase our pro forma as adjusted net tangible book value after this offering by $    per share, and would increase dilution to new investors by $    per share, assuming the assumed initial public offering price per share remains the same and after deducting underwriting discounts and commissions and the estimated offering expenses payable by us. Each decrease of 1,000,000 in the number of ordinary shares we are offering would decrease our pro forma as adjusted net tangible book value after this offering by $    per share, and would increase dilution to new investors by $    per share, assuming an initial

public offering price per share remains the same and after deducting underwriting discounts and commissions and the estimated offering expenses payable by us. The pro forma as adjusted information is illustrative only, and we will adjust this information based on the actual initial public offering price and other terms of this offering determined at pricing.

If the underwriters exercise their option to purchase additional ordinary shares in full, the pro forma as adjusted net tangible book value per share after the offering would be $    , the increase in net tangible book value per share to existing shareholders would be $    and the immediate dilution in net tangible book value per share to new investors in this offering would be $    .

The following table summarizes, on the pro forma as adjusted basis described above as of March 31, 2021, the differences between the existing shareholders and the new investors in this offering with respect to the number of ordinary shares purchased from us, the total consideration paid to us and the average price per share, based on an assumed initial public offering price of $     per share, which is the midpoint of the price range set forth on the cover page of this prospectus, before deducting underwriting discounts and commissions and estimated offering expenses payable by us.

If the underwriters exercise their option to purchase additional ordinary shares in full, the percentage of ordinary shares held by existing shareholders will decrease to     % of the total number of ordinary shares outstanding after the offering, and the number of shares held by new investors will be increased to    , or      % of the total number of ordinary shares outstanding after this offering.

The above discussion and tables are based on     ordinary shares issued and outstanding as of March 31, 2021 after giving effect to the conversion of all of our outstanding preferred shares into     ordinary shares prior to the closing of this offering.

The above discussion and tables excludes    ordinary shares that will be made available for future issuance under our 2021 Equity Incentive Plan, which will become effective in connection with this offering. To the extent that options are issued under our 2021 Equity Incentive Plan, or we issue additional ordinary shares in the future, there will be further dilution to investors participating in this offering.

The selected historical financial data for the years ended December 31, 2020 and 2019 and as of December 31, 2020 and 2019 are derived from our audited financial statements included elsewhere in this prospectus. Our historical results are not necessarily indicative of the results that may be expected in the future and the results for the three months ended March 31, 2021 are not necessarily indicative of the results to be expected for the full year ending December 31, 2021 or any other interim period. We derived the summary historical financial data for the three months ended March 31, 2021 and 2020 and as of March 31, 2021 from the unaudited condensed interim financial statements included elsewhere in this prospectus, which have been prepared on the same basis as the audited financial statements. You should read this data together with our financial statements and related notes appearing elsewhere in this prospectus and the information under the sections titled “Capitalization” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations.”

Our audited financial statements are prepared in accordance with IFRS and presented in U.S. dollars.

Our functional currency is the euro. For financial reporting purposes, our financial statements, which are prepared using the functional currency, have been translated into U.S. dollars. Our assets and liabilities are translated at the exchange rates at the balance sheet date, our revenue and expenses are translated at average exchange rates and shareholders’ equity/(deficit) is translated based on historical exchange rates. Translation adjustments are not included in determining net loss for the period but are included in foreign exchange translation adjustment to other comprehensive loss, a component of total equity.

You should read the following discussion and analysis of our financial condition and results of operations together with the section entitled “Selected Financial Data” and our financial statements and related notes appearing elsewhere in this prospectus. Some of the information contained in this discussion and analysis, including information with respect to our plans and strategy for our business and our expectations with respect to liquidity and capital resources, includes forward-looking statements. These forward-looking statements are subject to numerous risks and uncertainties, including, but not limited to, those risks and uncertainties described in “Risk Factors” and “Cautionary Statement Regarding Forward-Looking Statements” in this prospectus. Our actual results could differ materially from the results described in or implied by these forward-looking statements.

On March 29, 2021, GH Research PLC was incorporated under the laws of Ireland to become the ultimate holding company for GH Research Ireland Limited pursuant to our corporate reorganization. See “Corporate Reorganization.” Prior to this offering, GH Research PLC has only engaged in activities incidental to its formation, the corporate reorganization and this offering. Accordingly, a discussion and analysis of the results of operations and financial condition of GH Research PLC for the period of its operations prior to the corporate reorganization would not be meaningful and are not presented. Following the corporate reorganization, the historical financial statements of GH Research Ireland Limited included in this Registration Statement will become part of the historical consolidated financial statements of GH Research PLC.

We are a clinical-stage biopharmaceutical company dedicated to transforming the treatment of psychiatric and neurological disorders. Our initial focus is on developing our novel and proprietary 5-Methoxy-N,N-Dimethyltryptamine, or 5-MeO-DMT, therapies for the treatment of patients with Treatment-Resistant Depression, or TRD. Our portfolio currently includes GH001, our proprietary inhalable 5-MeO-DMT product candidate which is delivered via a vaporization device produced by a third party, and GH002, our proprietary injectable 5-MeO-DMT product candidate. We have completed a Phase 1 healthy volunteer clinical trial, in which administration of GH001 via inhalation was observed to be well tolerated at the investigated single dose levels and in an individualized dosing regimen with intra-subject dose escalation within a single day. GH001 is currently being investigated in the Phase 2 part of an ongoing Phase 1/2 clinical trial in patients with TRD. Based on observed clinical activity, we believe that administration of a single dose of GH001 has the potential to induce ultra-rapid remissions as measured by the Montgomery-Åsberg Depression Rating Scale, or MADRS, in certain patients, driven by the ultra-rapid onset of psychoactive effects (commonly within seconds) and an intense and short-lived (commonly five to 30 minutes) initial psychoactive experience. The goal of the ongoing Phase 2 part of the trial is to assess whether an individualized dosing regimen with intra-subject dose escalation within a single day can further increase the MADRS remission rate as compared to a single GH001 dose.

We have incurred recurring operating losses since inception, including net losses of $1,149 thousand, $310 thousand and $446 thousand for the three months ended March 31, 2021 and the years ended December 31, 2019 and 2020, respectively. As of March 31, 2021, we had an accumulated deficit of $2 million. We expect to incur significant expenses and operating losses for the foreseeable future as we expand our research and development activities. In addition, our losses from operations may fluctuate significantly from quarter-to-quarter and year-to-year, depending on the timing of our clinical trials and our expenditures on other research and development activities. We anticipate that our expenses will increase significantly in connection with our ongoing activities, as we:

In addition, as we progress toward marketing approval for any of our product candidates, we expect to incur significant commercialization expenses related to product manufacturing, marketing, sales, and distribution.

As a result, we will need substantial additional funding to support our continuing operations and pursue our growth strategy. Until such time as we can generate significant revenue from product sales, if ever, we expect to finance our operations through the sale of equity, debt financings or other capital sources, including potential collaborations with other companies or other strategic transactions. We cannot be certain that additional funding will be available on acceptable terms, or at all. If we fail to raise capital or enter into such agreements as, and when, needed, we may have to significantly delay, scale back, or discontinue the development and commercialization of one or more of our product candidates or other research and development initiatives, which could have a material adverse effect on our business, results of operations, and financial condition. We will need to generate significant revenue to achieve profitability, and we may never do so.

We are subject to a number of risks comparable to those of other similar companies, including dependence on key individuals; the need to develop product candidates with the required safety and efficacy profile and which support regulatory approval and are commercially viable; competition from other companies, many of which are larger and better capitalized; and the need to obtain adequate additional financing to fund the development of our product candidates.

As of March 31, 2021, we had cash of $4.6 million. We believe that our existing cash, together with the net proceeds of $118.8 million from the Series B Financing that closed in April 2021 and the expected net proceeds from this offering, will be sufficient for us to fund our operating expenses and capital

expenditure requirements through      . We have based this estimate on assumptions that may prove to be wrong, and we could exhaust our available capital resources sooner than we expect. See “—Liquidity and Capital Resources—Funding Requirements” below.

With the global spread of the ongoing COVID-19 pandemic in 2021, we have followed guidance issued by national and local governments to address and mitigate the impact of the COVID-19 pandemic on our employees and our business, including our nonclinical studies and clinical trials. We are focused on the health and safety of our employees, and have, among other things, implemented a work-from-home policy and eliminated nonessential business travel. While we are experiencing limited financial impacts at this time, the extent of the impact of the COVID-19 pandemic on our business, operations and development timelines and plans remains highly uncertain. The overall disruption of global healthcare systems and the other risks and uncertainties associated with the pandemic as well as any economic slowdown as a result of the COVID-19 pandemic, could materially and adversely affect our business, financial condition and results of operations. We continue to closely monitor the COVID-19 pandemic as we evolve our business continuity plans, clinical development plans and response strategy.

In addition, our planned clinical trials have been and may continue to be affected by the COVID-19 pandemic, including (i) delays or difficulties in enrolling and retaining patients in our planned clinical trials, including patients that may not be able or willing to comply with clinical trial protocols if quarantines impede patient movement or interrupt healthcare services; (ii) delays or difficulties in clinical site initiation, including difficulties in recruiting and retaining clinical site investigators and clinical site staff as well as closures of trial sites; (iii) diversion or prioritization of healthcare resources away from the conduct of clinical trials and towards the COVID-19 pandemic, including the diversion of hospitals serving as our clinical trial sites and hospital staff supporting the conduct of our clinical trials, and because, who, as healthcare providers, may have heightened exposure to COVID-19 and adversely impact our clinical trial operations; (iv) interruption of our future clinical supply chain or key clinical trial activities, such as clinical trial site monitoring, due to limitations on travel imposed or recommended by federal, state/provincial or municipal governments, employers and others; and (v) limitations in outsourced third-party resources that would otherwise be focused on the conduct of our planned clinical trials, including because of sickness of third-party personnel or their families, or the desire of third-party personnel to avoid contact with large groups of people.

We have not generated any revenue since inception and do not expect to generate any revenue from the sale of products for several years, if at all. If our development efforts for our current or future product candidates are successful and result in regulatory approval or collaboration or license agreements with third parties, we may generate revenue in the future from a combination of product sales or payments from collaboration or license agreements that we may enter into with third parties. Because of the numerous risks and uncertainties associated with product development, regulatory approval and market acceptance, we are unable to predict the amount or timing of product revenue.

Research and development expenses primarily represent costs incurred by us for the following:

We expense research and development costs as incurred. We recognize external development costs based on an evaluation of the progress to completion of specific tasks using information provided to us by our vendors and our clinical investigative sites. Payments for these activities are based on the terms of the individual agreements, which may differ from the pattern of costs incurred, and are reflected in our financial statements as other current assets or other current liabilities. To date, substantially all of our research and development costs have been incurred pursuant to the development of GH001. Therefore, we have not historically tracked expenses by product candidate.

Research and development activities are central to our business model. Product candidates in later stages of clinical development generally have higher development costs than those in earlier stages of clinical development, primarily due to the increased size and duration of later-stage clinical trials and related product manufacturing expenses. As a result, we expect that our research and development expenses will continue to increase over the next several years as we: (i) advance the clinical development of GH001 for TRD; (ii) advance GH001 into clinical development in additional psychiatric and neurological disorders beyond TRD; (iii) advance GH002 and any potential future product candidate into clinical development; and (iv) build our third-party or in-house process development, analytical, manufacturing and related capabilities, increase personnel costs and prepare for regulatory filings related to our potential or future product candidates. We also expect to incur additional IP-related expenses as we file further patent applications and prosecute our intellectual property to protect innovations arising from our research and development activities.

The successful development and commercialization of GH001, GH002 and any potential future product candidate is highly uncertain. This is due to the numerous risks and uncertainties associated with development and commercialization, including the following:

A change in the outcome of any of these variables with respect to the development of our product candidates in nonclinical and clinical development could mean a significant change in the costs and timing associated with their development. For example, if we are required by the FDA, or other comparable foreign regulatory authorities, to perform clinical trials in addition to those that we currently expect, or if there are any delays in establishing appropriate manufacturing arrangements for our product candidates or for the medical devices required to deliver our product candidates, or if there are any delays in completing our clinical trials or the development of any of our product candidates or of the medical devices required to deliver our product candidates.

Our research and development expenses may vary substantially from period to period based on the timing of our research and development activities, including due to timing of initiation of clinical trials and enrollment of patients in clinical trials. Research and development expenses are expected to increase as we advance the clinical development of our inhalable 5-MeO-DMT product candidate GH001, and further advance the research and development of our injectable 5-MeO-DMT product candidate GH002 and any future product candidates. The successful development of our product candidates is highly uncertain.

General and administrative expenses consist primarily of:

We anticipate that our general and administrative expenses will increase in the future as we increase our headcount to support the expected growth in our research and development activities and the potential commercialization of our product candidates. We also expect to incur increased expenses associated with being a public company, including increased costs of accounting, audit, legal, regulatory and tax-related services associated with maintaining compliance with exchange listing and SEC requirements, director and officer insurance costs, investor and public relations costs and costs associated with other administrative and professional services.

Foreign currency translation differences consist of foreign exchange impacts arising from foreign currency transactions.

We are subject to corporate taxation in Ireland. Due to the nature of our business, we have generated losses since inception and have therefore not paid Irish corporation tax.

We have unused net operating losses of $389 thousand, $835 thousand and $2 million as of December 31, 2019 and 2020 and March 31, 2021, respectively. In order to utilize these unused tax losses, we would need to be regarded as carrying on a trade for Irish corporate tax purposes. Once regarded as carrying on a trade and subject to other conditions being met, the unused tax losses can be carried forward indefinitely against future trading income. On this basis, we have decided not to recognize any deferred tax assets at December 31, 2020 or 2019. There is no certainty that we will generate sufficient taxable profits within the required timeframe to be able to utilize these tax loss carry-forwards in full.

The following table summarizes our results of operations for the three months ended March 31, 2021 and 2020 (in thousands):

The following table summarizes our research and development expenses for the three months ended March 31, 2021 and 2020 (in thousands):

Research and development expenses increased by $681 thousand from $11 thousand for the three months ended March 31, 2020, to $692 thousand for the three months ended March 31, 2021. The increase was primarily due to increased costs relating to our technical developments and clinical trials and the hiring of personnel in our research and development team to support the requirements of increased clinical activities.

The following table summarizes our general and administrative expenses for the three months ended March 31, 2021 and 2020 (in thousands):

General and administrative expenses increased by $440 thousand from $8 thousand for the three months ended March 31, 2020, to $448 thousand for the three months ended March 31, 2021. The increase was primarily due to costs incurred in preparation for our initial public offering, including increased costs associated with compliance with exchange listing and SEC requirements as a public company, and the hiring of personnel in our general and administrative functions to support our growth initiatives.

Foreign currency translation differences increased by $9 thousand from $nil for the three months ended March 31, 2020, to a loss of $9 thousand for the three months ended March 31, 2021, due to an increase in foreign currency transactions.

The following table summarizes our results of operations for the years ended December 31, 2020 and 2019 (in thousands):

The following table summarizes our research and development expenses for the years ended December 31, 2020 and 2019 (in thousands):

Research and development expenses increased by $42 thousand from $296 thousand for the year ended December 31, 2019, to $338 thousand for the year ended December 31, 2020. The increase was primarily due to increased costs relating to our technical developments and clinical trials.

We expect these costs to increase materially in the near future, consistent with our plan to advance our GH001 and GH002 product candidates through clinical development. Because substantially all of our research and development costs to date have been incurred pursuant to the development of GH001, we have not historically tracked expenses by product candidate.

The following table summarizes our general and administrative expenses for the years ended December 31, 2020 and 2019 (in thousands):

General and administrative expenses increased by $94 thousand from $14 thousand for the year ended December 31, 2019, to $108 thousand for the year ended December 31, 2020. The increase was primarily due to costs incurred in preparation for our initial public offering, including increased costs associated with compliance with exchange listing and SEC requirements as a public company, and to support our growth initiatives.

We have incurred operating losses since inception, and we have not generated any revenue from any product sales or any other sources. We have not yet commercialized any of our product candidates, which are in various phases of technical and clinical development, and we do not expect to generate revenue from sales of any products for several years, if at all. Until such time as we can generate significant revenue from product sales, if ever, we expect to finance our operations through the sale of equity, debt financings or other capital sources, including potential collaborations with other companies or other strategic transactions. We have funded our operations to date primarily with proceeds from the sale of ordinary shares and preferred stock:

We plan to continue to fund our operating and capital funding needs through sales of additional equity or other forms of financing. We may also consider pursuing strategic partnerships for clinical development and commercialization of our product candidates. The sale of additional equity would result in additional dilution to our shareholders.

The following table provides information regarding our cash flows for the three months ended March 31, 2021 and 2020, as well as for the years ended December 31, 2020 and 2019 (in thousands):

Cash flows used in operating activities increased to $1,087 thousand for the three months ended March 31, 2021 from $102 thousand for the three months ended March 31, 2020, an increase of $985 thousand. The increase was primarily due to a $1,130 thousand increase in loss from operations, partially offset by an increase in changes to working capital of $144 thousand.

Cash flows used in operating activities increased to $330 thousand for the year ended December 31, 2020 from $289 thousand for the year ended December 31, 2019, an increase of $41 thousand. The increase was primarily due to a $136 thousand increase in loss from operations, partially offset by an increase in changes to working capital of $95 thousand.

Cash flows used in investing activities increased to $21 thousand for the three months ended March 31, 2021 from $nil for the three months ended March 31, 2020, an increase of $21 thousand. The increase was due to purchase of property, plant and equipment.

During the years ended December 31, 2020 and December 31, 2019, there were no cash flows used in investing activities.

During the three months ended March 31, 2020 and March 31, 2019, there were no cash flows from financing activities.

Cash flows from financing activities increased to $5.5 million for the year ended December 31, 2020 from $797 thousand for the year ended December 31, 2019, an increase of $4.7 million. The increase was due proceeds from the issuance of Series A preferred shares.

We expect our expenses to increase substantially in connection with our ongoing research and development activities, particularly as we advance the technical development work, nonclinical studies and clinical trials of our product candidates and the medical devices required to deliver such product candidates. In addition, if we obtain regulatory approval for any of our product candidates, we expect to incur significant commercialization expenses related to sales, marketing, manufacturing and distribution. Furthermore, upon the completion of this offering, we expect to incur additional costs associated with operating as a public company. We anticipate that our expenses will increase substantially if and as we:

As of March 31, 2021, we had cash of $4.6 million. Based on our current operating plan, we believe that our existing cash, combined with the net proceeds of $118.8 million from the Series B Financing that closed in April 2021 and the expected net proceeds from this offering, will enable us to fund our operating expenses and capital expenditure requirements through      . However, we have based this estimate on assumptions that may prove to be wrong and we could exhaust our capital resources sooner than we expect.

Because of the numerous risks and uncertainties associated with product development, we may incorrectly estimate the timing and amounts of increased capital outlays and operating expenses associated with completing the research and development of our product candidates. Our funding requirements and timing and amount of our operating expenditures will depend on many factors, including, but not limited to:

Until such time, if ever, as we can generate substantial product revenues, we expect to finance our cash needs through a combination of equity offerings, debt financings, convertible debt financings, strategic collaborations and licensing arrangements. To the extent that we raise additional capital through the sale of equity or convertible debt securities, your ownership interest may be diluted, and the terms of these securities may include liquidation or other preferences that adversely affect your rights as a shareholder. Debt financing, if available, may result in fixed payment obligations and may involve agreements that include covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures or declaring dividends.

If we raise funds through collaborations or marketing, distribution, licensing and royalty arrangements with third parties, we may have to relinquish valuable rights to our intellectual property or technologies, future revenue streams, research programs or product candidates or to grant licenses on terms that may not be favorable to us or issue and sell our shares, which may result in dilution to our shareholders. If we are unable to raise additional funds through equity or debt financings when needed, we may be required to delay, limit, reduce or terminate our product development or future commercialization efforts or grant rights to develop and market product candidates that we would otherwise prefer to develop and market ourselves.

For more information as to the risks associated with our future funding needs, see “Risk Factors.”

As of December 31, 2019 and 2020, we had no material unavoidable contractual obligations or commitments.

During the periods presented, we did not have any off-balance sheet arrangements, as defined in the rules and regulations of the SEC.

During the period from incorporation to March 31, 2021, we have incurred tax losses, which are a potential benefit in the event that we report a taxable profit in the future. In preparing our financial statements, we have assessed that the likelihood of a taxable profit is currently not sufficiently certain for these potential benefits to be recognized as a deferred tax asset. This assessment is based on the status of the research into our principal investigational product and the significant challenges that remain before operating profits can be assured.

In connection with the preparation of our financial statements for the years ended December 31, 2019 and 2020, we identified material weaknesses in our internal control over financial reporting. Specifically, we determined that we lack a sufficient number of trained professionals with an appropriate level of accounting knowledge, training and experience to: (a) design and maintain formal accounting policies, procedures and controls over the fair presentation of our financial statements; and (b) design and maintain controls over the preparation and review of account reconciliations, journal entries and financial statements, including maintaining appropriate segregation of duties.

These control deficiencies did not result in a material misstatement to the financial statements. However, each of these control deficiencies could result in a misstatement of our accounts or disclosures that would result in a material misstatement of our annual or interim financial statements that would not be prevented or detected, and accordingly, we determined that these control deficiencies constitute material weaknesses.

Prior to the completion of this offering, we have been a private company with limited accounting personnel to adequately execute our accounting processes and other supervisory resources with which to address our internal control over financial reporting. We are progressing with the activities necessary to implement the appropriate accounting policies, processes and controls required to comply with Section 404 of the Sarbanes-Oxley Act and are in the process of identifying the relevant individuals with the requisite expertise to assist in implementation activities designed to improve our internal control over financial reporting and remediate the control deficiencies that led to these material weaknesses, including hiring additional finance and accounting personnel and initiating design and implementation of our financial control environment. We cannot assure you that the measures we have taken to date, and actions we may take in the future, will be sufficient to remediate the control deficiencies that led to these material weaknesses in our internal control over financial reporting nor that they will prevent or avoid potential future material weaknesses. We cannot assure you that all of our existing material weaknesses have been identified, or that we will not in the future identify additional material weaknesses. See “Risk Factors— Risks Related to the Offering and Ownership of Our Ordinary Shares—We have identified material weaknesses in our internal control over financial reporting in connection with the audit of our financial statements for the years ended December 31, 2019 and 2020, and we may identify additional material weaknesses. If our remediation of these material weaknesses is not effective, or if we experience additional material weaknesses or otherwise fail to maintain an effective system of internal controls in the future, our ability to accurately or timely report our financial condition or results of operations may be adversely affected.”

On April 5, 2012, the JOBS Act was enacted. As an emerging growth company, or EGC, under the JOBS Act, we may delay the adoption of certain accounting standards until such time as those standards apply to private companies. Other exemptions and reduced reporting requirements under the JOBS Act for EGCs include presentation of only two years of audited financial statements in a registration statement for an initial public offering, an exemption from the requirement to provide an auditor’s report on internal controls over financial reporting pursuant to Section 404(b) of the Sarbanes-Oxley Act of 2002. Additionally, the JOBS Act provides that an EGC can take advantage of an extended transition period for complying with new or revised accounting standards. This transition period is only applicable under U.S. GAAP. As a result, we will adopt new or revised accounting standards on the relevant dates on which adoption of such standards is required or permitted by the International Accounting Standards Board. This allows an EGC to delay the adoption of certain accounting standards until those standards would otherwise apply to private companies. We are in the process of evaluating the benefits of relying on other exemptions and reduced reporting requirements under the JOBS Act. Subject to certain conditions, as an emerging growth company, we intend to rely on certain of these exemptions, including without limitation, (i) providing an auditor’s attestation report on our system of internal controls over financial reporting pursuant to Section 404(b) of the Sarbanes-Oxley Act and (ii) complying with any requirement that may be adopted by the Public Company Accounting Oversight Board, regarding mandatory audit firm rotation or a supplement to the auditor’s report providing additional information about the audit and the financial statements, known as the auditor discussion and analysis.

We will remain classified as an EGC until the earlier of (1) the last day of the fiscal year (i) in which we have total annual gross revenue of $1.07 billion; (ii) following the fifth anniversary of the date of the completion of the offering; or (iii) in which we are deemed to be a “large accelerated filer,” which requires the market value of our ordinary shares that is held by non-affiliates to exceed $700 million as of the prior June 30th, and (2) the date on which we have issued more than $1 billion in nonconvertible debt during the previous three-year period.

As disclosed in Note 2 to our financial statements appearing elsewhere in this prospectus, there are no standards issued but not yet adopted which will have an impact on our financial statements.

The statements about market risk below relate to our historical financial information included in this prospectus.

We operate internationally and are exposed to foreign exchange risk arising from various currency exposures, primarily with respect to pounds sterling.

Transaction exposure arises because the amount of local currency paid or received in transactions denominated in foreign currencies may vary due to changes in exchange rates. Foreign exchange risk arises from:

Management believes that foreign exchange risk is minimal, as we currently maintain our cash balance in euro and our expenses are mainly incurred in euro. We currently have no revenue generating activities.

We are not currently exposed to credit risk except on our cash balances. Our cash balance is maintained with well established, highly rated financial institutions. As of March 31, 2021, the cash balance is held at one bank that has S&P’s credit rating of BBB+. We do not invest in equity instruments or derivatives.

Liquidity risk is the risk that we may not be able to generate sufficient cash resources to settle our obligations in full as they fall due or can do so only on terms that are materially disadvantageous. Prudent liquidity risk management implies maintaining sufficient cash to cover working capital requirements.

Cash is monitored by management. Funding and liquidity risks are reviewed regularly by our board of directors and management. We fund our capital requirements through capital raising.

We are a clinical-stage biopharmaceutical company dedicated to transforming the treatment of psychiatric and neurological disorders. Our initial focus is on developing our novel and proprietary 5-Methoxy-N,N-Dimethyltryptamine, or 5-MeO-DMT, therapies for the treatment of patients with Treatment-Resistant Depression, or TRD. Our portfolio currently includes GH001, our proprietary inhalable 5-MeO-DMT product candidate which is delivered via a vaporization device produced by a third party, and GH002, our proprietary injectable 5-MeO-DMT product candidate. We have completed a Phase 1 healthy volunteer clinical trial, in which administration of GH001 via inhalation was observed to be well tolerated at the investigated single dose levels and in an individualized dosing regimen with intra-subject dose escalation within a single day. GH001 is currently being investigated in the Phase 2 part of an ongoing Phase 1/2 clinical trial in patients with TRD. Based on observed clinical activity, we believe that administration of a single dose of GH001 has the potential to induce ultra-rapid remissions as measured by the Montgomery–Åsberg Depression Rating Scale, or MADRS, in certain patients. The goal of the ongoing Phase 2 part of the trial is to assess whether an individualized dosing regimen with intra-subject dose escalation within a single day can further increase the MADRS remission rate as compared to a single GH001 dose.

Patients with MDD who have not adequately responded to therapy clearly have harder-to-treat depression, generally referred to as TRD. There is no consensus definition for TRD, but in the context of clinical trials, failure of at least one pharmacotherapy, one pharmacotherapy and one psychotherapy, or two pharmacotherapies has been used, the latter group having been referred to by regulatory authorities as patients with TRD. The Sequenced Treatment Alternatives to Relieve Depression, or STAR*D study, a collaborative study funded by the U.S. National Institute of Mental Health, demonstrated that approximately 37% of patients with MDD did not achieve a response despite two treatment steps. Based on this result we estimate that there are approximately nine million TRD patients in the United States and Europe who would be candidates for treatment. TRD has a greater economic and societal cost than non-TRD MDD. For instance, direct medical costs are approximately two- to threefold higher for TRD patients compared to non-TRD MDD patients.

Despite the significant unmet medical need in TRD and the substantial patient population, there are only two pharmacotherapies specifically approved for TRD in the United States: esketamine, as well as a combination of olanzapine and fluoxetine, an antipsychotic and antidepressant, respectively, both of which have shown mixed efficacy in clinical trials and are associated with potential side effects. Outside of pharmacotherapies, psychotherapies are also employed in the treatment of TRD, but involve a lengthy time commitment and are subject to large variability in availability, administration and effectiveness. Multiple forms of somatic intervention, such as rTMS, ECT, VNS and DBS, are another common treatment approach for TRD, although these treatments are often deemed invasive and/or onerous, and there are limited data supporting long-term therapeutic benefit. Despite the range of treatments available for TRD, there is a large unmet medical need for new therapies to bring more patients into rapid and durable remissions and to reduce social and economic burden.

5-MeO-DMT is a serotonergic psychedelic, a class of psychoactive drugs that act primarily through an agonist action on serotonin, or 5-HT, receptors and cause an altered state of consciousness. In vivo and in vitro research from academic studies suggest that 5-MeO-DMT is active at both the 5-HT1A and 5-HT2A receptors, which are expressed in neurons in different areas of the central nervous system. 5-MeO-DMT appears to have a higher affinity for the 5-HT1A receptor subtype and a more selective pattern of distribution across various neurotransmitter receptor types compared to other tryptamines, such as psilocin and N,N-Dimethyltryptamine, or DMT, both of which have stronger affinity for the 5-HT2A receptor subtype and a less selective receptor binding profile.

Our goal is to develop novel and proprietary 5-MeO-DMT therapies for patients with TRD that are highly effective, rapidly acting, well tolerated and conveniently administered. We believe that various distinguishing features of our 5-MeO-DMT product candidates, including our lead product candidate GH001, will allow us to achieve those goals.

First, we believe that GH001 has a high propensity to induce intense psychoactive effects, or Peak Experiences, or PEs, which we believe may be correlated with ultra-rapid induction of durable remissions in patients with TRD. Second, we believe that there is no clinically relevant tolerance development to 5-MeO-DMT when the drug is re-administered within hours and, therefore, no diminished psychoactive effects. Together with the ultra-rapid onset and short duration of psychoactive effects, this aspect allows re-administration of GH001 in an individualized dosing regimen where GH001 can be administered several times within one day. We are currently investigating whether this individualized dosing regimen has the ability to increase the rate of occurrence of PEs in patients with TRD compared to administration of a single dose and whether this results in an increased rate of ultra-rapid remissions, while at the same time avoiding unnecessarily high doses. Third, we believe that the ultra-rapid onset and short duration of the psychoactive effects may confer a significant convenience and feasibility advantage compared to other serotonergic psychoactive agents studied for the treatment of mental disorders, in which the initial psychoactive effects have a slower onset and can last for several hours. We further believe that those features and the type of psychoactive effects induced by GH001 allow for GH001 dosing without the need for lengthy and complex patient preparation prior to the treatment, with only limited required support from a healthcare provider during the experience and without the need for frequent psychological integration work after the experience. GH002 and potential additional product candidates will follow a similar treatment paradigm.

We have completed a Phase 1 clinical trial with seven days of follow-up of GH001, our inhalable 5-MeO-DMT product candidate, in 22 healthy volunteers. Administration via inhalation was observed to be well tolerated at the investigated single dose levels and in the individualized dosing regimen.

We are currently conducting a Phase 1/2 clinical trial with seven days of follow-up of GH001 in 16 patients with TRD. In the completed single-dose Phase 1 part of this trial with two dose levels (12 mg, 18 mg), administration of single doses of GH001 via inhalation was again observed to be well tolerated. We also evaluated clinical activity, as characterized by MADRS remission and MADRS clinical response. Two patients in the 12 mg group and one patient in the 18 mg group of Part A achieved a MADRS remission on day seven after dosing, as well as a MADRS clinical response, and one further patient in the 18 mg group achieved a MADRS clinical response on day seven after dosing.

The ongoing open-label, single-arm Phase 2 part of this trial aims to assess whether applying our individualized dosing regimen with intra-patient dose escalation of GH001 can further increase the MADRS remission rate compared to a single GH001 dose in patients with TRD.

We intend to request a pre-Investigational New Drug application, or pre-IND, meeting with the FDA and a Scientific Advice meeting with the European Medicines Agency, or EMA, and pending the outcome of these meetings, we plan to initiate a multi-center, randomized, controlled Phase 2b trial in TRD. Subject to completing clinical development, we plan to seek regulatory approval of GH001 in both the United States and Europe.

GH002 is our next 5-MeO-DMT product candidate formulated for administration via a proprietary injectable approach. We believe GH002 has the potential to be an attractive therapeutic option, e.g., in patients with underlying airway or pulmonary disease or in situations where it is difficult to assure that the GH001 inhalation is performed adequately, such as in acute psychiatric emergency care situations where a patient may be unable to properly use an inhalation device. GH002 is currently in preclinical development and we anticipate developing GH002 in indications within our focus area of psychiatric and neurological disorders.

We are developing our 5-MeO-DMT product candidates, GH001 and GH002, in our focus area of psychiatric and neurological disorders. Our lead program, GH001, is currently in the Phase 2 part of an ongoing Phase 1/2 clinical trial in patients with TRD. In light of our completed Phase 1 clinical trial of GH001 in healthy volunteers, we plan to request clearance from European regulatory authorities to begin two additional Phase 2 clinical trials in patients with psychiatric or neurological disorders.

Our mission is to develop novel proprietary 5-MeO-DMT therapies to induce ultra-rapid and durable remissions in patients with psychiatric and neurological disorders. In order to achieve this mission, key elements of our strategy include:

We are developing our 5-MeO-DMT product candidates for the treatment of a range of psychiatric and neurological disorders, with an initial focus on TRD, where there is a large unmet medical need. Our goal is to develop new therapies that are rapidly acting, highly effective, well tolerated and conveniently administered.

MDD is a serious mental health condition characterized by recurring episodes where feelings of sadness, loss of interest and other heightened negative emotions occur most of the day, nearly every day. MDD is associated with substantial morbidity, diminished quality of life and reduced life expectancy. The World Health Organization, or WHO, estimated that, as of 2015, more than 320 million people suffered from MDD worldwide and concluded that MDD is the single largest contributor to global disability, accounting for 7.5% of all years lived with disability.

Many experts believe the global burden of MDD will further increase significantly in the wake of the coronavirus disease 2019, or COVID-19, pandemic. Depression symptom prevalence among adults in the United States has been reported to be threefold higher during the COVID-19 pandemic than before.

Unfortunately, the efficacy of the existing anti-depressive treatments is limited by a slow onset of response, and a significant proportion of patients do not adequately respond even after multiple lines of therapy. The STAR*D study, a collaborative study funded by the U.S. National Institute of Mental Health, was designed to assess effectiveness of four different treatment steps, which included both pharmacological and psychotherapeutic approaches, in a generalizable population of patients with depression. An American Journal of Psychiatry report on the STAR*D study by John Rush and co-authors summarized the acute and longer-term outcomes for all four successive treatment steps. The study reported both rates of remission, defined as a score of equal or less than 5 on the 16-item, clinician-rated Quick Inventory of Depressive Symptomatology, or QIDS-C16, and rates of response, defined as at least a 50% reduction in QIDS-C16 from treatment step entry. This STAR*D study found that remission rates were approximately 37%, 31%, 14% and 13% for the first, second, third and fourth treatment steps, respectively, and that the average time to remission in those who did remit across all treatment steps extended to about five to seven weeks. Approximately 33% of patients in the STAR*D study did not achieve a remission despite undergoing four treatment steps.

Patients with MDD who have not adequately responded to adequate therapy clearly have harder-to-treat depression, generally referred to as TRD. There is no consensus definition for TRD, but in the context of clinical trials, failure of at least one pharmacotherapy, one pharmacotherapy and one psychotherapy, or two pharmacotherapies have been used, the latter having been referred to by regulatory authorities as patients with TRD. The STAR*D study demonstrated that approximately 37% of patients with MDD did not achieve a response despite two treatment steps. Based on this result and based on an estimated number of approximately 48 million MDD patients in the United States and Europe according to the National Institute of Mental Health and an article published in European Neuropsychopharmacology, of which, according to the National Institute of Mental Health, about 50% receive treatment with pharmacotherapy or pharmacotherapy and psychotherapy, we estimate that there are approximately nine million TRD patients in the United States and Europe who would be candidates for treatment.

Despite this substantial patient population, only two pharmacotherapies have been approved specifically for the treatment of TRD in the United States: esketamine and a combination of olanzapine and fluoxetine, an antipsychotic and antidepressant, respectively.

Global mental illness-associated costs, including direct costs associated with diagnosis, treatment and care and indirect costs associated with lost productivity and income, were estimated at $2.5 trillion for the year 2010, with the cost projected to surge to $6 trillion by 2030, whereby about two-thirds of the total cost comes from indirect costs, according to a report by the World Economic Forum and the Harvard School of Public Health. According to an article published in the Journal of Clinical Psychiatry, for the United States, the economic burden of MDD alone is estimated to be over $200 billion per year as of 2010, and roughly 47% of this amount is attributable to direct costs, and between 2005 and 2010, the total economic burden of MDD increased by approximately 22%.

TRD has a greater economic and societal cost than non-TRD MDD. TRD patients are often unable to perform daily tasks, are less productive at work and have higher rates of unemployment. They are also more likely to receive disability or welfare benefits and are reported to have a higher rate of co-occurring conditions, including diabetes, anemia and hypertension. According to an article published in the Journal of the Oklahoma State Medical Association, the TRD patient population has an approximate sevenfold

increase in suicide rates compared to non-TRD MDD patients. Research conducted in 2018 and published in the Journal of Affective Disorders suggests that the proportion of patients suffering with TRD attempting suicide at least once during their lifetime could be as high as 30%.

According to a report published in the Journal of Affective Disorders, direct medical costs are approximately two- to threefold higher for TRD patients compared to non-TRD MDD patients. TRD patients have higher prescriptions costs, require more doctor visits and experience increased rates of hospitalization. They also have, on average, twice the number of inpatient visits compared with non-TRD MDD patients and their hospital stays are approximately 36% longer on average, according to an article published in the Journal of Clinical Psychiatry.

Because depression has a diverse set of biological, social, psychological, environmental, genetic and stress-related determinants, many of which co-occur, treatment options are wide-ranging and often combined. Current pharmacological and non-pharmacological treatments are efficacious only for a subset of MDD patients, and many patients do not respond or experience relapses. Clinicians lack high-quality evidence of whether certain therapies are suitable for certain patients and often rely on a lengthy trial-and-error approach, course-correcting as patients experience relapses or difficult side effects.