GH Research (GHRS) Risk Analysis

From time to time we may publicly disclose preliminary, top-line, or interim data from our clinical trials, including the data we have disclosed for our current clinical trials. Preliminary and top-line data are based on an 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 preliminary or top-line 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. Preliminary or top-line 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. We may also conduct planned interim analyses as part of our clinical trials before they are complete. Planned interim analyses 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. As a result, interim analyses, as well as preliminary or top-line data, should be viewed with caution until the final data are available. In addition, the data received from an interim analysis could prompt us to alter the trial design, or even to halt the clinical trial altogether. Finally, we may report interim, preliminary or top-line data of only certain endpoints rather than all endpoints. Adverse changes between interim, preliminary or top-line data and final data, or between the initially planned trial design and any subsequently altered elements of the trial design due to our analysis of interim, preliminary or top-line data, could significantly harm our business and prospects. Additional disclosure of interim, preliminary or top-line data, or of changes to the trial design, 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 top-line data that we report differ from late, final or actual results, if we alter the trial design due to our analysis of interim, preliminary or top-line data, 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.

We are a clinical-stage biopharmaceutical company with a 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. The results of clinical trials with smaller sample sizes, shorter follow-up and no concurrent control group, such as our completed Phase 1 clinical trial of GH001 in 22 healthy volunteers (GH001-HV-101), our completed Phase 1/2 clinical trial of GH001 in 16 patients with Treatment-Resistant Depression, or TRD (GH001-TRD-102), both with seven days follow-up, our completed Phase 1 clinical trial of GH001 in 46 healthy volunteers (GH001-HV-103) with thirty days follow-up, our Phase 2a proof-of-concept clinical trials of GH001 for the treatment of patients with bipolar II disorder, or BDII, and a current depressive episode (GH001-BD-202) and for the treatment of patients with postpartum depression, or PPD (GH001-PPD-203), and our Phase 1 clinical trial of GH002 in 64 healthy volunteers (GH002-HV-105) can each be disproportionately influenced by various biases associated with the conduct of small, uncontrolled, 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 or GH002, 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 clinical trials. To date, our completed clinical trials have been conducted only in Europe, and we have not initiated nor 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 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, in September 2023, our IND for GH001 was placed on a clinical hold by the FDA requiring an inhalation toxicology study in a non-rodent species and an additional inhalation toxicology study. We completed the toxicology studies and met with the FDA, and the clinical hold was lifted by the FDA in December 2025. We cannot assure you that our existing and future INDs will not be subject to additional clinical holds, whether partial or full. In addition, we or another party may uncover a previously unknown risk associated with GH001 and/or 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. If we are not able to complete successful clinical trials on the schedule we expect, we will not be able to obtain regulatory approval, and will not be able to commercialize our product candidates, on the timelines we expect. 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 candidates 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 mebufotenin, which is categorized as a Schedule I controlled substance under the CSA, 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 development work to allow regulatory approval. It is uncertain whether this development work will be successful. A similar context and similar risks apply to our GH002 product candidate. To our knowledge, no mebufotenin 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 EU. Approvals by the European Commission may not be indicative of what the FDA may require for approval and vice versa.

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: - the patient eligibility criteria defined in the protocol;- the size of the patient population required for analysis of the trial's primary endpoints;- in the case of clinical trials focused on rare disease, the small size of the patient population and the potential of a patient being undiagnosed or misdiagnosed;- the proximity of patients to trial sites;- the design of the trial;- our ability to recruit clinical trial investigators with the appropriate competencies and experience;- competing clinical trials and clinicians' and patients' perceptions as to the potential advantages and risks of the product candidate being studied in relation to other available therapies, including any new drugs that may be approved for the indications that we are investigating;- reluctance of physicians to encourage patient participation in clinical trials;- our ability to obtain and maintain patient consents; and - the risk that patients enrolled in clinical trials will drop out of the trials before completion. 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 mebufotenin and other serotonergic psychedelics such as 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, or which may lead to a bias in recruitment between the competing trials, potentially affecting the outcome of those trials. 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 EU, within certain timeframes. Failure to do so can result in fines, adverse publicity and civil and criminal sanctions.

Undesirable adverse drug reactions that could potentially be caused by GH001, GH002 or any other product candidate, and that have been observed in previously completed clinical trials, such as hypertension, tachycardia, nausea, vomiting, sensory disturbance, headache, flashbacks, referred to as the re-experiencing of some of the effects induced by mebufotenin intake at some point after the drug's acute effects have worn off, or that may potentially occur in ongoing or future studies, based on toxicities observed in completed nonclinical toxicity studies, such as serotonin syndrome, convulsions or respiratory adverse events, 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, such as our proprietary aerosol delivery device for GH001, 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: - regulatory authorities may withdraw or limit their approval of such product candidates or medical devices;- regulatory authorities may require the addition of labeling statements, such as a "Boxed Warning" or contraindications;- we may be required to change the way such product candidates are distributed or administered, or change the labeling of the product candidates or medical devices;- the FDA may require a REMS to mitigate risks, which could include medication guides, physician communication plans or elements to assure safe use, such as restricted distribution methods, patient registries and other risk minimization tools, and regulatory authorities in other jurisdictions may require comparable risk mitigation plans;- we may be subject to regulatory investigations and government enforcement actions;- the FDA, EMA or a comparable foreign regulatory authority may require us to conduct additional technical development work or clinical trials or costly post-marketing testing and surveillance to establish and monitor the safety and efficacy of the product;- we may be subject to litigation for injury caused to individuals exposed to or taking our product candidates or operating our medical devices; and - our reputation may suffer. 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 currently requires patients to suspend most of such existing medications or treatments 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 currently have two product candidates in clinical 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 any of 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 have in the past and may in the future reprioritize product candidate development plans and activities 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.

In the EU, 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 EU 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 EU, 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 EU 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 could adversely affect our ability to achieve or sustain profitability.

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 drug application, or 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.

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 EU, 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.

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: - our inability to design such product candidates with the pharmacological or pharmacokinetic properties that we desire; or - potential product candidates may, on further study, be shown to have harmful side effects or other characteristics that indicate that they are unlikely to be medicines that will receive marketing approval and achieve market acceptance. 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.

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 adequate and 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: - nonclinical studies or clinical trials may show the product candidates to be ineffective or less effective than expected (e.g., a clinical trial could fail to meet its primary endpoint(s)) or to have unacceptable side effects or toxicities;- failure to reflect similarly efficacious activity in subsequent clinical trials with larger patient populations;- failure to use clinical endpoints that applicable regulatory authorities would consider clinically meaningful;- manufacturing issues or formulation issues with the product candidate or device that cannot be resolved;- failure to receive the necessary regulatory approvals;- manufacturing issues, formulation issues, pricing or reimbursement issues or other factors that make a product candidate or device uneconomical; and - intellectual property and proprietary rights of others and their competing products and technologies that may prevent one of our product candidates from being commercialized. In particular, our nonclinical studies or clinical trials may show that our product candidates have unacceptable side effects or toxicities. In this context, our completed inhalation toxicology studies in rats showed certain respiratory tract histology findings. While these findings did not affect approval of our ongoing clinical trials in Europe, they prompted the FDA to request additional nonclinical studies to be completed before allowing us to initiate clinical studies in the United States. We completed the nonclinical studies and met with the FDA, and the clinical hold was lifted by the FDA in December 2025. To date, we have assessed the 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, it can be inherently difficult to evaluate, and its psychometric validation has not yet been completed. It is uncertain if regulatory agencies will accept use of this metric to guide dosing in the context of the individualized dosing regimen, or IDR, in our pivotal program. 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 initial Phase 1 clinical trial of GH001 in healthy volunteers (GH001-HV-101), our completed Phase 1/2 clinical trial of GH001 in patients with TRD (GH001-TRD-102) and our completed Phase 2a proof-of-concept clinical trials of GH001 in BDII and a current depressive episode (GH001-BD-202) and in PPD (GH001-PPD-203) 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 major depressive disorder, or 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 mebufotenin, a phenomenon also known as functional unblinding. Therefore, placebo-controlled or active-controlled trials with our product candidates, such as our completed Phase 1 clinical trial of GH001 in healthy volunteers (GH001-HV-103), our completed Phase 2b clinical trial of GH001 in TRD (GH001-TRD-201) and our completed Phase 1 clinical trial of GH002 in healthy volunteers (GH002-HV-105) 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. During the development and regulatory approval process for our product candidates, we engage in discussions with the FDA, the EMA and other comparable foreign regulatory authorities regarding our development programs, including discussions about the regulatory requirements for approval. As part of these discussions, different regulatory authorities may provide different or conflicting advice. While we attempt to harmonize the advice we receive from multiple regulatory authorities, it is not always practical to do so. Also, we may choose not to harmonize conflicting advice when harmonization would significantly delay clinical trial data or when we believe it is otherwise inappropriate. In addition, regulatory authorities may change their views on aspects of the clinical program, including study designs, or the ability of the studies as designed to support approval of a product candidate. 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 exclusively been conducted in Europe. 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. For example, our nonclinical data and device design verification information submitted with our GH001 IND was deemed by the FDA to contain insufficient information to assess risks to human subjects, and the FDA therefore requested additional nonclinical toxicology studies and other work (including acceptable device design verification information) before allowing us to initiate clinical studies in the United States. We completed the nonclinical and other studies and met with the FDA, and the clinical hold was lifted by the FDA in December 2025. 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.

The development process for our proprietary GH001 aerosol delivery device is incomplete. As a clinical-stage biopharmaceutical company, we do not have significant experience in manufacturing medical devices, or in working with a contract development and manufacturing organization, or CDMO, to manufacture medical devices, and as such we may not develop a device that is satisfactory either for our purposes or for necessary regulatory approvals. Further, a significant number of components in our proprietary aerosol delivery device for GH001 are manufactured in China, subjecting us to certain geopolitical risks, and other risks related to our supply chain, in manufacturing our device. See "Risks Related to Employee Matters, Managing Our Business and Operations-Our business is subject to economic, political, regulatory and other risks associated with international operations." The regulatory pathway relating to approval of our device is highly complex as a result of the novelty of our device and the absence of established regulatory guidance applicable to our device presentation. The FDA, EMA, or other comparable foreign regulatory authorities, as applicable, may not accept our interpretation of existing guidance, which may impact the timelines for regulatory approval or result in a failure to obtain regulatory approval of our device at all. Even if we ultimately develop a device that is suitable to generate a pharmaceutically acceptable aerosol and which achieves sufficient uptake of mebufotenin into the systemic circulation, and even if such device is approved, or exempt from approval requirements, as the case may be, by the FDA, EMA, or other comparable foreign regulatory authorities, there can be no assurance that we will be able to adequately manufacture such device in sufficient quantities, or at costs acceptable to us, or that third-party payors will adequately reimburse for them, to achieve our pre-commercial and commercial goals. Any such inability to adequately manufacture our device could materially delay our clinical trials or otherwise materially impact our business. Further, our future success may depend in part on our ability to enhance our proprietary aerosol delivery device as well as develop or acquire new technologies to keep pace with technological developments, evolving industry standards and responses to changes in patient needs and expectations. A failure to adequately develop enhancements and improvements to our proprietary aerosol delivery device or acquire new devices that will address changing technologies and patient requirements adequately, or to introduce such devices on a timely basis, may have a material adverse effect on our clinical trials, business, financial condition and results of operations.

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 any 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 and 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 completed clinical trials have been conducted exclusively in Europe. We plan to pursue clinical trials in additional European countries and the United States for all of our clinical programs. We do not expect that we need to submit separate Investigational Device Exemption applications, or IDEs, or other comparable applications, with the FDA for the medical devices, including our proprietary aerosol delivery device, that we use 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. We also intend to seek regulatory approval for some or all of our product candidates outside of the United States, including the EU. We do expect separate applications to EU national member state authorities will be required for our proprietary aerosol delivery device for GH001 and may be required for other medical devices that we use to deliver our product candidates. Application requirements outside of the United States and the EU are less well understood at this time and separate applications may be needed. If the FDA or another comparable foreign regulatory authority were to conclude that any such medical device requires an IDE submission or a comparable application, it could delay or prevent us from utilizing such medical device in future trials. Even if we were to submit an IDE or a comparable application for the medical device, the FDA or other comparable foreign regulatory authorities may not grant necessary approvals requested by us in a timely manner, or at all. 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, such as our proprietary aerosol delivery device for GH001, or our ability to commercialize any products, including: - delay or failure in establishing acceptable performance characteristics, quality manufacturing standards and manufacturing capabilities for our product candidates or for the medical devices required to deliver our product candidates;- negative or inconclusive results from our nonclinical studies or clinical trials or the clinical trials of others for product candidates similar to ours, leading to a decision or requirement to conduct additional nonclinical testing or clinical trials or abandon a program;- product or device-related side effects experienced by subjects in our clinical trials or by individuals using drugs or therapeutics similar to our product candidates;- delays in submitting INDs (or IDEs, if applicable) in the United States or comparable foreign applications or delays or failure in obtaining the necessary approvals from regulators or institutional review boards, or IRBs, to commence a clinical trial, including Schedule I research protocols required by the DEA, or a suspension or termination of a clinical trial once commenced;- if the FDA, EMA or other comparable foreign regulatory authorities do not find the earlier technical, nonclinical and clinical trial work sufficient, then we may need to conduct additional technical development work or nonclinical or clinical trials beyond what we currently have planned, before we can initiate further clinical studies. Any significant technical development, nonclinical or clinical trial delays could also shorten any periods during which we may have the exclusive right to commercialize our drug candidates and medical devices or allow our competitors to bring products to market before we do and impair our ability to successfully commercialize our drug candidates and medical devices and may harm our business and results of operations;- conditions imposed by the FDA, EMA or other comparable foreign regulatory authorities regarding the scope or design of our clinical trials;- the FDA, EMA or other comparable foreign regulatory authorities may disagree with our clinical trial design, including with respect to dosing levels administered in our planned clinical trials, or the medical devices used to deliver our product candidates in the clinical trials, which may delay or prevent us from initiating our clinical trials with our originally intended trial design and the originally planned medical devices;- delays in contracting with clinical trial sites or enrolling subjects in clinical trials, the inability to identify clinical trial sites willing to host our clinical trials and the required scheduled drug DEA researcher registration and Schedule I research protocol in the United States and similar licenses in other jurisdictions to be obtained and maintained by our clinical investigators;- delays or interruptions in the supply of materials necessary for the conduct of our clinical trials;- regulators, IRBs or ethics committees may not authorize us or our investigators to commence a clinical trial or conduct a clinical trial at a prospective trial site;- the FDA, the EMA or other comparable foreign regulatory authorities may require us to submit additional data such as long-term toxicology studies or additional data for our product candidates or the medical devices required to deliver our product candidates;- delays in reaching, or failure to reach, agreement on acceptable terms with prospective trial sites and prospective contract research organizations, or CROs, which can be subject to extensive negotiation and may vary significantly among different CROs and trial sites;- the number of subjects required for clinical trials of any product candidates may be larger than we anticipate, or subjects may drop out of these clinical trials or fail to return for post-treatment follow-up at a higher rate than we anticipate;- our third-party contractors for nonclinical studies or clinical trials may fail to comply with regulatory requirements or meet their contractual obligations to us in a timely manner, or at all, or may deviate from the clinical trial protocol or take actions that could cause clinical trial sites or clinical investigators to drop out of the trial, which may require that we add new clinical trial sites or investigators;- due to the impact of a pandemic, epidemic, outbreak of an infectious disease or a similar event, we may experience some delays and interruptions to our technical development efforts, nonclinical studies, clinical trials and/or regulatory approvals, we may experience delays or interruptions to our manufacturing supply chain, or we could suffer delays in reaching, or we may fail to reach, agreement on acceptable terms with third-party service providers on whom we rely;- greater-than-anticipated clinical trial costs, including as a result of delays or interruptions that could increase the overall costs to finish our clinical trials as our fixed costs are not substantially reduced during delays;- we may elect to, or regulators, IRBs, Data Safety Monitoring Boards, or DSMBs, or ethics committees may require that we or our investigators, suspend or terminate clinical research or trials for various reasons, including non-compliance with regulatory requirements or a finding that the participants are being exposed to unacceptable health risks;- we may not have the financial resources available to begin and complete the planned trials, or the cost of clinical trials of any product candidates may be greater than we anticipate;- the supply or quality of our product candidates, medical devices required to deliver our product candidates, or other materials necessary to conduct clinical trials of our product candidates may be insufficient or inadequate to initiate or complete a given clinical trial;- inability to compete with other therapies;- poor efficacy of our product candidates during clinical trials;- failure to demonstrate an acceptable benefit/risk profile for our product candidates;- inability to provide sufficient design, testing, manufacturing and quality information for the medical devices required to deliver our product candidates, including information to support their use and compatibility with the drug constituent of our product candidates;- unfavorable FDA, EMA or other comparable foreign regulatory authority inspection and review of clinical trial sites or manufacturing facilities;- if the DEA, or any state or other jurisdiction, delays rescheduling or fails to reschedule mebufotenin to Schedule II, III, IV or V, or delays classifying or fails to classify our product candidates to Schedule II, III, IV or V;- unfavorable product labeling associated with any product approvals and any requirements for a Risk Evaluation and Mitigation Strategy, or REMS, that may be required by the FDA or comparable requirements in other jurisdictions to ensure the benefits of an individual product outweigh its risks;- unfavorable acceptance of our product candidates or clinical trial data by the patient or medical communities or third-party payors;- failure of our third-party contractors or investigators to comply with regulatory requirements or otherwise meet their contractual obligations in a timely manner, or at all;- delays and changes in regulatory requirements, policy and guidelines, including the imposition of additional regulatory oversight around clinical testing generally or with respect to our technology in particular;- varying interpretations of data by the FDA, EMA or other comparable foreign regulatory authorities; or - we may experience cyber-attacks or other failures in our telecommunications or IT systems, or those of our collaborators, CROs, third-party logistics or other service providers, distributors, suppliers or other contractors or consultants. We do not have complete control over many of these factors, including certain aspects of technical drug product and device development, nonclinical 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 mebufotenin 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 mebufotenin into the systemic circulation, such as its particle size distribution. The generation of this mebufotenin 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. For GH002, which is our intravenous mebufotenin formulation, such classification will depend on our final choice for its commercial presentation. Products that are considered to be drug-device combination products will require review and coordination by the drug and device centers within the FDA, or other comparable foreign regulatory authorities or notified bodies 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 Management System, or QMS, and regulations applicable to medical devices. Combination products are also subject to the Medical Device Regulation 2017/745, or MDR, which requires 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. For example, 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 Storz & Bickel, Tuttlingen. 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. We also have not established licensing agreements with any alternative provider of a device which would be suitable to generate a pharmaceutically acceptable aerosol from GH001. In 2021, we initiated the development of a proprietary aerosol delivery device for GH001 for use in our pivotal clinical trial program and for commercial use. This development is not yet completed and if we fail to develop, manufacture, license, or acquire a device which would be suitable to generate a pharmaceutically acceptable aerosol from GH001, which achieves sufficient uptake of mebufotenin into the systemic circulation, or if we fail to get sufficient supplies of the third-party manufactured 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 license an alternative device component, we will need to perform validation testing and obtain FDA, or other comparable foreign regulatory authority or notified body, approval prior to using the modified or alternative device or device component. Similar testing and validation would be required for our development of any proprietary devices. If the FDA or other comparable foreign regulatory or notified 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, such as our proprietary aerosol delivery device for GH001, 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.

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: - completing research and technical, nonclinical and clinical development of our product candidates and the medical devices required to deliver these product candidates, such as our proprietary aerosol delivery device for GH001;- obtaining regulatory approvals and marketing authorizations for product candidates, including the medical devices required to deliver these product candidates for which we successfully complete clinical development and clinical trials;- developing a sustainable and scalable manufacturing process for our product candidates and the medical devices required to deliver these product candidates, as well as establishing and maintaining commercially viable supply relationships with third parties that can provide adequate products and services to support clinical activities and commercial demand of our product candidates and medical devices;- identifying, assessing, acquiring and/or developing new product candidates;- negotiating favorable terms in any collaboration, licensing or other arrangements into which we may enter;- successfully getting our product candidates rescheduled under the federal Comprehensive Drug Abuse Prevention and Control Act of 1970, also known as the Controlled Substances Act, or CSA, and comparable state laws by the DEA and other applicable regulatory agencies inside and outside the United States;- launching and successfully commercializing product candidates and the medical devices required to deliver these product candidates for which we obtain regulatory approval, either by collaborating with a partner or, if launched independently, by establishing a sales, marketing and distribution infrastructure;- obtaining and maintaining an adequate price for our product candidates and devices in the countries where our products are commercialized;- obtaining coverage and adequate reimbursement for our product candidates and medical devices from payors;- obtaining market acceptance of our product candidates as viable treatment options;- addressing any competing technological and market developments;- receiving milestone and other payments under any future collaboration arrangements;- maintaining, protecting, expanding and enforcing our portfolio of intellectual property rights, including patents, trade secrets and know-how;- attracting, hiring and retaining qualified personnel; and - complying with laws and regulations, including laws applicable to controlled substances, data privacy and pre-commercial activities. 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.