UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 10-K

⊠ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended December 31, 2023

OR

☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from ________ to ________

Commission File Number: 001-39522

COMPASS Pathways plc

(Exact name of registrant as specified in its charter)

England and Wales	Not Applicable
(State or other jurisdiction of incorporation or organization)	(I.R.S. Employer Identification No.)

33 Broadwick Street

London W1F 0DQ

United Kingdom

(Address of principal executive offices, zip code)

+1 (716) 676-6461

(Registrant’s telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:

Title of Each Class	Trading Symbol	Name of each exchange on which registered
American Depositary Shares, each representing one ordinary share, par value of £0.008 per share	CMPS	Nasdaq Global Select Market

Securities registered pursuant to Section 12(g) of the Act: None.

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes ☐ No ☒

Indicate by check mark if the Registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes ☐ No ☒

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☒ No ☐

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes ☒ No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer	☐	Accelerated filer	☐
Non-accelerated filer	☒	Smaller reporting company	☒
		Emerging growth company	☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ☐

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements

of the registrant included in the filing reflect the correction of an error to previously issued financial statements. ☐

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant

to §240.10D-1(b). ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ☐ No ☒

The aggregate market value of ordinary shares held by non-affiliates of the Registrant as of June 30, 2023, the last business day of the most recently completed second fiscal quarter, was $215.7 million. This calculation does not reflect a determination that certain persons are affiliates of the Registrant for any other purpose.

The registrant had 64,227,371 shares of common stock outstanding as of February 23, 2024.

DOCUMENTS INCORPORATED BY REFERENCE

Portions of the Registrant’s Proxy Statement for the 2024 Annual Meeting of Shareholders are incorporated herein by reference into Part III of this Annual Report on Form 10-K to the extent stated herein. Such proxy statement will be filed with the Securities and Exchange Commission within 120 days of the Registrant’s fiscal year ending December 31, 2023.

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PART I
Item 1.	Business	7
Item 1A.	Risk Factors	55
Item 1B.	Unresolved Staff Comments	149
Item 1C.	Cybersecurity	149
Item 2.	Properties	150
Item 3.	Legal Proceedings	150
Item 4.	Mine Safety Disclosures	150
PART II
Item 5.	Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities	151
Item 6.	[Reserved]	151
Item 7.	Management’s Discussion and Analysis of Financial Condition and Results of Operations	152
Item 7A.	Quantitative and Qualitative Disclosures About Market Risk	166
Item 8.	Financial Statements and Supplementary Data	167
Item 9.	Changes in and Disagreements with Accountants on Accounting and Financial Disclosure	167
Item 9A.	Controls and Procedures	167
Item 9B.	Other Information	168
Item 9C.	Disclosure Regarding Foreign Jurisdictions that Prevent Inspections	176
PART III
Item 10.	Directors, Executive Officers and Corporate Governance	177
Item 11.	Executive Compensation	177
Item 12.	Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters	177
Item 13.	Certain Relationships and Related Transactions, and Director Independence	177
Item 14.	Principal Accountant Fees and Services	177
PART IV
Item 15.	Exhibit and Financial Statement Schedules	178
Item 16.	Form 10-K Summary	181
	Signatures	F-27

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SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This Annual Report on Form 10-K includes forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, or the “Securities Act,” and Section 21E of the Securities Exchange Act of 1934, as amended, or the “Exchange Act”. Forward-looking statements generally relate to future events or our future financial or operating performance. All statements other than statements of historical fact included in this Annual Report on Form 10-K, including regarding our strategy, future operations, financial position, estimated revenues and losses, projected costs, prospects, plans and objectives of management, are forward-looking statements. In some cases, you can identify forward-looking statements because they contain words such as “may,” “will,” “should,” “expects,” “plans,” “anticipates,” “could,” “intends,” “target,” “projects,” “contemplates,” “believes,” “estimates,” “predicts,” “potential” or “continue” or the negative of these words or other similar terms or expressions. The forward-looking statements and opinions contained in this Form 10-K are based upon information available to our management as of the date of this Form 10-K, 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. Forward-looking statements contained in this Annual Report on Form 10-K include, but are not limited to, statements about:

•the timing, progress and results of our Phase 3 clinical program for treatment-resistant depression, or TRD and our other clinical trials of investigational COMP360 psilocybin treatment, including statements regarding the timing of initiation and completion of trials or studies and related preparatory work, our expectations regarding results of discussions with the Food and Drug Administration, or FDA, regarding our trial design and protocols, and our expectations regarding the periods during which the results of our clinical trials will become available;

•our estimates regarding our expenses, capital requirements, the sufficiency of our cash resources, our expected cash runway and needs for and ability to raise additional financing;

•the potential for all of the warrants issued in our private placement financing in August 2023, or the PIPE Warrants, to be exercised in full for cash, and any expected proceeds from the exercise of the PIPE Warrants, including the risk that the pending exercises of certain PIPE Warrants for approximately $8.9 million in proceeds will not settle;

•our reliance on the success of our investigational COMP360 psilocybin treatment;

•the timing, scope or likelihood of regulatory filings and approvals;

•our expectations regarding the size of the eligible patient populations for COMP360 psilocybin treatment, if approved for commercial use;

•our ability to identify third-party clinical sites to conduct our trials and our ability to identify and train appropriately qualified therapists to administer COMP360 psilocybin treatment in our clinical trials;

•our ability to implement our business model and our strategic plans for our business and our investigational COMP360 psilocybin treatment;

•our ability to identify new indications for COMP360 beyond our current primary focus on TRD, post-traumatic stress disorder, or PTSD and anorexia nervosa;

•our ability to identify, develop or acquire digital technologies to enhance our administration of our investigational COMP360 psilocybin treatment;

•our ability to leverage our technology and drug development candidates to advance new psychedelic compounds in other areas of unmet mental health need;

•our ability to successfully establish and maintain Centers of Excellence and our ability to achieve our goals with respect to the Center for Mental Health Research and Innovation;

•our commercialization, marketing and manufacturing capabilities and strategy;

•the pricing, coverage and reimbursement of our investigational COMP360 psilocybin treatment, if approved;

•the scalability and commercial viability of our manufacturing methods and processes;

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•the rate and degree of market acceptance and clinical utility of our investigational COMP360 psilocybin treatment, in particular, and psilocybin-based treatments, in general;

•our ability to establish or maintain collaborations or strategic relationships or obtain additional funding;

•our expectations regarding potential benefits of our investigational COMP360 psilocybin treatment and our treatment approach generally;

•our expectations around feedback from and discussions with regulators, regulatory development paths and with respect to Controlled Substances Act designation;

•the scope of protection we and any current or future licensors or collaboration partners are able to establish and maintain for intellectual property rights covering COMP360;

•our ability to operate our business without infringing, misappropriating, or otherwise violating the intellectual property rights and proprietary technology of third parties;

•regulatory developments in the United States, under the laws and regulations of England and Wales, and other jurisdictions;

•developments and projections relating to our competitors and our industry;

•the effectiveness of our internal control over financial reporting;

•our ability to attract and retain qualified employees and key personnel;

•our ability to meet milestones to draw down additional amounts in accordance with the terms of our Loan and Security Agreement, or the Loan Agreement, with Hercules Capital, Inc., or Hercules, and our ability to comply with the operating and financial covenants in our Loan Agreement;

•the effect of global financial and economic conditions and geopolitical events, including instability in the banking system, fluctuating interest rates and inflation, and foreign exchange fluctuations, particularly the Pound Sterling to U.S. Dollar, the risk of economic slowdown or recession in the United States, overall market volatility in the United States or the United Kingdom, including as a result of, among other factors, the ongoing war between Russia and Ukraine, the Israel-Hamas war, a potential government shutdown in the United States, the upcoming presidential election in the United States. or similar events, on our business;

•the effect of public health crises, pandemics or epidemics such as the COVID-19 pandemic, and any future mitigation efforts, and current or future economic effects, on any of the foregoing or other aspects of our business or operations;

•whether we are classified as a controlled foreign corporation, or CFC, or a passive foreign investment company, or PFIC, under the Internal Revenue Code of 1986, as amended, for current and future periods; and

•the future trading price of the American Depositary Shares, or the ADSs, and impact of securities analysts’ reports on these prices.

We caution you that the foregoing list may not contain all of the forward-looking statements made in this Form 10-K.

You should not rely upon forward-looking statements as predictions of future events, which speak only as of the date made. We have based the forward-looking statements contained in this Annual Report on Form 10-K primarily on our current expectations and projections about future events and trends that we believe may affect our business, financial condition, results of operations and prospects. The outcomes of the events described in these forward-looking statements are subject to risks, uncertainties and other factors described in the section titled “Risk Factors” in Part I, Item 1A, of this Annual Report on Form 10-K and our other filings with the Securities and Exchange Commission, or the SEC. Moreover, we operate in a very competitive and rapidly changing environment. New risks and uncertainties emerge from time to time and it is not possible for us to predict all risks and uncertainties that could have an impact on the forward-looking statements contained in this Annual Report on Form 10-K. We cannot assure you that the results, events and circumstances reflected in the forward-looking statements will be achieved or occur, and actual results, events or circumstances could differ materially from those described in the forward-looking statements. Except as otherwise required by the securities laws of the United States, we disclaim any obligation to subsequently revise any forward-looking statements to reflect events or circumstances after the date of such statements or to reflect the occurrence of anticipated or unanticipated events. 

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SUMMARY OF THE MATERIAL RISKS ASSOCIATED WITH OUR BUSINESS

Our business is subject to numerous risks and uncertainties that you should be aware of in evaluating our business. These risks and uncertainties include, but are not limited to, the following:

•We are a clinical-stage biotechnology company and have incurred significant losses since our inception. We expect to incur losses for the foreseeable future and may never achieve or maintain profitability;

•We will need substantial additional funding to complete the development and commercialization of our investigational COMP360 psilocybin treatment. Our ability to raise additional funds may be adversely impacted by macroeconomic conditions and disruptions to and volatility in the credit and financial markets in the United States and worldwide, including instability in the banking system, fluctuating interest rates and inflation and the risk of credit-rating downgrades and economic slowdown or recession in the United States. Failure to obtain additional funding when needed or on favorable terms may force us to delay, limit or terminate certain or all of our product discovery, therapeutic development, research operations or commercialization efforts or grant rights to develop and market products or therapeutic candidates that we would otherwise prefer to develop and market ourselves;

•Raising additional capital through the sale of equity securities, including through the exercise of the PIPE Warrants, may cause significant dilution to holders of our ordinary shares and ADSs, and raising additional capital through debt financings or strategic partnerships or collaborations may restrict our operations or require us to relinquish rights to COMP360 or any future therapeutic candidates;

•We are dependent on the successful development of our investigational COMP360 psilocybin treatment. We cannot give any assurance that COMP360 will successfully complete clinical trials or receive regulatory approval, which is necessary before it can be commercialized;

•COMP360 is, and any future therapeutic candidates we may develop may be, subject to controlled substance laws and regulations in the jurisdictions where our products, if approved, may be marketed, and failure to comply with these laws and regulations, or the cost of compliance with these laws and regulations, or changes in these laws and regulations may adversely affect the results of our business operations, both during clinical development and post approval, and our financial condition. In addition, during the review process of COMP360, and prior to any potential approval, the FDA and/or other regulatory bodies may require additional data, including with respect to whether COMP360 has abuse or misuse potential, which may delay approval and any potential rescheduling process;

•COMP360 contains controlled substances, the use of which may generate public controversy. Adverse publicity or public perception regarding COMP360, in particular, and psilocybin-based treatments, in general, or our current or future investigational treatments using psilocybin may negatively influence the success of these treatments;

•Clinical drug development is a lengthy and expensive process with uncertain timelines and uncertain outcomes. If clinical trials of COMP360 psilocybin treatment or any future therapeutic candidates are prolonged or delayed, we or our current or future collaborators may be unable to obtain required regulatory approvals, and therefore we will be unable to commercialize our investigational COMP360 psilocybin treatment or any future therapeutic candidates on a timely basis or at all, which will adversely affect our business;

•COMP360 psilocybin treatment and any future therapeutic candidates we may develop may have serious adverse, undesirable or unacceptable side effects which may delay or prevent marketing approval. If such side effects are identified during the development of COMP360 psilocybin treatment or any future therapeutic candidates or following approval, if any, we may need to abandon our development of such therapeutic candidates, the commercial profile of any approved label may be limited, or we may be subject to other significant negative consequences;

•Research and development of drugs targeting the central nervous system is particularly difficult, which makes it difficult to predict and understand why the drug has a positive effect on some patients but not others;

•We have never commercialized a therapeutic candidate before and may lack the necessary expertise, personnel and resources to successfully commercialize our treatments on our own or with suitable collaborators;

•The future commercial success of our investigational COMP360 psilocybin treatment or any future therapeutic candidates will depend on the degree of market access and acceptance of our potential treatments among healthcare professionals, patients, healthcare payors, health technology assessment bodies and the medical community at large;

•Our business and commercialization strategy for our investigational COMP360 psilocybin treatment depends on our ability to identify, qualify, prepare, and support third-party treatment centers. If we are unable to do so, our

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commercialization prospects would be limited and our business, financial condition and results of operations would be harmed;

•We currently rely on specially trained therapists working at third-party clinical trial sites to administer our investigational COMP360 psilocybin treatment in our clinical trials and we expect this to continue upon approval, if any, of COMP360 or any future psychedelic-based drug candidates. If third-party sites fail to recruit and retain a sufficient number of therapists or effectively manage their therapists, our business, financial condition and results of operations would be materially harmed;

•Intellectual property rights of third parties could adversely affect our ability to develop or commercialize our investigational treatments, such that we could be required to litigate or obtain licenses from third parties in order to develop or market our investigational treatments. Such litigation or licenses could be costly or not available on commercially reasonable terms;

•Others may claim an ownership interest in our intellectual property and our product candidates, which could expose us to litigation and have a significant adverse effect on our prospects;

•Our failure to comply with the financial and other covenants or payment obligations under our existing Loan Agreement with Hercules could result in a default or an event of default, which may result in increased interest charges, acceleration of our repayment obligations or other actions by Hercules, any of which could negatively impact our business, financial condition and results of operations;

•Enacted and future legislation may increase the difficulty and cost for us to obtain marketing approval of and commercialize our investigational COMP360 psilocybin treatment or any future therapeutic candidates and could have a material adverse effect on our business;

•We rely on third parties to supply and manufacture the psilocybin and psilocin incorporated in COMP360 and expect to continue to rely on third parties to supply and manufacture any future therapeutic candidates, and we will rely on third parties to manufacture these substances for commercial supply, if approved. If any third-party provider fails to meet its obligations to manufacture COMP360 or our future therapeutic candidates, or fails to maintain or achieve satisfactory regulatory compliance, the development of such substances and the commercialization of any treatments, if approved, could be stopped, delayed or made commercially unviable, less profitable or may result in enforcement actions against us;

•There are a number of third parties who conduct investigator-initiated studies, or IISs, using COMP360 provided by us. Any failure by a third party to meet its obligations with respect to the clinical development of our investigational COMP360 psilocybin treatment or any future therapeutic candidates may delay or impair our ability to obtain regulatory approval for COMP360. IISs of COMP360 or any future therapeutic candidates may generate clinical trial data that raises concerns regarding the safety or effectiveness of COMP360 and any data generated in IISs may not be predictive of the results in populations or indications in which we are conducting, or plan to conduct, clinical trials;

•Unfavorable global economic conditions could adversely affect our business, financial condition or results of operations. Economic uncertainty and worsening or deteriorating global economic conditions and volatile financial market conditions in the United States or the United Kingdom, as a result of, among other factors, instability in the banking system, fluctuating inflation and interest rates, the risk of economic slowdown or recession or a government shutdown in the United States, the upcoming presidential elections in the United States and the ongoing war between Russia and Ukraine, the Israel-Hamas war or similar events, may materially and adversely affect our business, including our ability to raise capital and our financial results;

•A pandemic, epidemic, or outbreak of an infectious disease, or new variants of COVID-19, may materially and adversely affect our business, including our preclinical studies, clinical trials, third parties on whom we rely, our supply chain, our ability to raise capital, our ability to conduct regular business and our financial results;

•We face substantial competition and our competitors may discover, develop or commercialize treatments before or more successfully than us, which may result in the reduction or elimination of our commercial opportunities;

•Our business is subject to economic, political, regulatory and other risks associated with international operations; and

•We may face business interruptions, data loss, unauthorized access to or disclosure of personal health information or other personally identifiable information, failures or significant downtime of our information technology systems, negative publicity or reputational damage resulting from cyber-attacks on our systems or other cybersecurity incidents.

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PART I

ITEM 1. BUSINESS

Overview

We are a biotechnology company dedicated to accelerating patient access to evidence-based innovation in mental health. We are motivated by the need to find better ways to help and empower people suffering with mental health challenges who are not helped by existing treatments, and are pioneering the development of a new model of psilocybin treatment, in which our investigational COMP360 psilocybin is administered in conjunction with psychological support, which we refer to as COMP360 psilocybin treatment. COMP360 is our proprietary psilocybin formulation that includes our pharmaceutical-grade polymorphic crystalline psilocybin, optimized for stability and purity.

We believe that our COMP360 psilocybin treatment - combining COMP360 psilocybin with psychological support from specially trained therapists - could offer a new approach to treatment of serious mental health conditions, including treatment-resistant depression, or TRD, a subset of major depressive disorder, or MDD, post-traumatic stress disorder, or PTSD, and anorexia nervosa.

Our initial focus is on TRD, comprising patients who are inadequately served by the current treatment paradigm. In 2018, we received Breakthrough Therapy designation from the FDA for COMP360 for the treatment of TRD. In November 2021, we announced positive top-line results from our Phase 2b clinical trial evaluating COMP360 in conjunction with psychological support for the treatment of TRD. On November 3, 2022, The New England Journal of Medicine, the world’s leading peer-reviewed medical journal, published the positive results from our Phase 2b trial. This is the largest, randomized, controlled, double-blind psilocybin treatment clinical trial completed to date. The objective of the Phase 2b study was to evaluate the efficacy and safety of a single dose of investigational COMP360 psilocybin (25mg or 10mg), compared to 1mg, in patients with TRD. The results from the 233-participant trial showed a rapid and sustained response for patients receiving a single 25mg dose of COMP360 psilocybin administered with psychological support, with 29.1% of participants in remission by week 3 (p<0.002). The trial achieved its primary endpoint for the 25mg dose, with a 25mg dose of COMP360 demonstrating a statistically significant (p<0.001) and clinically relevant treatment difference against the 1mg dose of COMP360 in reducing depressive symptom severity after three weeks.

At the beginning of 2023, we commenced our Phase 3 program evaluating our COMP360 psilocybin treatment in TRD. The Phase 3 program is composed of two pivotal trials, each with a long-term follow-up component. The pivotal program design is as follows:

• Pivotal trial 1 (COMP005) (n=255): a single dose (25mg) monotherapy compared with placebo. This trial is designed to replicate the treatment response seen in our Phase 2b trial (n=233). We expect to report top-line data in the fourth quarter of 2024.

• Pivotal trial 2 (COMP006) (n= 568): a fixed repeat dose monotherapy using three dose arms: 25mg, 10mg and 1mg. This trial is designed to investigate whether a second dose can increase treatment responders and whether a second dose can improve responses observed in our Phase 2b trial and to explore the potential for a meaningful treatment response from repeat administration of COMP360 10mg. We expect to report top-line data by mid-2025.

• The primary endpoint in both pivotal trials is the change from baseline in the MADRS (Montgomery-Åsberg Depression Rating Scale) total score at week 6.

Beyond TRD, we have ongoing Phase 2 trials in PTSD and anorexia nervosa. We also provide support to research institutions conducting investigator-initiated studies, or IISs, with COMP360 psilocybin in areas of serious unmet need. These are signal-generating studies that we believe may provide signals for new potential indications that we can explore further and may bring into our development pipeline. For example, the University of California San Diego School of Medicine completed an IIS of COMP360 psilocybin in anorexia nervosa and presented positive data from this study at the Society of Biological Psychiatry Annual Meeting in May 2022. Based on the data generated in this IIS, we decided to proceed with a Phase 2 clinical trial for anorexia nervosa. Additional IIS studies are underway in a number of other indications including autism, suicidal ideation and severe TRD.

The need for innovation in mental health care is significant, given that the current treatment paradigm is ineffective for millions of people. Our vision is a world of mental wellbeing – a world in which mental health isn’t simply the absence of

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mental illness, but the ability to flourish. We want to help reduce the stigma surrounding mental health, to acknowledge that “everyone has a story,” and to create a system of care for all who are not helped by the existing system and existing therapies.

Our Strategy

Our mission is to accelerate patient access to evidence-based innovation in mental health. Key elements of our strategy to achieve this include:

•Advance our Phase 3 registrational program for our investigational COMP360 psilocybin treatment for the treatment of TRD. In 2021, we completed a randomized, controlled Phase 2b clinical trial in 233 TRD patients, in 22 sites across North America and Europe and a Phase 2 exploratory trial in 19 TRD patients. We announced positive top-line results from these trials in November and December 2021. The results from our Phase 2b clinical trial were published in the New England Journal of Medicine in November 2022. We commenced our Phase 3 registrational program and expect to report top-line data from our COMP005 study in the fourth quarter of 2024 and from our COMP006 study in mid-2025.

•Expand our investigational COMP360 psilocybin treatment into new indications. We believe that our investigational COMP360 psilocybin treatment may confer beneficial effects in other areas of high unmet need in mental health. We are conducting Phase 2 trials evaluating COMP360 psilocybin treatment in PTSD and anorexia nervosa. In addition, we are generating preclinical and clinical data to further our mechanistic understanding and explore the potential benefits of our COMP360 psilocybin treatment in other indications. We are performing some of these studies ourselves and some through collaborations with academic institutions, including through IISs. The outcomes of these studies will help inform which indications we may pursue.

•Explore other compounds to address areas of unmet need. Our internal discovery efforts are focused on value propositions that meet unmet patient needs and ensure differentiation against our COMP360 psilocybin treatment and the broader competitive landscape. Ongoing research on prodrug development has led to a number of potential candidate leads being identified that we plan to continue through further research-based development. The outcomes of these studies will help inform which compounds and drug candidates we may pursue.

•Maximize the reach and value of our investigational COMP360 psilocybin treatment by creating a new model for mental health care. We retain global development and commercialization rights for our investigational COMP360 psilocybin treatment and are developing a commercial rollout plan in the event we are granted approval from regulatory authorities, working with payors to enable reimbursement and with health systems to enable broad patient access. We engage with the broader healthcare ecosystem to drive innovation in research in mental health and inform models for delivery for COMP360 psilocybin, including to gather evidence to optimize our therapy model, training of therapists, and prototype digital technology solutions to improve patient experience and outcomes. We established a Center of Excellence, with The Sheppard Pratt Institute for Advanced Diagnostics and Therapeutics, in Baltimore, Maryland and The Center for Mental Health Research and Innovation with King’s College London and South London and Maudsley NHS Foundation Trust, or SLaM. Recently, we entered into research collaborations with Hackensack Meridian Health, a leading not-for-profit health care organization in New Jersey, and Greenbrook TMS, which operates through 130 company-operated treatment centers throughout the United States, to research and investigate models for the delivery of scalable, commercial COMP360 treatment within healthcare systems, assuming FDA approval.

•Use digital technology to improve access to and the impact of our investigational COMP360 psilocybin treatment. We are exploring ways to use digital technology to make our treatment delivery model more scalable, and to improve patient experience and outcomes. We plan to build upon the technologies we are deploying during our clinical trials, including our myPathfinder app, which is designed to help patients prepare for their COMP360 psilocybin treatment experience, and Therapist COMPanion a web-based “shared knowledge” interactive platform to complement our face-to-face and clinical therapist training. We are also developing Chanterelle, our AI (which we refer to as Augmented Intelligence as well as Artificial Intelligence) and analytics solution through which we aim to generate novel insights into the predictors and drivers of therapeutic outcomes, the patient experience, and therapist performance. We believe this may enable us in the future to offer a personalized, preventative and predictive care model.

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Our Pipeline

The following table summarizes the status of our pipeline:

Investigational COMP360 Psilocybin Treatment

We are developing our investigational COMP360 psilocybin treatment for the treatment of a range of mental health conditions, with an initial focus on TRD. There is a large unmet need for new therapies to improve the response rate and durability of response for patients suffering with TRD. We believe our investigational COMP360 psilocybin treatment, if successfully developed and approved, represents a promising therapeutic option for TRD, as well as potentially for other mental health and neurological conditions, including PTSD and anorexia nervosa.

TRD

TRD is a subset of MDD. MDD is a condition characterized by a persistent feeling of sadness and heightened negative emotions. It is considered a unipolar condition, suggesting a distinction between MDD and bipolar depression, the latter of which is often associated with an emotional state fluctuating between depression and hypomania or mania. MDD is a chronic, relapsing, recurring and serious mental health condition associated with high mortality rates, morbidity and diminished quality of life. The World Health Organization, or WHO, estimates as of 2023 that approximately 280 million people worldwide are suffering with MDD.

Due to the limitations of existing treatments, nearly one-third of those suffering with MDD are not adequately helped after two or more existing depression treatments. This condition is referred to as TRD. TRD has greater economic and societal cost than non-TRD MDD. TRD patients are often unable to perform daily tasks, are more likely to receive disability or welfare benefits and more frequently have co-occurring conditions compared with non-TRD MDD patients. In several studies, the direct medical costs for patients with TRD were significantly higher than those for non-TRD MDD patients, driven by, among other factors, increased rates of hospitalization and longer average hospital stays. Patients with TRD have a higher all-cause mortality compared with non-TRD MDD patients.

Patients suffering with depression are treated through a variety of approaches, each of which can have significant shortcomings in certain subsets of patients. Most pharmacotherapies for depression employ the same mechanism of action, targeting the modulation of the brain’s neurotransmitter monoamine levels, and have exhibited limited efficacy in a significant portion of patients and can result in high relapse rates. There are only two pharmacotherapies specifically approved for TRD in the US: esketamine, and a combination of olanzapine (an atypical antipsychotic) and fluoxetine (a selective serotonergic reuptake inhibitor). Esketamine was approved in 2019 by the FDA. Mixed efficacy and limited durability were observed in clinical trials, as well as potential side effects, including dissociation and cognitive impairment. The olanzapine-fluoxetine combination has also shown mixed efficacy and can commonly lead to side effects such as dizziness, drowsiness and weight gain. In addition to pharmacotherapies, various forms of somatic intervention are also used, although these treatments tend to be invasive and/or onerous, and there is limited data supporting their long-term benefit. Psychotherapy is another common treatment approach, but it requires a significant time commitment and is subject to large variability in availability and administration. Despite the range of treatments and therapies currently available for depression, patients suffering with TRD

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continue to be underserved, prolonging a significant health, social and economic burden. We believe patients suffering with TRD need a paradigm-shifting treatment that can deliver rapid and sustained relief of their depression.

The following table, which is based on data from the Star*D trial conducted by the National Institute of Mental Health in 2006, indicates the worldwide estimated patient populations suffering with new onset MDD, persistent MDD and TRD, and the primary treatment options available.

Treatment pathway stage	New onset depression Major depressive disorder (MDD)	Persistent depression Major depressive disorder (MDD)	Treatment-resistant depression (TRD)
Line of therapy	First line	Second line	Third line +
Patients (worldwide)	320 million	200 million	100 million (~33% of total)
Available treatments	•Antidepressants •Psychological interventions eg, CBT*	•Antidepressants •Antidepressant combinations •Psychological interventions	•Antidepressants •Augmentation therapy (antidepressants, mood stabilizers, anticonvulsants, atypical antipsychotics. esketamine) •Ketamine •Somatic therapy (rTMS*, tDCS*, ECT*, DBS*) •High-intensity psychological interventions
% relapse	60-70%	50-75%	80-90%

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*CBT = cognitive behavioral therapy; rTMS = repetitive transcranial magnetic stimulation; tDCS=transcranial direct current stimulation; ECT=electroconvulsive therapy; DBS=deep brain stimulation. Table adapted from Rush, A. J., Trivedi, M. H., Wisniewski, S. R., Nierenberg, A. A., Stewart, J. W., Warden, D., ... & Fava, M. (2006). Acute and longer-term outcomes in depressed outpatients requiring one or several treatment steps: a STAR* D report. American Journal of Psychiatry, 163(11), 1905-1917.

Limitations of Existing Therapies for Depression

Because depression has 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, such as antidepressants and psychotherapy, respectively, are well-established and efficacious for a subset of MDD patients. However, many patients experience relapses. Clinicians lack high-quality evidence and often rely on a trial-and-error approach, course correcting as patients experience these relapses or difficult side effects. Experts are beginning to recommend a shift to more multi-modal treatments where different types of therapy are delivered concomitantly (i.e., a mix of pharmacotherapy, psychological/behavioral, and device interventions).

Patients suffering with TRD are treated through a variety of approaches, each of which is associated with significant shortcomings. Consequently, there remains a need for a fast-acting, tolerable treatment that provides a durable response. Despite the condition’s largely heterogeneous nature, most pharmacotherapies for depression use the same mechanism of action, targeting the modulation of the brain’s neurotransmitter monoamine levels. As evidenced by the low response and high relapse rates, these treatments are not effective for a large number of patients. Various forms of somatic intervention are also used, although there is limited data supporting their long-term benefit. Esketamine, a TRD therapy, demonstrated mixed efficacy in its pivotal clinical trials, with rapid relapse rates even with adjunctive antidepressants and protracted withdrawal reactions. We believe currently available options do not adequately meet the needs of patients suffering with TRD and there is a significant need for a new therapeutic approach.

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The following table includes representative ranges and approximate costs in the U.S. market for existing treatments of depression as well as their methods of delivery.

Therapy	Route	Frequency and duration	Strategy ¹	Reimbursement ²	Approximate annual cost per patient ³
Antidepressants: SSRI/SNRI*	Oral	1/day, chronic	Mono/ Adjunctive therapy	Broad	$12 - $8,300
Atypical antipsychotics	Oral	1/day - chronic	Adjunctive therapy	Broad	$55 - $20,700
CBT	Face-to-face or online	10-20 sessions, 3-4 months	Mono/ Adjunctive therapy	Broad	Averaging $1,000
Esketamine	Intranasal	25 - 50 sessions/year, under supervision of a healthcare professional	Adjunctive therapy	Limited	$33,000 - $45,000
Ketamine**	Intravenous	25 - 30 administrations	Adjunctive therapy	No	$2,500 - $5,000
rTMS	Magnetic brain stimulation without anesthesia	5 sessions/ week, 6 - 7 weeks (30 - 35 sessions)	Mono/Adjunctive therapy	Limited	$6,000 - $12,000
ECT	Electric brain stimulation under anesthesia	3 sessions/ week, 4+ weeks	Mono/Adjunctive therapy	Limited	$15,000 - $30,000
VNS	Electric pulses sent to the brain	Duration varies from patient to patient – stimulator must first be implanted and given at a starting low dose every 5 minutes from day to night	Mono/Adjunctive therapy	Limited	$40,000 - $45,000 for surgical implementation (excluding costs of post-operative device adjustments)
DBS	Electrical impulses to the brain through implanted electrodes	3-6 hour operations; follow up visits	Mono/Adjunctive therapy	Limited	$200,000 - $250,000 for surgical implementation (excluding costs of battery replacements required every 12-24 months costing ~$95,000 for hardware replacement and surgery)

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Key: orange: established common pharmacotherapies for depression; blue: common psychotherapy for depression; grey: novel pharmacotherapies for depression; green: somatic therapies for depression

*SSRI = selective serotonergic reuptake inhibitor; SNRI =serotonergic norepinephrine reuptake inhibitor; ** Ketamine is prescribed off-label and is not approved for the treatment of depression

1. Based on a year of treatment, 150mg/day, augmentation with fluoxetine for U.S. or citalopram for UK 2. Government reimbursement or private insurance coverage; 3. Assumes one treatment course over the year, direct treatment cost only (not related provider cost or total healthcare costs) and where applicable, estimated cost range includes branded and generic treatments.

Pharmacotherapies

There are five main categories of antidepressants available on the market. These are selective serotonergic reuptake inhibitors, or SSRIs, and serotonergic norepinephrine reuptake inhibitors, or SNRIs, atypical antidepressants, monoamine

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oxidase inhibitors, or MAOIs, and tricyclic antidepressants, or TCAs. These are frequently used in first- and second-line treatment of depression and can also be used after this point. Studies have shown that approximately 50% of patients are not helped by their initial antidepressant treatment. This figure rises to as high as 70% for subsequent treatments.

Currently approved antidepressants have significant limitations, including delayed onset of action, poor therapy adherence rates and various side effects. The onset of action for the most commonly used antidepressants is typically between two and three weeks. Adherence levels are relatively low, with approximately 50% of individuals in primary and psychiatric care not adhering to their prescribed antidepressant medication.

There is limited evidence to effectively guide clinical decisions following non-response or partial response to first-line antidepressant medications. Recommended treatment approaches include optimizing the current antidepressant dose or switching to an antidepressant in the same or different class. Partial response or lack of response thereafter is recommended to be addressed by combining antidepressants from different pharmacological classes, or augmenting with an alternative medication, primarily with atypical antipsychotics, but also mood stabilizers, anticonvulsants, thyroid hormones and stimulants, and N-methyl-D-asparate, or NMDA, antagonists.

Antipsychotics, such as olanzapine, quetiapine and aripiprazole are typically used as adjunctive therapies when there is a lack of notable efficacy with an antidepressant. There is an approved combination of olanzapine and fluoxetine (an SSRI) for TRD. However, using antidepressants and antipsychotics together can have serious side effects, such as weight gain, other metabolic complications, sedation, extrapyramidal side effects (movement disorders), and QTc prolongation, which means the ventricles of the heart take longer than usual to recharge between beats.

Psychotherapies (Including Cognitive Behavioral Therapy, or CBT)

Psychotherapy is a form of talk therapy often recommended as first-line treatment in mild depression and often used as adjunctive therapy for MDD patients. Two frequently used psychotherapies for depression are CBT and interpersonal therapy, or IPT. CBT focuses on changing negative thought and behavior patterns. IPT also looks at negative thoughts and behaviors, but only as they apply to interpersonal relationships and social functioning. The incremental efficacy of psychotherapy in more severe cases and in later lines of treatment remains questionable. Psychotherapeutic approaches can be effective for many individuals but require a significant time commitment from patients and are subject to variability in their availability and delivery.

Esketamine/Ketamine

Ketamine is an NMDA receptor antagonist that has been used for several decades in sedation, anesthesia and chronic pain. The S-enantiomer of ketamine, esketamine, is administered intranasally as a spray and has been approved by the FDA to treat TRD (2019) and depressive symptoms in adults with MDD with acute suicidal ideation or behavior (2020). There are mixed efficacy results associated with the use of esketamine. Ketamine and esketamine require multiple administration sessions and are associated with a high abuse potential. Esketamine treatments typically need to be frequently administered, in a controlled environment under medical supervision. This frequency makes administration costly for payors and burdensome for patients.

Somatic Therapies

Patients who suffer with severe TRD and have tried several courses of antidepressants are often treated with resource-intensive somatic therapies like electroconvulsive therapy, or ECT, repetitive transcranial magnetic stimulation, or rTMS, vagal nerve stimulation, or VNS, and deep brain stimulation, or DBS. These therapies are generally administered in inpatient settings. Somatic and device-related interventions like ECT and VNS are associated with significant adverse reactions and interventional concerns, such as use of general anesthesia and memory loss in the case of ECT, and surgical intervention and infection risk with VNS implantation. Limitations of rTMS include inadvertent seizures, pain, face twitching and application discomfort. Similarly, DBS has the potential to cause pain and seizures as well as a high risk of infection due to the invasiveness of the surgical procedure. These treatments are typically reserved for patients who have not been helped by other treatments, and are characterized as high-cost treatment options with reimbursement limited for a subset of these therapies.

Despite the range of treatments and therapies available for MDD, patients suffering with TRD continue to be underserved, prolonging a significant health, social and economic burden. We believe patients suffering with TRD need a paradigm-shifting treatment that can deliver rapid and sustained relief of their depression.

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Post Traumatic Stress Disorder

PTSD is a serious mental health condition that can impact quality of life and lead to diminished cognitive and psychosocial functioning, fractured relationships, inability to maintain employment, substance abuse, high healthcare utilization costs, increased depression, and suicide risk. PTSD can occur in people who have experienced or witnessed a traumatic event, such as a natural disaster, serious accident, war or rape. People who experience PTSD may relive their traumatic experience(s) through nightmares and flashbacks, have difficulty sleeping, and feel detached or estranged. Some people with PTSD experience symptoms immediately after the event, while for others symptoms may appear years later. It is estimated that approximately 311 million people will experience PTSD at some point during their lives. Only 20 -30% of patients treated with currently approved pharmacological interventions for PTSD will reach full remission.

Anorexia Nervosa

Anorexia nervosa is a serious mental health condition characterized by severe restriction of calorie intake and a preoccupation with weight and shape. People with anorexia nervosa generally restrict their caloric intake, types of food they eat, and might engage in purging behaviors, such as strenuous exercise, vomiting, and laxatives misuse. It carries the highest mortality rate of all psychiatric disorders. This high mortality rate is explained in part by the physical complications (muscle and bone problems, such as osteoporosis; damage to the brain leading to seizures and memory issues; and heart problems including heart failure) and in part by an increased rate of suicide; approximately 20% of deaths in anorexia nervosa are thought to result from suicide. Approximately 3.9 million people globally suffer from anorexia nervosa as of 2019; it has a lifetime prevalence of approximately 4% in females. There are no pharmacological treatments approved to treat anorexia nervosa and psychological treatments have relapse rates as high as 52%.

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Psilocybin Therapy

Mechanism of Action of Psilocybin

There is an accumulating body of evidence that psilocybin may have beneficial effects on depression and other mental health conditions. We believe the benefits of psilocybin are largely derived from its mechanism of action. As shown in the graphic below, by activating a distinct set of receptors in brain areas critical to mood and cognition, psilocybin acts to induce a range of downstream effects that may have important, sustained effects on brain function. In this way, evidence of the molecular, cellular, and systemic effects of psilocybin in the CNS supports the potential for psilocybin in the treatment of mental health conditions.

1. Stimulation of 5-HT2A receptors results in downstream cascades via G-protein signaling. 2. Altered extracellular release of dopamine leads to enhanced positive mood. 3. Down-regulation of the default mode network, or DMN, and de-synchronization of cortical activity as well as the emergence of new patterns of functional connectivity across the brain. 4. Sustained cellular changes leading to neuroplasticity and “window of opportunity” for therapy.

Molecular Effects of Psilocybin: Partial Agonism of Serotonin Receptors

At the molecular level, psilocybin is rapidly metabolized to its active metabolite psilocin, which is a partial agonist at several 5-hydroxytryptamine (serotonin) 2A, or 5-HT, receptors, also known as serotonin receptors, including 5-HT2A, 2C, and 1A receptors. This means that psilocin binds to and activates these receptors, all of which are expressed in neurons in different areas of the CNS. In particular, many of the prominent acute effects of psilocybin, such as changes in emotion and cognition, are thought to be mediated by 5-HT2A receptor stimulation, an interpretation that is supported by the fact that blocking the 5-HT2A receptor prevents the psychedelic effects of psilocybin in humans. This mechanism of 5-HT2A receptor stimulation is also implicated as a possible component of the antidepressant action of SSRIs, although these operate by inhibiting reuptake of serotonin by presynaptic neurons. In contrast, psilocin is believed to initiate an antidepressant effect by directly activating this receptor. The relevance of 5-HT2A receptors in modulating depressive symptoms may also be supported by the fact that these receptors are abundantly expressed in multiple areas of the brain that have important roles in regulating cognitive and emotional processing. For instance, 5-HT2A receptors are predominantly expressed in cortical pyramidal neurons, the most abundant type of neuron found in the human cerebral cortex, and thus may be implicated in executive function. Additionally, 5-HT2A receptors are expressed in other key regions of the brain, like the hippocampus and nucleus accumbens, which are associated with crucial biological functions like memory and reward processing, respectively.

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Cellular Effects: Activation of Downstream Signaling Cascades

Activation of 5-HT2A receptors by agonist ligands such as psilocin can modulate a number of downstream signaling cascades to alter the structure and function of neurons, which are the primary signaling components of the CNS. The 5-HT2A receptor is a G-protein coupled receptor, which means that it predominantly relays signals through a family of proteins called G-proteins. Specifically, the main signaling cascade downstream of 5-HT2A receptors occurs via the Gαq/11 protein and leads to increased intracellular calcium release within the cell. In turn, this may promote neuron growth and function. However, non-canonical 5-HT2A receptor signaling cascades specific to certain cell or tissue types may also exist, as there is evidence of certain downstream effects of psychedelic agonists occurring via the Gαi/o protein, which typically downregulates signaling pathways related to neurotransmitter release, for example, within neurons. This diverse range of cellular signaling cascades that may be modulated by psilocin likely underlie some of the local circuit-level effects of the drug.

Local Circuit-Level Effects: Neurotransmitter Release and Neuroplasticity

The consequences of 5-HT receptor signaling cascades as modulated by psilocin include (i) changes in activation of neurons in the brain, (ii) neuroplasticity, and (iii) alteration of neurotransmitter release. The activation of neurons, or depolarization, corresponds to positive ions flowing into these cells, which ultimately drives signal transmission and communication between neurons.

Neuroplasticity refers to the ability of the nervous system to reorganize its structure, function, and connections. This can involve the generation of new neurons, changes in neuron morphology and connectivity, and neurobiochemical changes in receptor and neurotransmitter levels. In particular, the expression of immediate early genes, or IEGs, such as Early Growth Receptor-1, or EGR-1 and Early Growth Receptor-2, or EGR-2, is induced by psilocin. IEGs are genes activated in response to external stimuli and are associated with depolarization. IEGs produce transcription factors that may cause wider changes in gene regulation and, in turn, could enable longer-term neuroplastic changes through structural and connectivity changes at the synapse. The fact that EGR-1 and EGR-2 appear to be induced specifically by psychedelic compounds suggests that these genes could be relevant to the acute and sustained effects of these drugs.

Alterations in neurotransmitter release are another local circuit-level consequence of psilocin that may be relevant to its psychoactive and mood effects. Specifically, evidence from rodent studies suggests that psilocybin may alter extracellular release of serotonin and dopamine in brain areas such as the prefrontal cortex. By virtue of the extracellular neurotransmitter release changes in certain brain areas, which have established roles in, for example, executive function, psilocybin may drive positive mood effects.

Systemic Effects: Changes in Brain Activity and Functional Connectivity

At the systemic level, psilocybin has been shown to alter the synchronicity of neuronal activation within and between different brain networks, during the psychedelic experience and afterwards. One network that has displayed altered functioning after psilocybin treatment in recent studies is the default mode network, or DMN, a network of brain areas that shows increased activation during self-referential mental activity and recollection of prior experiences and reduced activation during attention-demanding tasks. During the acute experience, psilocybin appears to temporarily reduce synchronicity of areas within the DMN, whereas connectivity between other brain areas and networks is substantially increased.

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The below figure is a visualization of the acute changes in brain network connectivity when healthy volunteers were administered with placebo (left) or psilocybin (right). Lines represent connections between or within brain networks (shown as nodes), with the width of those lines representing the weight of each connection. The size of each node corresponds to the sum of its weighted connections. Colors represent communities of networks or regions that are more commonly connected to one another than networks in different communities.

Simplified Visualization of the Acute Changes in Brain Network Connectivity
	Placebo	Psilocybin

Study analyzed fMRI (functional magnetic resonance imaging) data from healthy volunteers to compare resting-state functional brain connectivity after intravenous infusion of placebo and psilocybin. Adapted from Petri et al, 2014.

On the day after these acute effects, individuals administered with psilocybin may exhibit increased synchronicity within the DMN, as well as changes between areas of the DMN and other brain regions. These brain network alterations may indicate the emergence of novel patterns of connectivity upon decoupling of the DMN and could lead to longer-term changes, such as altered emotional processing, that may ultimately affect behavior.

Investigational COMP360 Psilocybin Treatment Clinical Development Programs

COMP360 is our proprietary psilocybin formulation that includes our pharmaceutical-grade polymorphic crystalline psilocybin, optimized for stability and purity. Our investigational COMP360 psilocybin treatment comprises administration of our COMP360 with psychological support from specially trained therapists with specific professional and educational qualifications. We are conducting clinical trials in TRD, PTSD and anorexia.

COMP360 Psilocybin Treatment Protocol

Our psilocybin treatment comprises administration of COMP360 with psychological support from specially trained therapists. Psychological support is designed to facilitate patient safety and optimal therapeutic outcomes. Our psychological support model is manualized and standardized for consistent delivery across all our trial sites. Our model is delivered over three different phases: preparation, the COMP360 administration session, and integration.

Our psilocybin treatment takes place over a period of several weeks, and comprises:

•Preparation: The objectives of the preparation sessions are to establish a therapeutic alliance between the patient and therapist, and to demonstrate and practice the skills of self-directed inquiry and experiential processing, which we believe are critical for embracing the psychedelic experience in the psilocybin administration session. We have created an online preparation platform and MyPathfinder app for patients where they can learn more about what to expect from the experience and how to prepare for it.

•Psilocybin administration: A psilocybin administration session lasts approximately six to eight hours and a therapist and assisting therapist are present throughout the session. The therapist’s goal during the session is to establish psychological safety, minimizing anxiety and encouraging openness to all emerging experiences. The session takes place in a room designed to be ambient, comfortable and calming. Patients wear eyeshades to help them focus internally, lie on a bed, and listen to a carefully curated music playlist through a high-quality sound system and earphones. After the acute effects of psilocybin subside, patients are evaluated for safety and discharged.

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•Post-administration integration: The objectives of integration sessions are to help patients process the range of emotional and physical experiences facilitated by the psilocybin session and to generate insights that can lead to cognitive and behavioral changes. We believe psilocybin treatment can give patients a sense of agency, whereby they feel separate from their symptoms and empowered to make changes in their lives.

Therapists in our clinical trials are required to have an active unrestricted professional license to practice as a clinical psychologist, psychiatrist, social worker or mental health counselor. Therapists must also meet the required training and credentialing standards to practice psychotherapy in their region. Those who have active, unrestricted professional licenses as mental health nurses or any other mental health professional may be eligible to practice as a therapist in our clinical trials, subject to fulfilling criteria around equivalent clinical experience and psychotherapy training as the professionals listed above.

Our method of psychological support is based on our current understanding of psilocybin’s potential to generate new insights and perspectives leading to reduced rigidity in thinking. This modification of thought patterns can be uncomfortable or anxiety-provoking. Therapists refrain from intervening with the patient’s experience, unless required for safety reasons. Such an approach differs from some forms of psychotherapy which can be more directive and interventional. Our therapist training program sets out a formal and scalable methodology for psychological support delivered during the psilocybin treatment. It will continue to evolve as we progress COMP360 psilocybin treatment through clinical trials, but this manualized approach to the training program is an important first step in reducing variation in psychological support and setting out a framework for training and evaluation of this support. Details of the program were published in February 2021 in the peer-reviewed journal Frontiers in Psychiatry.

Phase 2b Trial of Our COMP360 Psilocybin Treatment in TRD

In 2021, we completed a Phase 2b international multi-site, randomized, controlled, double-blind, dose-finding clinical trial to assess the safety and efficacy of active doses of COMP360 (10mg or 25mg) compared with 1mg COMP360, administered with psychological support, in 233 patients suffering with TRD, across 22 trial sites in 10 countries in North America and Europe. In November 2022, The New England Journal of Medicine, the world’s leading peer-reviewed medical journal, published the positive results from our Phase 2b trial of COMP360 psilocybin treatment for TRD.

Trial Design

Patients who are on serotonergic medications were expected to taper off their medicine at least two weeks prior to the baseline (Day -1) visit. Prior to administration, patients received at least one, and up to three, preparatory sessions with an assigned therapist, in order to be informed and prepared for the COMP360 psilocybin session. During the COMP360 psilocybin session, a single dose of COMP360 was administered to patients. The objective was to provide a safe and supportive environment during the session. Patients received two post-administration integration sessions with their therapists in which the psychedelic experience was discussed. Patients were followed up for 12 weeks, with a visit the day after administration followed by an additional six visits, weekly for the first three weeks, and every three weeks for the remaining nine weeks.

Primary, secondary and exploratory endpoints

The primary endpoint of this trial was the change in the MADRS total score from baseline to week 3. MADRS is assessed by independent raters in native language and is a widely accepted assessment of mood disorders. This variable was also being analyzed for change from baseline to Day 2, weeks 1, 6, 9 and 12. This Phase 2b clinical trial was powered to capture a statistically significant reduction in MADRS.

Secondary endpoints of the trial included:

•The proportion of participants with a response (defined as a ≥50% decrease in MADRS total score from baseline) at week 3;

•The proportion of participants with remission (defined as a MADRS total score ≤10) at week 3;

•The proportion of participants who had a sustained response at week 12. Sustained response was defined as the proportion of patients fulfilling response criteria at any visit up to and including week 3, that also fulfills response criteria at all subsequent visits up to and including week 12; and

•Time to event measures: including restarting of antidepressant medication for any reason, suicidality, hospitalization for depression, and relapse from a previous response to COMP360 psilocybin treatment.

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Safety and tolerability of COMP360 in patients suffering with TRD was assessed based on AEs, vital signs, clinical laboratory assessments, ECG findings and suicidal ideation/behavior (measured using the Columbia-Suicide Severity Rating Scale, or C-SSRS score, at all visits).

The trial also assessed exploratory endpoints including, but not limited to, quality of life (EQ-5D-3L), functional impairment (Sheehan Disability Scale, SDS), psychosocial functioning (Work and Social Adjustment scale, WSAS), cognition (Digit Symbol Substitution Test, DSST), anxiety (Generalized anxiety disorder, GAD-7), and self-reported depression severity (QIDS-SR-16).

Enrollment Criteria

We recruited a total of 233 adult patients with TRD into the trial. We define TRD patients as those who meet Diagnostic and Statistical Manual of Mental Disorders, 5th Edition, or DSM-5, diagnostic criteria for a single or recurrent episode of MDD without psychotic features, who have not responded to an adequate dose and duration of two, three, or four pharmacological treatments for the current episode of depression.

Clinical findings

The 25mg group vs the 1mg group showed a -6.6 difference on the MADRS depression scale at week 3 (p<0.001). The 25mg group demonstrated statistical significance on the MADRS efficacy endpoint on the day after the COMP360 psilocybin administration, day 2 (p=0.002). The 10mg vs 1mg dose did not show a statistically significant difference at week 3. The MADRS was assessed by independent raters who were remote from the trial site, and blind to intervention and study design, effectively creating a triple blind.

Change from baseline in MADRS total score

MADRS = Montgomery-Åsberg Depression Rating Scale

At week 3, 36.7% (29 patients) in the 25mg group were responders (defined as a ≥50% decrease in MADRS total score from baseline), compared with 17.7% (14 patients) in the 1mg group. Furthermore, 29.1% (23 patients) in the 25mg group were in remission (defined as a MADRS total score ≤10) at week 3, compared with 7.6% (6 patients) in the 1mg group. At

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week 12, 20.3% (16 patients) in the 25mg group were sustained responders (defined as meeting the MADRS response criteria at week 3 and week 12, and at least at one visit out of week 6 and week 9) compared with 10.1% (8 patients) in the 1mg group.

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MADRS response and remission rates

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MADRS = Montgomery-Åsberg Depression Rating Scale

MADRS sustained response rates

MADRS = Montgomery-Åsberg Depression Rating Scale. Number of sustained responders stated in bar.

Patients meeting the MADRS response criteria at any visit up to and including week 3 and at all subsequent visits up to and including at week 12, and who did not start any new treatments for depression.

As well as looking at clinician-rated depression severity on the MADRS, the trial explored other aspects which are recognized as being important for patients with TRD - and essential to recovery - including positive and negative affect, anxiety, self-rated depression severity, quality of life, functioning and cognition. These exploratory measures also showed that patients in the 25mg dose group of COMP360 psilocybin treatment reported benefits on those measures over those in the 1mg group. On the Positive and Negative Affect Schedule measuring positive and negative affect, patients in the 25mg group had a higher increase in positive affect (e.g., including feeling interested, excited, strong) and a greater decrease in negative affect (including feeling distressed, upset, afraid) on the day after COMP360 administration and at the questionnaire’s final administration at week 3. On scales measuring anxiety (the Generalized Anxiety Disorder – 7 item scale), self-rated depression (QIDS-SR-16) and functioning (Sheehan Disability Scale and Work and Social Adjustment Scale), a greater improvement was also shown at week 3 by patients in the 25mg group compared with the 1mg group. A post-hoc analysis of the 16 sustained responders in the 25mg group found that changes in quality of life, self-reported depression severity, and functioning, were clinically meaningful, with mean scores for these patients returning to “normal” levels and maintained to 12 weeks, the end of the trial. Additionally, sustained responders were found to have clinically meaningful increases in positive affect from baseline at day 2 and week 3.

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COMP360 was generally well tolerated, with more than 90% of treatment-emergent adverse events (TEAEs) being mild or moderate in severity and greater than 77% of TEAEs occurring on the day of administration being resolved on the same day or the next day. 179 patients reported at least one TEAE; the most common TEAEs across treatment groups (>10% overall

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incidence) were headache, nausea, fatigue, and insomnia. There were 12 patients who reported treatment-emergent serious adverse events (TESAEs). These TESAEs included suicidal behavior, intentional self-injury, and suicidal ideation, which are regularly observed in a TRD patient population. Two thirds of the patients had previous thoughts of wishing to be dead, as assessed by a suicidality scale completed during patient screening; this included all patients reporting one of these adverse events, meaning that patients who experienced these events during the trial had said in patient screening that they had had suicidal thoughts prior to the trial.

•There was no difference between the three groups post-administration in scores from item 10 on the MADRS, which measures suicidality and was assessed by a blinded remote rater; mean scores across treatment groups were lower than baseline at all subsequent time points

•27 of the TEAEs of suicidal ideation, suicidal behavior and intentional self-injury occurred across 17 patients, with seven patients in the 25mg group, six in the 10mg group, and four in the 1mg group

•14 of these events of suicidal ideation, suicidal behavior and intentional self-injury were reported as TESAEs; these occurred across nine patients, with four patients in the 25mg group, four patients in the 10mg group, and one in the 1mg group

•The majority of these TESAEs (10 events out of 14) occurred at least one week after the COMP360 psilocybin session

•All suicidal behaviors occurred at least one month after the psilocybin treatment session and all patients reporting these events were non responders at their last assessment prior to the event or at the time of the event

Overall, 209 patients completed the study; there were five withdrawals from the 25mg group, nine from the 10mg, and 10 from the 1mg.

Phase 2 Study of COMP360 Psilocybin Treatment as Adjunct to SSRI Antidepressants

In addition to our completed Phase 2b trial, we have also completed a Phase 2 trial of the safety and efficacy of COMP360 in TRD patients when administered as an adjunct to SSRIs. Results of this study were published in the Nature journal Neuropsychopharmacology in July 2023.

This open-label study included 19 patients from clinical sites in Ireland and the United States. The primary endpoint was the change in baseline MADRS total score at 3 weeks in patients having 25mg COMP360 psilocybin treatment given in augmentation with their existing SSRI antidepressant regimen.

Clinical Findings

The baseline MADRS score of patients entering the study was 31.7, representing moderate to severe depression. At week 3, 8 of the 19 patients (42.1%) were responders and all 8 were also remitters. The mean reduction from baseline observed in MADRS total score was 14.9 at week 3. There was a rapid response from day 2 to week 3 after COMP360 therapy, which is consistent with the Phase 2b result.

Change from baseline in MADRS total score

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COMP360 psilocybin treatment using a 25mg dose also showed overall signals of improvement in most other measures including improvement in anxiety, clinician and self-rated depressive symptoms, and positive and negative affect.

25mg COMP360 psilocybin treatment was generally well-tolerated when it was administered simultaneously with the patient’s existing SSRI treatment. There were no TEAEs classed as serious (life threatening, leading to disabilities, hospitalization or in general medically significant) and no TEAEs related to suicidal ideation or behavior or intentional self-injury.

Long-Term Phase 2 Study

During 2022, we completed a long-term follow-up study of 66 participants who took part in our Phase 2b trial. Of the 66 participants, 22 participants were in the 25mg group, 19 participants were in the 10mg group, 17 participants were in the 1mg group and 8 participants were in the 25mg plus SSRI group. The primary endpoint of this Phase 2b follow-up study was the median time to a new depressive event. The pre-specified primary analysis was of the median time for such an event for all participants in our Phase 2b trial, not only those who took part in the long-term follow-up study. The median time to a new depressive event was 92 days for the COMP360 25mg group compared to 86 days for the 10mg group and 62 days for the 1mg group.

In an additional post-hoc analysis to support the primary endpoint only including those participants from our Phase 2b study who took part in the long-term follow up study (COMP004) the median time to such an event was longer (189 days) for the COMP360 25mg group compared to the 10mg group (43 days) and the 1mg group (21 days) (patients entering from our Phase 2b study).

Twenty-seven or 40.9% of participants had an adverse event that was ongoing as of, or started, after week 12. In addition, a lower proportion of participants started new treatments for depression in the 25mg and 10mg arm compared to the 1mg arm. Suicidality was recorded as an adverse event twice in the 25mg group, twice in the 10mg group, and once in the 1mg group. The outcomes of the long-term follow-up study informed the design of our Phase 3 registrational program, including investigating whether a second administration of COMP360 may achieve improved durability, response and remission outcomes.

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Phase 3 Registrational Program and Supportive Studies

We commenced our Phase 3 program evaluating our COMP360 psilocybin treatment in TRD. The Phase 3 program is composed of two pivotal trials, each with a long-term follow-up component. The pivotal program design is as follows:

• Pivotal trial 1 (COMP005) (n=255): a single dose (25mg) monotherapy compared with placebo. This trial is designed to replicate the treatment response seen in our Phase 2b trial (n=233). We plan to conduct the COMP005 study mostly at sites in the U.S. We expect to report top-line data in the fourth quarter of 2024.

• Pivotal trial 2 (COMP006) (n= 568): a fixed repeat dose monotherapy using three dose arms: 25mg, 10mg and 1mg. This trial is designed to investigate whether a second dose can increase treatment responders and whether a second dose can improve responses observed in our Phase 2b trial and to explore the potential for a meaningful treatment response from repeat administration of COMP360 10mg. We expect to report top-line data by mid-2025.

• The primary endpoint in both pivotal trials is the change from baseline in MADRS total score at week 6.

Each of these trials will have a pivotal component and a long-term follow-up component. The long-term follow-up component in both trials is similar. The long-term follow up component will include a 26 week extension where patients will remain in their original assigned treatment arms and patients who meet criteria for re-treatment will have the option to receive a further treatment session according to their assigned dose. This will be followed by a 26 week open label component during which all patients who meet criteria for re-treatment will have the option to receive a 25mg dose of COMP360 psilocybin. We believe that this design will enable us to characterize better the durability of COMP360 administration.

During the first quarter of 2023, we commenced a Phase 2 (n=102) study to investigate the safety and tolerability of COMP360 psilocybin treatment in patients with major depressive disorder, or MDD. In addition, pharmacokinetics of COMP360 psilocybin treatment will be investigated. We expect to submit the results of this study as part of our submission package for approval of COMP360 psilocybin treatment in TRD.

Phase 2 Study in PTSD

We conducted a Phase 2 clinical trial to assess the safety and tolerability of COMP360 psilocybin treatment, administered with psychological support, in people with PTSD, as a result of trauma experienced as adults. It was a multicenter, fixed-dose open label study. Twenty-two participants received a single 25mg dose of investigational COMP360 psilocybin treatment. In line with the study design, participants are being monitored for a 12-week period post dosing. We plan to announce safety and efficacy data over that period in the spring of 2024.

Phase 2 Study in Anorexia

We are conducting a double-blind randomized controlled Phase 2 clinical trial investigating the safety and efficacy of COMP360 psilocybin, administered with psychological support, in people with anorexia nervosa. It is a multicenter study and will enroll 60 patients. We had experienced some delays due to challenges in recruiting and screening participants for our Phase 2 trial in anorexia nervosa. To address these challenges, we amended the trial protocol and adjusted our procedures.

Other Indications: Investigator-Initiated Studies, or IISs

With respect to clinical studies, we work with leading academic institutions and researchers under IIS clinical trial agreements. These institutions include: Imperial College London, King’s College London, Maryland Oncology Hematology, New York State Psychiatric Institute at Columbia University Medical Center, Sheppard Pratt, UC San Diego School of Medicine, University of Copenhagen, and University of Zurich. The indications previously explored or currently being explored in these IIS signal-generating and mechanistic studies include: anorexia nervosa, autism, bipolar type II depression, body dysmorphic disorder, chronic cluster headache, depression in cancer, MDD, severe TRD, and suicidal ideation.

We supply our IIS researchers with COMP360 psilocybin and encourage the open publication of all study findings. If an IIS using COMP360 psilocybin produces results with the potential to improve mental health care, we may seek to advance this research through a clinical development program, with the goal of making it available for patients, although we have no pre-existing contractual right to do so. In addition to providing our IIS researchers with COMP360 psilocybin, we have in the past offered, and may continue to offer, support with regulatory submissions. Through our IIS collaborations, we ultimately hope to bring more innovation to patients, as quickly and safely as possible.

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In May 2022, we announced that we would fund an IIS that will use COMP360 psilocybin to explore how COMP360 psilocybin affects specific brain pathways in autistic adults. The double-blind, randomized, placebo-controlled study will investigate whether there is a difference in the function of serotonin brain networks in autistic and non-autistic adults. The researchers will use a range of imaging techniques and behavioral tasks to examine how the serotonin system is modulated by COMP360 psilocybin. This exploratory study is being conducted by a research scientist who is employed by us and is a PhD student at King’s College London. The study is being conducted at the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King’s College London and is co-sponsored by King’s IoPPN and South London and Maudsley NHS Foundation Trust. It will enroll 70 adult participants, including 40 autistic people and 30 non-autistic people.

Data from IISs

In 2020, Imperial College London, London, UK completed an IIS of COMP360 titled “Psilocybin for Major Depressive Disorder: Comparative Mechanisms” (Psilodep-RCT, ClinicalTrials.gov Identifier: NCT03429075). In this randomized, double-blind, exploratory clinical trial, the efficacy and mechanisms of action of COMP360 were compared with those of a six-week course of the SSRI, escitalopram. A total of 59 adult participants with MDD of at least moderate severity were randomized to receive either two 25mg doses of COMP360 three weeks apart or six weeks of daily escitalopram (10mg for three weeks and 20mg for the following three weeks) alongside two 1mg doses COMP360 three weeks apart. In both trial arms, participants received psychological support as part of the trial. The primary efficacy endpoint of the change from baseline on the 16-item Quick Inventory of Depressive Symptomatology-Self-Report (QIDS-SR-16) showed a two-point trend in favor of the COMP360 arm which was apparent from week 1. Adjusted-response rates for QIDS-SR-16 (defined as ≥50% reduction from baseline in the QIDS-SR-16 total score) at week 6 were 70.2% for the COMP360 arm vs. 48.0% for the escitalopram arm and adjusted-remission rates (defined as a QIDS-SR-16 total score ≤5) at week 6 were 57.1% and 29.1%, respectively. For the MADRS – a more widely used and accepted clinician-rated scale which Compass is using as the primary endpoint in their clinical trials – a least square means treatment difference of -7.2 was found. Similar patterns were found on other secondary endpoints measuring work and social functioning, anxiety, avoidance, anhedonia, and wellbeing. This work has been published in the New England Journal of Medicine (Carhart-Harris et al. 2021).

In 2021, Maryland Oncology Hematology at the Aquilino Cancer Center in Rockville, Maryland, U.S. completed an IIS of COMP360 titled “The Safety and Efficacy of Psilocybin in Cancer Patients with Major Depressive Disorder” (ClinicalTrials.gov Identifier: NCT04593563). In this open-label study involving 30 patients with a cancer diagnosis and MDD, patients received a 25mg dose of COMP360 in conjunction with psychological support. Patients began with an average MADRS score of 25.9, representing moderate depression and after COMP360 psilocybin treatment, the average score decreased by 19.1 points. A sustained response (a decrease of ≥50% in the MADRS total score from baseline observed at any visit up to and including week 3, and also fulfilled at week 8) was seen in 24 patients; 15 patients showed remission of depressive symptoms (a MADRS score <10) one week after a single dose of COMP360, which was sustained up to eight weeks. COMP360 psilocybin treatment was found to be generally well-tolerated with no treatment-related serious adverse events. Adverse effects on the day of dosing were transient and as expected in line with other studies included headache, changes in sensory perception, and mood alteration. Top-line results were published in JAMA Oncology in April 2023 and the full results and methodology from this study were published in Cancer in December 2023.

In 2022, Sheppard Pratt Health System completed an IIS of COMP360 titled “An Open Label Study of the Safety and Efficacy of COMP360 in Participants With Severe Treatment-Resistant Depression (P-TRD)”. The investigator presented data from this study at the Society of Biological Psychiatry Annual Meeting in the second quarter of 2022. In this open-label study involving 12 patients with severe treatment-resistant depression, patients received a 25mg dose of COMP360 with psychological support. All participants had tried at least five antidepressant treatments without success, prior to joining the study. The researchers found that 58.3% (n=7) of the participants had maintained MADRS response criteria at 12 weeks after COMP360 psilocybin administration, and a quarter had maintained remission (n=3). There was no increase in the suicidality score based on the MADRS, and no treatment-related serious adverse events were reported throughout the study.

In 2022, the University of California San Diego School of Medicine completed an IIS of COMP360 titled “Evaluation of Psilocybin in Anorexia Nervosa: Safety and Efficacy.” (ClinicalTrials.gov Identifier: NCT04661514). The investigator presented data from this study at the Society of Biological Psychiatry Annual Meeting in the second quarter of 2022. In this open-label study involving 10 patients with anorexia nervosa, patients received a 25mg dose of COMP360 in conjunction with psychological support. The primary aim of this study was to assess the safety and tolerability of a single 25mg dose of psilocybin in participants with anorexia nervosa based on adverse events, changes in vital signs, electrocardiograms and clinical laboratory tests. Forty percent (n=4) experienced clinically meaningful reductions at the 3-month follow-up, based on

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global score on the Eating Disorder Examination (EDE). Participants demonstrated nominally statistically significant reductions in shape concerns on the EDE at the 1-month follow-up (mean change from pre-treatment=1.3; p=0.028), and nominally statistically significant reductions in eating concerns on the EDE at the 3-month follow-up (mean change from pre-treatment=1.1; p=0.047). Changes in weight concerns on the EDE were approaching nominal statistical significance at the 3-month follow-up but were not statistically significant (mean change from pre-treatment=1.2). COMP360 psilocybin treatment was well-tolerated with no treatment-related serious adverse events reported. In July 2023, the results of this study showing the potential of investigational COMP360 psilocybin treatment in anorexia nervosa were published in Nature Medicine.

In 2022, Sheppard Pratt Health System completed an IIS of COMP360 titled “The Safety and Efficacy of Psilocybin in Participants With Type 2 Bipolar Disorder (BP-II) Depression.” (ClinicalTrials.gov Identifier: NCT0443384512). The investigator presented data from this study at the Annual Meeting of the American College of Neuropsychopharmacology (ACNP) in December 2022. In this open-label study involving 14 patients with type 2 bipolar depression, patients received a 25mg dose of COMP360 with psychological support. The study found that 86% (12 out of 14) of the participants met response and remission criteria for the MADRS scale at 12 weeks after COMP360 psilocybin treatment. There was no increase in the suicidality score based on the MADRS, no manic symptoms and no unexpected adverse events or difficulties with the dosing sessions reported throughout the study. No treatment-related serious adverse events were reported. In December 2023, the results of this study demonstrating the potential of investigational COMP360 psilocybin treatment in type 2 bipolar depression were published in JAMA Psychiatry.

In 2022, University of Zurich completed an IIS of COMP360 titled “Phase II, Randomized, Double Blind, Placebo Controlled, Parallel Group, Single Center Study of Psilocybin Efficacy in Major Depression.” (ClinicalTrials.gov Identifier: NCT03715127). The investigator published data from this study in The Lancet (Von Rotz et al, Lancet 2023; 56:101809). In this double-blind, randomized clinical trial, 52 patients with major depressive disorder were randomized 1:1 to receive either a single, moderate dose (0.215 mg/kg body weight) of COMP360 psilocybin or placebo in conjunction with psychological support. MADRS and Beck's Depression Inventory (BDI) scores were assessed to estimate depression severity and the primary endpoints were defined as changes from baseline to two weeks after the administration of COMP360. At the two-week endpoint, response rates resulted in 58% for MADRS (COMP360 psilocybin: 15/26 vs. Placebo: 4/26; P = 0.0034) and for BDI in 54% (COMP360 psilocybin: 14/26 vs. Placebo: 3/26; P = 0.0025). At the two-week endpoint, remission rates were reported in 54% of patients for MADRS (COMP360 psilocybin: 14/26 vs. Placebo: 3/26; P = 0.0023) and assessed by BDI in 46% (COMP360 psilocybin: 12/26 vs. Placebo: 3/26; P = 0.013). Adverse events were in line with other studies and included headache, dizziness, nausea and diarrhea. No cases of suicidal behavior occurred during the trial period of approximately one month and no treatment-related serious adverse events were reported.

Preclinical and Drug Discovery Programs

Mechanistic Studies

We are working with academic researchers and CROs to investigate the mechanistic characteristics of psilocybin treatment. We have also established a network of PhD studentships predominantly within the United Kingdom (namely at the following universities: University of Oxford, University of Bristol, University of Reading and University of Southampton) to research elements of this work. Our mechanistic research utilizes our COMP360 and currently focuses on the following themes:

•Study of the mechanisms by which psilocin, the active moiety of our high-purity polymorphic crystalline formulation psilocybin, and other psychedelic agents engage receptors in recombinant cell-based assays (collaboration with Professor Trevor Sharp, University of Oxford). The aim here is to understand which systems are optimal to use for discovery research, and to understand further how different drugs may influence receptor-mediated signal transduction;

•Through collaborations with the University of Bristol (Professor Matt Jones, in particular) and CROs (e.g. Neurotar and Synapcell), we are also investigating the integrated electrophysiological response to psychedelic administration, to determine how changes in neuronal excitatory activity mediate brain-wide changes in resting state network activity;

•Preclinical academic collaborations with the University of Bristol, Harvard University, Oxford University and the Southern Denmark University to study the effects of our high-purity polymorphic crystalline formulation of psilocybin on a number of different aspects of behavior, including affective bias, reward learning and compulsive behavior that may provide insights relevant to information processing alterations frequently observed in mental health conditions;

•Collaborations with the University of Reading and the University of Southampton also focus on understanding what the potential role of inflammatory modulating processes might be in the mechanism of action of COMP360;

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•A study of the sustained effects of our high-purity polymorphic crystalline formulation psilocybin through the investigation of short- and long-term changes in gene expression (mRNA) and epigenetic regulation (miRNA and DNA methylation) as part of ongoing work with CROs (Sygnature and ActiveMotif)

•A healthy volunteer study with Imperial College London, investigating the acute and long-term psychological and brain effects of psilocybin treatment, using COMP360.

These studies will further our understanding of the mechanism of action and inform our decisions over which other indications to explore, beyond TRD and PTSD.

Drug Discovery Center

On August 5, 2020, we established a Drug Discovery Center under a sponsored research agreement with the University of the Sciences in Philadelphia, Pennsylvania (which merged into Saint Joseph’s University in 2022), or USciences, to focus on developing optimized psychedelic and related compounds targeting the 5-HT2A receptor, which is believed to mediate the potential therapeutic effects of psychedelics. Pursuant to the agreement, USciences is performing research services on our behalf, and has granted us an exclusive, royalty bearing, worldwide license, including rights to sublicense, all jointly held intellectual property for any and all purposes, and a non-exclusive, fully paid-up, worldwide license to any pre-existing intellectual property utilized over the course of performing the services. Under the agreement, we will pay a one-time research service fee of an estimated $0.5 million and tiered payments upon completion of certain milestones by USciences up to an aggregate of $0.9 million per licensed product covered by a valid claim of a patent included in the intellectual property rights licensed to us under the agreement, as well as a low single-digit royalty percentage on annual net sales of licensed products covered by a valid claim of a patent included in the intellectual property rights licensed to us under the agreement, subject to certain reductions. In addition, USciences is entitled to a low double-digit percentage of sublicense revenue for agreements entered into prior to a Phase 2 trial, and a mid-single-digit percentage of sublicense revenue for agreements entered into after the start of a Phase 2 trial. Unless earlier terminated, the agreement terminates upon the expiration or revocation of the last valid claim of any patent included in the joint intellectual property. We and USciences can terminate the agreement in the event of a material breach by the other party and failure to cure such breach within a certain period of time. Additionally, we and USciences can terminate the research service in the event of a material safety or regulatory issue with respect to the research service. We may also terminate the research service at will upon sixty (60) days prior written notice to USciences. USciences can terminate the research service if such services would materially and negatively interfere with its operations or upon the continuation of a force majeure event. There are no current licensed patents or patent applications under the sponsored research agreement.

Ongoing research on prodrug development has led to a number of potential candidate leads being identified that we plan to continue through further research-based development.

Investment

Delix Therapeutics

On March 6, 2020 we made a strategic investment to acquire 1,250,000 shares of series seed preferred stock in Delix Therapeutics, Inc., a drug discovery and development company researching novel small molecules for use in CNS indications. Delix Therapeutics develops non-hallucinogenic psychoplastogens, which are molecules capable of promoting neural plasticity without hallucinogenic effects, by modifying existing psychedelics. These compounds may have potential for a range of neuropsychiatric conditions.

Therapist Training

Our therapist training program was originally designed by experts from the fields of psychology, psychiatry and psychedelic therapy research. We are continuously evaluating opportunities to improve the quality and scalability of our therapist training program. To date, we have trained more than 300 therapists, approximately 150 of whom have been approved to lead sessions independently, and approximately 100 of whom are engaged in our active clinical trials. This number will increase as more sites open for our Phase 3 clinical trials in TRD as well as our other clinical trials. Therapists are often referred to us by clinical trial sites and are employed by the sites. Details of our therapist training program were published in February 2021 in the peer-reviewed journal Frontiers in Psychiatry.

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Our core training curriculum consists of:

•Tier I - Theoretical Training: Approximately five hours of self-paced online learning through our interactive therapist training platform, including a therapist manual, videos illustrating the competencies required from therapists throughout preparation, psilocybin administration, and integration sessions with study participants, and self-assessed knowledge checks;

•Tier II - Practical Clinical Skills Training: Approximately 30 hours of live, remotely-delivered (via Zoom) interactive learning, led by therapist trainers;

•Tier III - Clinical training: At this stage, therapists review a selection of session recordings from our previous clinical trials (on our interactive therapist training platform), and support one participant in a COMP360 psilocybin treatment study alongside a therapist qualified to lead sessions independently. Following completion of Tier III, therapists are able to lead sessions independently; and

•Tier IV - Continuous Professional Development: Therapists receive mentoring and support throughout their participation in our clinical studies. Mentors have access to recordings of sessions (with participant consent) led by their mentees, and are therefore able to provide adequate feedback to ensure fidelity to the psychological support model.

Our therapist training program is currently available to professionals involved in our ongoing studies. As we scale, we may expand our training to a larger pool of qualified healthcare professionals.

Using Digital Technology

We believe digital technology will change the way patients access psychotherapy services and manage their mental health conditions. We anticipate software applications will enhance activities traditionally done with an in-person therapist. We also believe remote consultations will help to remove barriers to accessing treatment such as stigma or lack of transportation. Furthermore, digital tools will enable greater self-care, as they support patients managing depressive episodes on their own and will be used to complement and augment psychotherapy and pharmacological treatments.

Working with third parties, we currently use digital technology in a number of ways:

•An online and mobile app preparation platform for participants in our TRD trial to educate them and help prepare them for their psilocybin experience;

•A web-based “shared knowledge” interactive therapist training platform, complementing our comprehensive face-to-face training program;

•Collection of measurements in our clinical trials, including remote data collection using mobile devices so patients do not need to travel into study sites for all in-clinic visits;

•Collection of some digital phenotyping information through the measurement of human-smartphone interactions; and

•Harnessing AI and natural language processing capabilities to potentially characterize the mechanism of change and assess therapist fidelity to our treatment protocol for psychological support. We are building an in-house digital team with experts in digital technology, engineering, and AI, which we refer to as augmented intelligence as well as artificial intelligence. We will continue to collaborate with other digital companies to research, develop and ultimately commercialize proprietary digital technology solutions that have the potential to complement and augment our investigational COMP360 psilocybin treatment. We believe this may enable us to offer a personalized, preventative and predictive care model.

Manufacturing and Supply

We do not own or operate, and currently have no plans to establish, any manufacturing facilities. We rely on contract drug manufacturing organizations, or CDMOs, to synthesize the active pharmaceutical ingredient, or API, that comprises COMP360, and to blend the API excipients and encapsulate. All manufacturing processes are contracted to be compliant with current Good Manufacturing Practice (cGMP). We expect to continue to rely on third parties for the production of all clinical supply drug substance and drug product that we may use. We use additional contract manufacturers to fill, label, package, store and distribute our drug product. We currently rely on a single supplier for our API but have identified additional

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manufacturers who have the appropriate experience and expertise to act as back-up suppliers of API and fill-and-finish services. We believe we maintain sufficient supply of API to avoid any material disruptions in the event of any need to replace one or more of our suppliers.

Commercialization

If our COMP360 psilocybin treatment is approved, we plan to use our own sales and marketing capabilities, targeting public and private healthcare providers and clinic networks in the U.S. In select geographies outside the U.S., we may enter into commercialization collaborations with third parties who have complementary commercial capabilities.

Upon any approval, we intend to offer a range of services to enable the safe and effective use of COMP360 with psychological support in clinical practice. These services are expected to include therapist training, information and education for patients and healthcare providers, and implementation support for treatment centers, such as guidance on procurement and installation of equipment, certification, and quality assurance.

In order to create a new mental health care model, we have established Centers of Excellence to serve as research facilities and innovation labs. In January 2021, we established our first Center of Excellence, with The Sheppard Pratt Institute for Advanced Diagnostics and Therapeutics, in Baltimore, Maryland, in the United States. In strategic collaboration with King’s College London and South London and Maudsley NHS Foundation Trust, or SLaM, we opened The Center for Mental Health Research and Innovation with an overarching goal of accelerating patient access to evidence-based innovation in mental health care by driving forward research in psychedelic therapies through, among other things, the development of working model psychedelic treatment clinics, therapist training programs, conducting clinical trials, and data analysis. The Center currently serves as a clinical trial site for our Phase 3 COMP006 trial.

Recently, we entered into research collaborations with Hackensack Meridian Health, a leading not-for-profit health care organization in New Jersey, and Greenbrook TMS, which operates through 130 company-operated treatment centers throughout the United States, to research and investigate models for the delivery of scalable, commercial COMP360 psilocybin treatment within healthcare systems, assuming FDA approval.

Competition

Our industry is characterized by many newly emerging and innovative technologies, intense competition and a strong emphasis on proprietary product rights. While we believe that our investigational COMP360 psilocybin treatment represents a fundamental shift in the treatment paradigm relative to other TRD treatments, we face potential competition from many different sources, including major pharmaceutical, biopharmaceutical, specialty pharmaceutical and biotechnology companies, academic institutions, governmental agencies and medical research organizations. Any product candidates that we successfully develop and commercialize, including our investigational COMP360 psilocybin treatment, will compete with the standard of care and new therapies, both pharmacological and somatic, that may become available in the future.

Currently, only two pharmacotherapies are approved for TRD in the U.S.: Spravato (esketamine), marketed by Janssen, which is an NMDA receptor antagonist; and olanzapine and fluoxetine hydrochloride capsules, which are available generically. Because TRD, by definition, encompasses patients who have not been helped after two or more MDD therapies, antidepressants indicated for use in MDD are frequently prescribed, combined or augmented with a second agent to treat TRD patients. Several biopharmaceutical companies have therapies in clinical development for TRD. We are aware that Supernus Pharmaceuticals and Neurocrine Biosciences, among others, are developing treatments for TRD or inadequate response to treatment in major depressive disorder.

Multiple somatic therapies are also used in TRD, such as ECT and rTMS. Psychotherapeutic approaches, like CBT, are used for MDD and TRD patients.

We also face competition from 501(c)(3) non-profit medical research organizations, including the Usona Institute. Such non-profits may be willing to provide psilocybin-based products at cost or for free, undermining our potential market for COMP360. In addition, a number of for-profit biotechnology companies or institutions are specifically pursuing the development of psilocybin to treat mental health illnesses, including TRD.

We are aware of other organizations or institutions evaluating the use of psilocybin in mental health and neurocognitive conditions. In addition, there are various companies exploring other psychedelic compounds for the treatment of mental health and neurocognitive conditions.

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Many of the pharmaceutical, biopharmaceutical and biotechnology companies with whom we may compete 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 potential competitors have significantly greater experience than we have in undertaking non-clinical 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 MHRA 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. An increasing number of companies are increasing their efforts in discovery of new psychedelic compounds.

Patents and Other Intellectual and Proprietary Rights

Obtaining, maintaining and defending global patents and other intellectual property (“IP”) rights, whether independently or in collaboration with our partners, are of key importance in the protection and commercialization of the Company’s innovative therapies and technology solutions. We shall continue to seek global patent, trademark, and trade secret protection of our innovations in the U.S., EU, UK, and other key jurisdictions. This includes pursuing patent protection for our novel high-purity polymorphic crystalline psilocybin and related manufacturing processes, pharmaceutical compositions, formulations, and methods of treatment of psychiatric and neurological indications, including TRD, MDD, PTSD, and anorexia.

Upon regulatory approval in a particular jurisdiction, we will also seek to meaningfully protect our innovations by asserting available regulatory exclusivity including regulatory data protection and market exclusivity. For example, upon approval from the U.S. FDA, we may be entitled to five years of regulatory exclusivity for New Chemical Entity, or NCE, status and upon approval from the European Medicines Agency, or EMA, we may be entitled to ten years of regulatory exclusivity.

We will defend our patents and other IP and proprietary rights as appropriate if and when we are subjected to third-party challenges (e.g., litigation, post-grant review, inter-partes review, oppositions).

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Patents and Patent Applications

Our patent portfolio related to COMP360 includes the following patents and published patent applications:

Territory	Patent Number/Application Number	Subject Matter	Expiration Date	Corresponding Ex-U.S. Patents and Patent Applications or PCT National Stage Applications
US	10,519,175	Methods of treating treatment-resistant depression	ca.2038*	Applications filed in Australia, Brazil, Canada, China, Colombia, Eurasian Patent Organization, European Patent Office, Indonesia, Israel, India, Japan, Republic of Korea, Mexico, Malaysia, New Zealand, Philippines, Saudi Arabia, Singapore, Thailand, and South Africa.
US	10,947,257	Oral dosage forms of crystalline psilocybin; Methods of treating major depressive disorder (MDD)	ca.2038*
US	10,954,259	Crystalline psilocybin; Pharmaceutical formulations; Method of treating MDD	ca.2038*
US	11,180,517	Method of treating treatment-resistant depression	ca.2038*
US	11,505,564	Method of manufacturing	ca.2038*
US	11,629,159	Crystalline psilocybin; Pharmaceutical formulations	ca. 2038*
US	17/990,979	Crystalline psilocybin; Pharmaceutical formulations	ca. 2038*
US	18/135,265	Crystalline psilocybin; Pharmaceutical formulations	ca. 2038*
GB	2571696	Method of manufacturing	ca. 2037*
GB	2572023	Crystalline psilocybin; Pharmaceutical formulations; Medical uses (including for treatment-resistant depression); Method of manufacturing	ca. 2038*
GB	2576059	Pharmaceutical formulations	ca. 2038*
GB	2588505	Method of manufacturing	ca. 2038*
GB	2588506	Crystalline psilocybin; Pharmaceutical formulations; Method of manufacture	ca. 2038*
DE	202018006384	Crystalline psilocybin; Pharmaceutical formulations	ca. 2038*
PCT	WO/2020/212951	Methods of treating anxiety disorders and other conditions	ca. 2040*	Applications filed in U.S., Australia, Canada, China, European Patent Office, Japan and Republic of Korea.
US	11,564,935	Method of treating PTSD	ca. 2040*
US	11,738,035	Method of treating anorexia	ca. 2040*
PCT	WO2020/212948	Methods of treating neurocognitive disorders and other conditions	ca. 2040*	Applications filed in U.S., Australia, Canada, China, European Patent Office, Japan and Republic of Korea.
US	17/604,610	Method of treating depression	ca. 2040*

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PCT	WO2020/212952	Methods of treating depression and other disorders	ca. 2040*	Applications filed in U.S., Australia, Canada, China, European Patent Office, Japan, Republic of Korea and Taiwan.
PCT	WO2022/207746	Pharmaceutical formulations	ca. 2042*	Applications filed in U.S., Taiwan, Argentina, Australia, Canada, China, European Patent office, Japan, and Republic of Korea.
US	18/285,109	Pharmaceutical formulations	ca. 2042*

*In general, a U.S. patent, as well as most foreign patents, will expire after 20 years from the earliest effective filing date. In the U.S., it may be possible to extend the patent term beyond the 20 years by requesting patent term extension, or PTE, of patents that claim a product requiring regulatory approval prior to sale. PTE restores to a patent owner, patent term which was effectively “lost” due to regulatory review. Similar term extensions may be available outside of the U.S. Further, in the U.S., it may also be possible to extend beyond the 20-year patent term as a result of prosecution delays caused by the U.S. Patent and Trademark Office.

U.S. Patent No 10,519,175, was granted on December 31, 2019, with claims directed to methods of treating treatment-resistant depression with oral dosage formulations of Compass’s high-purity crystalline psilocybin (including COMP360). Three Third Party Observations were previously filed during the pendency of the application, each considered by the Examiner and found to not be a barrier to patentability. A Petition for post-grant review of the patent was filed on February 21, 2020 and was dismissed on the merits on August 20, 2020.

On December 15, 2021, Freedom to Operate, Inc., filed a petition for post-grant review of U.S. Patent No. 10,947,257. The patent owner’s response was filed on March 29, 2022. On June 22, 2022, the USPTO denied institution of the post-grant review. Freedom to Operate, Inc. filed a request for rehearing on July 22, 2022, and a request for Precedential opinion panel on August 16, 2022. The USPTO Board denied the request for Precedential Opinion Panel (POP) review on February 10, 2023. On May 23, 2023, the USPTO Board denied the request for rehearing.

On December 22, 2021, Freedom to Operate, Inc., filed a petition for post-grant review of U.S. Patent No. 10,954,259. The patent owner’s response was filed on April 11, 2022. On June 22, 2022, the USPTO denied institution of the post-grant review. Freedom to Operate, Inc. filed a request for rehearing on July 22, 2022, and a request for Precedential opinion panel on August 16, 2022. The USPTO Board denied the request for Precedential Opinion Panel (POP) review on February 10, 2023. On May 23, 2023, the USPTO Board denied the request for rehearing.

UK patent, No GB2571696, was granted in May 2020 with claims directed to large scale manufacture of psilocybin, psilocybin made by said process and formulation comprising psilocybin made by said process. The Intention to Grant was sent in December 2019, and Third-Party Observations were filed in late January 2020, shortly before grant was originally scheduled. Grant of the patent was announced in the Patents Journal on May 27, 2020. This patent has an expiry date of October 8, 2037. On June 11, 2020, Kohn & Associates PLLC filed a request at the UK Intellectual Property Office to issue a post-grant opinion on the validity of the patent claims. On April 27, 2021, the agency issued a decision to refuse the request for an opinion finding that it was inappropriate in all the circumstances to issue such an opinion. No appeal to this decision was lodged within the required 28-day period.

UK patent, No GB2572023, was granted in June 2020. This patent includes claims covering our crystalline psilocybin (including the form used in COMP360), pharmaceutical formulations of crystalline psilocybin, medical uses of crystalline psilocybin (including for treatment-resistant depression), and a method of manufacturing crystalline psilocybin. The Intention to Grant was sent in December 2019, and Third-Party Observations were filed in late January 2020. A notification of grant was mailed June 23, 2020, and grant was announced in the Patents Journal on July 22, 2020. This patent has an expiry date of June 28, 2038. On August 27, 2020, Freedom to Operate, Inc. filed a request at the UK Intellectual Property Office to issue a post-grant opinion on the validity of the patent claims. On July 28, 2021 a non-binding opinion was issued by the agency finding that granted claims 1, 3 and 10-20 are not inventive. We submitted an amendment to the patent claims and on November 5, 2021 the agency provided notice that the amended specification would be published for opposition in the Patents Journal on December 1, 2021. On December 17, 2021, the agency then issued a decision to not initiate revocation proceedings against the patent.

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On November 22, 2022, Porta Sophia filed a Third-Party Observation against international patent application WO2022/207746.

Trademarks

The Company has pursued protection for its trademarks across Classes 5, 9, 10, 35, 41, 42, 44 or various combinations thereof. Our trademark portfolio includes filings for the COMPASS, COMPASS PATHWAYS, C Design, MYPATHFINDER, and CHANTERELLE marks in the United States, European Union, and United Kingdom, as detailed in the chart below.

The Company owns registrations for the COMPASS, COMPASS PATHWAYS, and C Design marks in the United States, European Union, and United Kingdom; and for the MYPATHFINDER mark in the United Kingdom. Applications are pending for the MYPATHFINDER mark in the United States and European Union; and for the CHANTERELLE mark in the United States. The Company also owns trademark registrations and pending applications in other countries.

Mark	Territory	Class(es)	Trademark Application/Registration No.	Filing/Registration Date	Status
COMPASS	US	5, 9, 10, 35, 41, 44	6648807	February 22, 2022	Registered
	EU	5, 9, 10, 35, 41, 44	1568499	May 25, 2021	Registered
	UK	5, 9, 10, 35, 41, 44	3476175	August 10, 2020	Registered
COMPASS PATHWAYS	US	5, 9, 10, 35, 41, 44	6648818	February 22, 2022	Registered
	EU	5, 9, 10, 35, 41, 44	1570415	June 1, 2021	Registered
	UK	5, 9, 10, 35, 41, 44	3476163	August 14, 2020	Registered
	US	5, 35, 41, 42, 44	6836992	September 6, 2022	Registered
	US	9, 10	90801777	June 29, 2021	Pending
	EU	5, 41, 44	1644148	June 30, 2022	Registered
	UK	5, 41, 44	1644148	May 5, 2022	Registered
MYPATHFINDER	US	9, 42	97174167	December 15, 2021	Pending
	EU	9, 42	1685580	June 7, 2022	Pending
	UK	9, 42	1685580	December 15, 2022	Registered
CHANTERELLE	US	9, 42	97626719	October 11, 2022	Pending

Government Regulation

The FDA and other regulatory authorities at federal, state and local levels, as well as in foreign countries, extensively regulate, among other things, the research, development, testing, manufacture, quality control, import, export, safety, effectiveness, labeling, packaging, storage, distribution, recordkeeping, approval, advertising, promotion, marketing, post-approval monitoring and post-approval reporting of drugs. We, along with our vendors, contract research organizations and contract manufacturers, will be required to navigate the various preclinical, clinical, manufacturing and commercial approval requirements of the governing regulatory agencies of the countries in which we wish to conduct studies or seek approval of our product candidates. The process of obtaining regulatory approvals of drugs and ensuring subsequent compliance with appropriate federal, state, local and foreign statutes and regulations requires the expenditure of substantial time and financial resources.

In the United States, the FDA regulates drug products under the Federal Food, Drug, and Cosmetic Act, or FDCA, as amended, its implementing regulations and other laws. If we fail to comply with applicable FDA or other requirements at any time with respect to product development, clinical testing, approval or any other legal requirements relating to product manufacture, processing, handling, storage, quality control, safety, marketing, advertising, promotion, packaging, labeling, export, import, distribution, or sale, we may become subject to administrative or judicial sanctions or other legal consequences. These sanctions or consequences could include, among other things, the FDA’s refusal to approve pending applications, issuance of clinical holds for ongoing studies, suspension or revocation of approved applications, warning or untitled letters, product withdrawals or recalls, product seizures, relabeling or repackaging, total or partial suspensions of manufacturing or distribution, injunctions, fines, civil penalties or criminal prosecution.

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The process required by the FDA before our product candidates are approved as drugs for therapeutic indications and may be marketed in the United States generally involves the following:

•Completion of extensive preclinical studies in accordance with applicable regulations, including studies conducted in accordance with good laboratory practice, or GLP, requirements;

•Completion of the manufacture, under current Good Manufacturing Practices, or cGMP, conditions, of the drug substance and drug product that the sponsor intends to use in human clinical trials along with required analytical and stability testing;

•Submission to the FDA of an investigational new drug application, or IND, which must become effective before clinical trials may begin;

•Approval by an institutional review board, or IRB, or independent ethics committee at each clinical trial site before each trial may be initiated;

•Performance of adequate and well-controlled clinical trials in accordance with applicable IND regulations, good clinical practice, or GCP, requirements and other clinical trial-related regulations to establish the safety and efficacy of the investigational product for each proposed indication;

•Submission to the FDA of a New Drug Application, or NDA;

•Payment of user fees for FDA review of the NDA;

•A determination by the FDA within 60 days of its receipt of an NDA, to accept the filing for review;

•Satisfactory completion of one or more FDA pre-approval inspections of the manufacturing facility or facilities where the drug will be produced to assess compliance with cGMP requirements to assure that the facilities, methods and controls are adequate to preserve the drug’s identity, strength, quality and purity;

•Potentially, satisfactory completion of FDA audit of the clinical trial sites that generated the data in support of the NDA; and

•FDA review and approval of the NDA, including consideration of the views of any FDA advisory committee, prior to any commercial marketing or sale of the drug in the United States.

Preclinical Studies and Clinical Trials for Drugs

Before testing any drug in humans, the product candidate must undergo rigorous preclinical testing. Preclinical studies include laboratory evaluations of drug chemistry, formulation and stability, as well as in vitro and animal studies to assess safety and in some cases to establish the rationale for therapeutic use. The conduct of preclinical studies is subject to federal and state regulation, including GLP requirements for safety/toxicology studies. The results of the preclinical studies, together with manufacturing information and analytical data, must be submitted to the FDA as part of an IND. An IND is a request for authorization from the FDA to administer an investigational product to humans and must become effective before clinical trials may begin. Some long-term preclinical testing may continue after the IND is submitted. The IND automatically becomes effective 30 days after receipt by the FDA, unless the FDA, within the 30-day time period, raises concerns or questions about the conduct of the clinical trial, including concerns that human research subjects will be exposed to unreasonable health risks, and imposes a full or partial clinical hold. FDA must notify the sponsor of the grounds for the hold and any identified deficiencies must be resolved before the clinical trial can begin. Submission of an IND may result in the FDA not allowing clinical trials to commence or not allowing clinical trials to commence on the terms originally specified in the IND. A clinical hold can also be imposed once a trial has already begun, thereby halting the trial until the deficiencies articulated by FDA are corrected.

The clinical stage of development involves the administration of the product candidate to healthy volunteers or patients under the supervision of qualified investigators, who generally are physicians not employed by or under the trial sponsor’s control, in accordance with GCP requirements, which include the requirements that all research subjects provide their informed consent for their participation in any clinical trial. Clinical trials are conducted under protocols detailing, among

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other things, the objectives of the clinical trial, administration procedures, subject selection and exclusion criteria and the parameters and criteria to be used in monitoring safety and evaluating effectiveness. Each protocol, and any subsequent amendments to the protocol, must be submitted to the FDA as part of the IND. Furthermore, each clinical trial must be reviewed and approved by an IRB for each institution at which the clinical trial will be conducted to ensure that the risks to individuals participating in the clinical trials are minimized and are reasonable compared to the anticipated benefits. The IRB also approves the informed consent form that must be provided to each clinical trial subject or his or her legal representative and must monitor the clinical trial until completed. The FDA, the IRB, or the sponsor may suspend or discontinue a clinical trial at any time on various grounds, including a finding that the subjects are being exposed to an unacceptable health risk. There also are requirements governing the reporting of ongoing clinical trials and completed clinical trials to public registries. Information about clinical trials, including results for clinical trials other than Phase 1 investigations, must be submitted within specific timeframes for publication on www.ClinicalTrials.gov, a clinical trials database maintained by the National Institutes of Health.

A sponsor who wishes to conduct a clinical trial outside of the United States may, but need not, obtain FDA authorization to conduct the clinical trial under an IND. If a foreign clinical trial is not conducted under an IND, FDA will nevertheless accept the results of the study in support of an NDA if the study was conducted in accordance with GCP requirements, and the FDA is able to validate the data through an onsite inspection if deemed necessary.

Clinical trials to evaluate therapeutic indications to support NDAs for marketing approval are typically conducted in three sequential phases, which may overlap.

•Phase 1—Phase 1 clinical trials involve initial introduction of the investigational product into healthy human volunteers or patients with the target disease or condition. These studies are typically designed to test the safety, dosage tolerance, absorption, metabolism and distribution of the investigational product in humans, excretion, the side effects associated with increasing doses, and, if possible, to gain early evidence of effectiveness.

•Phase 2—Phase 2 clinical trials typically involve administration of the investigational product to a limited patient population with a specified disease or condition to evaluate the drug’s potential efficacy, to determine the optimal dosages and administration schedule and to identify possible adverse side effects and safety risks.

•Phase 3—Phase 3 clinical trials typically involve administration of the investigational product to an expanded patient population to further evaluate dosage, to provide statistically significant evidence of clinical efficacy and to further test for safety, generally at multiple geographically dispersed clinical trial sites. These clinical trials are intended to establish the overall risk/benefit ratio of the investigational product and to provide an adequate basis for product approval and physician labeling.

Post-approval trials, sometimes referred to as Phase 4 clinical trials or post-marketing studies, may be conducted after initial marketing approval. These trials are used to gain additional experience from the treatment of patients in the intended therapeutic indication and are commonly intended to generate additional safety data regarding use of the product in a clinical setting. In certain instances, the FDA may mandate the performance of Phase 4 clinical trials as a condition of NDA approval.

Progress reports detailing the results of the clinical trials, among other information, must be submitted at least annually to the FDA. Written IND safety reports must be submitted to the FDA and the investigators fifteen days after the trial sponsor determines the information qualifies for reporting for serious and unexpected suspected adverse events, findings from other studies or animal or in vitro testing that suggest a significant risk for human volunteers and any clinically important increase in the rate of a serious suspected adverse reaction over that listed in the protocol or investigator brochure. The sponsor must also notify the FDA of any unexpected fatal or life-threatening suspected adverse reaction as soon as possible but in no case later than seven calendar days after the sponsor’s initial receipt of the information.

Concurrent with clinical trials, companies usually complete additional animal studies and must also develop additional information about the chemistry and physical characteristics of the product candidate and finalize a process for manufacturing the drug product in commercial quantities in accordance with cGMP requirements. The manufacturing process must be capable of consistently producing quality batches of the product candidate and manufacturers must develop, among other things, methods for testing the identity, strength, quality and purity of the final drug product. In addition, appropriate packaging must be selected and tested, and stability studies must be conducted to demonstrate that the product candidate does not undergo unacceptable deterioration over its shelf life.

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US Marketing Approval for Drugs

Assuming successful completion of the required clinical testing, the results of the preclinical studies and clinical trials, together with detailed information relating to the product’s chemistry, manufacture, controls and proposed labeling, among other things, are submitted to the FDA as part of an NDA package requesting approval to market the product for one or more indications. An NDA is a request for approval to market a new drug for one or more specified indications and must contain proof of the drug’s safety and efficacy for the requested indications. The marketing application is required to include both negative and ambiguous results of preclinical studies and clinical trials, as well as positive findings. Data may come from company-sponsored clinical trials intended to test the safety and efficacy of a product’s use or from a number of alternative sources, including studies initiated by investigators. To support marketing approval, the data submitted must be sufficient in quality and quantity to establish the safety and efficacy of the investigational product to the satisfaction of the FDA. The FDA must approve an NDA before a drug may be marketed in the United States.

The FDA reviews all submitted NDAs before it accepts them for filing and may request additional information rather than accepting the NDA for filing. The FDA must make a decision on accepting an NDA for filing within 60 days of receipt, and such decision could include a refusal to file by the FDA. Once the submission is accepted for filing, the FDA begins an in-depth substantive review of the NDA. The FDA reviews an NDA to determine, among other things, whether the drug is safe and effective for the indications sought and whether the facility in which it is manufactured, processed, packaged or held meets standards designed to assure the product’s continued safety, quality and purity. Under the goals and policies agreed to by the FDA under the Prescription Drug User Fee Act, or PDUFA, the FDA targets 10 months, from the filing date, in which to complete its initial review of a new molecular entity NDA and respond to the applicant, and six months from the filing date of a new molecular entity NDA for priority review. The FDA does not always meet its PDUFA goal dates for standard or priority NDAs, and the review process is often extended by FDA requests for additional information or clarification.

Further, under PDUFA, as amended, each NDA must be accompanied by a substantial user fee. The FDA adjusts the PDUFA user fees on an annual basis. Fee waivers or reductions are available in certain circumstances, including a waiver of the application fee for the first application filed by a small business. In addition, no user fees are assessed on NDAs for products designated as orphan drugs, unless the product also includes a non-orphan indication.

The FDA also may require submission of a Risk Evaluation and Mitigation Strategy, or REMS, if it believes that a REMS is necessary to ensure that the benefits of the drug outweigh its risks. A REMS can include use of risk evaluation and mitigation strategies like medication guides, physician communication plans, assessment plans, and/or elements to assure safe use, such as restricted distribution methods, patient registries, or other risk-minimization tools.

The FDA may refer an application for a novel drug to an advisory committee. An advisory committee is a panel of independent experts, including clinicians and other scientific experts, which reviews, evaluates and provides a recommendation as to whether the application should be approved and under what conditions. The FDA is not bound by the recommendations of an advisory committee, but it considers such recommendations carefully when making decisions.

Before approving an NDA, the FDA typically will inspect the facility or facilities where the product is manufactured. The FDA will not approve an application unless it determines that the manufacturing processes and facilities are in compliance with cGMP requirements and are adequate to assure consistent production of the product within required specifications. In addition, before approving an NDA, the FDA may inspect one or more clinical trial sites to assure compliance with GCP and other requirements and the integrity of the clinical data submitted to the FDA.

After evaluating the NDA and all related information, including the advisory committee recommendation, if any, and inspection reports regarding the manufacturing facilities and clinical trial sites, the FDA may issue an approval letter, or, in some cases, a complete response letter. A complete response letter generally contains a statement of specific conditions that must be met in order to secure final approval of the NDA and may require additional clinical or preclinical testing in order for the FDA to reconsider the application. Even with submission of this additional information, the FDA ultimately may decide that the application does not satisfy the regulatory criteria for approval. If and when those conditions have been met to the FDA’s satisfaction, the FDA will typically issue an approval letter. An approval letter authorizes commercial marketing of the drug with specific prescribing information for specific indications.

Even if the FDA approves a product, depending on the specific risks to be addressed it may limit the approved indications for use of the product, require that contraindications, warnings or precautions be included in the product labeling, require that post-approval studies, including Phase 4 clinical trials, be conducted to further assess a drug’s safety after approval, require testing and surveillance programs to monitor the product after commercialization, or impose other conditions, including

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distribution and use restrictions or other risk management mechanisms under a REMS, which can materially affect the potential market and profitability of the product. The FDA may prevent or limit further marketing of a product based on the results of post-marketing studies or surveillance programs. After approval, some types of changes to the approved product, such as adding new indications, manufacturing changes, and additional labeling claims, are subject to further testing requirements and FDA review and approval.

Expedited Development and Review Programs for Drugs

The FDA maintains several programs intended to facilitate and expedite development and review of new drugs to address unmet medical needs in the treatment of serious or life-threatening diseases or conditions. These programs include Fast Track designation, Breakthrough Therapy designation, Priority Review and Accelerated Approval, and the purpose of these programs is to either expedite the development or review of important new drugs to get them to patients more quickly than standard FDA review timelines typically permit.

A drug is eligible for Fast Track designation if it is intended to treat a serious or life-threatening disease or condition and demonstrates the potential to address unmet medical needs for such disease or condition. Fast Track designation provides increased opportunities for sponsor interactions with the FDA during preclinical and clinical development, in addition to the potential for rolling review once a marketing application is filed. Rolling review means that the agency may review portions of the marketing application before the sponsor submits the complete application. In addition, a drug may be eligible for Breakthrough Therapy designation if it is intended to treat a serious or life-threatening disease or condition and preliminary clinical evidence indicates that the drug may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints, such as substantial treatment effects observed early in clinical development. Breakthrough Therapy designation provides all the features of Fast Track designation in addition to intensive guidance on an efficient drug development program, and FDA organizational commitment to expedited development, including involvement of senior managers and experienced review staff in a cross-disciplinary review, where appropriate.

Any product submitted to the FDA for approval, including a product with Fast Track or Breakthrough Therapy designation, may also be eligible for additional FDA programs intended to expedite the review and approval process, including Priority Review designation and Accelerated Approval. A product is eligible for Priority Review designation, once an NDA or BLA is submitted, if the drug that is the subject of the marketing application has the potential to provide a significant improvement in safety or effectiveness in the treatment, diagnosis or prevention of a serious disease or condition. Under priority review, the FDA’s goal date to take action on the marketing application is six months compared to ten months for a standard review. Products are eligible for Accelerated Approval if they can be shown to have an effect on a surrogate endpoint that is reasonably likely to predict clinical benefit, or an effect on an intermediate clinical endpoint that can be measured earlier than an effect on irreversible morbidity or mortality, which is reasonably likely to predict an effect on irreversible morbidity or mortality or other clinical benefit, taking into account the severity, rarity, or prevalence of the condition and the availability or lack of alternative treatments.

Accelerated Approval is usually contingent on a sponsor’s agreement to conduct additional post-approval studies to verify and describe the product’s clinical benefit. Under the Food and Drug Omnibus Reform Act of 2022, or FDORA, the FDA is permitted to require, as appropriate, that such trials be underway prior to approval or within a specific time period after the date of approval for a product granted accelerated approval. Sponsors are also required to send updates to the FDA every 180 days on the status of such studies, including progress toward enrollment targets, and the FDA must promptly post this information publicly. Under FDORA, the FDA has increased authority for expedited procedures to withdraw approval of a drug or indication approved under accelerated approval if, for example, the sponsor fails to conduct such studies in a timely manner and send the necessary updates to the FDA, or if a confirmatory trial fails to verify the predicted clinical benefit of the product. In addition, the FDA generally requires, as a condition for Accelerated Approval, that all advertising and promotional materials intended for dissemination or publication within 120 days of marketing approval be submitted to the agency for review during the pre-approval review period. After the 120-day period has passed, all advertising and promotional materials must be submitted at least 30 days prior to the intended time of initial dissemination or publication.

Even if a product qualifies for one or more of these programs, the FDA may later decide that the product no longer meets the conditions for qualification or the time period for FDA review or approval may not be shortened. Furthermore, Fast Track designation, Breakthrough Therapy designation, Priority Review and Accelerated Approval do not change the scientific or medical standards for approval or the quality of evidence necessary to support approval, though they may expedite the development or review process.

Orphan Designation

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Under the Orphan Drug Act, the FDA may grant orphan designation to a drug intended to treat a rare disease or condition, which is generally a disease or condition that affects fewer than 200,000 individuals in the United States, or 200,000 or more individuals in the United States and for which there is no reasonable expectation that the cost of developing and making a drug available in the United States for this type of disease or condition will be recovered from sales of the product. Orphan drug designation must be requested before submitting an NDA. After the FDA grants orphan drug designation, the identity of the drug and its potential orphan use are disclosed publicly by the FDA. Orphan drug designation does not convey any advantage in or shorten the duration of the regulatory review and approval process.

Orphan drug designation entitles a party to financial incentives such as opportunities for grant funding towards clinical trial costs, tax advantages and user-fee waivers. If a drug that has orphan designation subsequently receives the first FDA approval for the disease or condition for which it has such designation, the drug is entitled to orphan drug exclusivity, which means that the FDA may not approve any other applications to market the same drug for the same indication for seven years, except in limited circumstances, such as a showing of clinical superiority to the drug with orphan exclusivity. Competitors, however, may receive approval of different drugs for the indication for which the orphan drug has exclusivity or obtain approval for the same drug but for a different indication for which the orphan drug has exclusivity. Orphan drug exclusivity also could block the approval of one of our therapeutic candidates for seven years if a competitor obtains approval of the same drug as defined by the FDA or if our therapeutic candidate is determined to be contained within the competitor’s drug for the same indication or disease. If a drug designated as an orphan drug receives marketing approval for an indication broader than what is designated, it may not be entitled to orphan drug exclusivity. Orphan drug status in the European Union has similar, but not identical, benefits.

US Post-Approval Requirements for Drugs

Drugs manufactured or distributed pursuant to FDA approvals are subject to continuing regulation by the FDA, including, among other things, requirements relating to recordkeeping, periodic reporting, product sampling and distribution, reporting of adverse experiences with the product, complying with promotion and advertising requirements, which include restrictions on promoting products for unapproved uses or patient populations (known as “off-label use”) and limitations on industry-sponsored scientific and educational activities. Although physicians may prescribe legally available products for off-label uses, manufacturers may not market or promote such uses. The FDA and other agencies 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, including investigation by federal and state authorities. Prescription drug promotional materials must be submitted to the FDA in conjunction with their first use or first publication. Further, if there are any modifications to the drug, including changes in indications, labeling or manufacturing processes or facilities, the applicant may be required to submit and obtain FDA approval of a new NDA or NDA supplement, which may require the development of additional data or preclinical studies and clinical trials.

The FDA may impose a number of post-approval requirements as a condition of approval of an NDA. For example, the FDA may require post-market testing, including Phase 4 clinical trials, and surveillance to further assess and monitor the product’s safety and effectiveness after commercialization. In addition, drug manufacturers and other entities involved in the manufacture and distribution of approved drugs, and those supplying products, ingredients, and components of them, are required to register their establishments with the FDA and certain state agencies and are subject to periodic unannounced inspections by the FDA and certain state agencies for compliance with ongoing regulatory requirements, including cGMPs, which impose certain procedural and documentation requirements. Failure to comply with statutory and regulatory requirements may subject a manufacturer to legal or regulatory action, such as warning letters, suspension of manufacturing, product seizures, injunctions, civil penalties or criminal prosecution. There is also a continuing, annual prescription drug product program user fee.

Later discovery of previously unknown problems with a product, including adverse events of unanticipated severity or frequency, or with manufacturing processes, or failure to comply with regulatory requirements, may result in revisions to the approved labeling to add new safety information, requirements for post-market studies or clinical trials to assess new safety risks, or imposition of distribution or other restrictions under a REMS. Other potential consequences include, among other things:

•Restrictions on the marketing or manufacturing of the product, complete withdrawal of the product from the market or product recalls;

•The issuance of safety alerts, Dear Healthcare Provider letters, press releases or other communications containing warnings or other safety information about the product;

•Fines, warning letters or holds on post-approval clinical trials;

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•Refusal of the FDA to approve applications or supplements to approved applications, or suspension or revocation of product approvals;

•Product seizure or detention, or refusal to permit the import or export of products;

•Injunctions or the imposition of civil or criminal penalties; and

•Consent decrees, corporate integrity agreements, debarment or exclusion from federal healthcare programs; or mandated modification of promotional materials and labeling and issuance of corrective information.

Controlled Substances

The federal Controlled Substances Act of 1970, or CSA, and its implementing regulations establish a “closed system” of regulations for controlled substances. The CSA imposes registration, security, recordkeeping and reporting, storage, manufacturing, distribution, importation and other requirements under the oversight of the DEA. The DEA is the federal agency responsible for regulating controlled substances, and requires those individuals or entities that manufacture, import, export, distribute, research, or dispense controlled substances to comply with the regulatory requirements in order to prevent the diversion of controlled substances to illicit channels of commerce.

The DEA categorizes controlled substances into one of five schedules — Schedule I, II, III, IV or V — with varying qualifications for listing in each schedule. Schedule I substances by definition have a high potential for abuse, have no currently accepted medical use in treatment in the United States and lack accepted safety for use under medical supervision. Pharmaceutical products having a currently accepted medical use that are otherwise approved for marketing may be listed as Schedule II, III, IV or V substances, with Schedule II substances presenting the highest potential for abuse and physical or psychological dependence, and Schedule V substances presenting the lowest relative potential for abuse and dependence. COMP360, if approved in the United States, will require rescheduling by the DEA before it can be marketed.

Facilities that manufacture, distribute, import or export any controlled substance must register annually with the DEA. The DEA registration is specific to the particular location, activity(ies) and controlled substance schedule(s).

The DEA inspects all manufacturing facilities to review security, recordkeeping, reporting and handling prior to issuing a controlled substance registration. The specific security requirements vary by the type of business activity and the schedule and quantity of controlled substances handled. The most stringent requirements apply to manufacturers of Schedule I and Schedule II substances. Required security measures commonly include background checks on employees and physical control of controlled substances through storage in approved vaults, safes and cages, and through use of alarm systems and surveillance cameras. Once registered, manufacturing facilities must maintain records documenting the manufacture, receipt and distribution of all controlled substances. Manufacturers must submit periodic reports to the DEA of the distribution of Schedule I and II controlled substances, Schedule III narcotic substances, and other designated substances. Registrants must also report any controlled substance thefts or significant losses, and must obtain authorization to destroy or dispose of controlled substances. Imports of Schedule I and II controlled substances for commercial purposes are generally restricted to substances not already available from a domestic supplier or where there is not adequate competition among domestic suppliers. In addition to an importer or exporter registration, importers and exporters must obtain a permit for every import or export of a Schedule I and II substance or Schedule III, IV and V narcotic, and submit import or export declarations for Schedule III, IV and V non-narcotics. In some cases, Schedule III non-narcotic substances may be subject to the import/export permit requirement, if necessary, to ensure that the United States complies with its obligations under international drug control treaties.

For drugs manufactured in the United States, the DEA establishes annually an aggregate quota for the amount of substances within Schedules I and II that may be manufactured or produced in the United States based on the DEA’s estimate of the quantity needed to meet legitimate medical, scientific, research and industrial needs. The quotas apply equally to the manufacturing of the active pharmaceutical ingredient and production of dosage forms. The DEA may adjust aggregate production quotas a few times per year, and individual manufacturing or procurement quotas from time to time during the year, although the DEA has substantial discretion in whether or not to make such adjustments for individual companies.

The states also maintain separate controlled substance laws and regulations, including licensing, recordkeeping, security, distribution, and dispensing requirements. State authorities, including boards of pharmacy, regulate use of controlled substances in each state. Failure to maintain compliance with applicable requirements, particularly as manifested in the loss or diversion of controlled substances, can result in enforcement action that could have a material adverse effect on our business,

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operations and financial condition. The DEA may seek civil penalties, refuse to renew necessary registrations, or initiate proceedings to revoke those registrations. In certain circumstances, violations could lead to criminal prosecution.

U.S. Foreign Corrupt Practices Act

The U.S. Foreign Corrupt Practices Act, to which we are subject, prohibits corporations and individuals from engaging in certain activities to obtain or retain business or to influence a person working in an official capacity. It is illegal to pay, offer to pay or authorize the payment of anything of value to any foreign government official, government staff member, political party or political candidate in an attempt to obtain or retain business or to otherwise influence a person working in an official capacity.

Regulation and Procedures Governing Approval of Medicinal Products in the European Union

In order to market any product outside of the United States, a company must also comply with numerous and varying regulatory requirements of other countries and jurisdictions regarding quality, safety and efficacy and governing, among other things, clinical trials, marketing authorization, commercial sales and distribution of products. Whether or not it obtains FDA approval for a product, an applicant will need to obtain the necessary approvals by the comparable foreign regulatory authorities before it can initiate clinical trials or marketing of the product in those countries or jurisdictions. Specifically, the process governing approval of medicinal products in the EU generally follows the same lines as in the United States, although the approval of a medicinal product in the United States is no guarantee of approval of the same product in the EU, either at all or within the same timescale as approval may be granted in the United States. It entails satisfactory completion of pharmaceutical development, non-clinical studies and adequate and well-controlled clinical trials to establish the safety and efficacy of the medicinal product for each proposed indication. It also requires the submission to relevant competent authorities for clinical trials authorization and subsequently of a marketing authorization application, or MAA, before the product can be marketed and sold in the EU or any of its Member States. If we fail to comply with applicable requirements, we may be subject to withdrawal of regulatory approvals, product recalls, seizure of products, operating restrictions and criminal prosecution.

Clinical Trial Approval

In the EU, an applicant for authorization of a clinical trial must obtain prior approval from the national competent authority of the EU Member States in which the clinical trial is to be conducted. Furthermore, the applicant may only start a clinical trial at a specific study site after the relevant independent ethics committee has issued a favorable opinion. In April 2014, the EU adopted the Clinical Trials Regulation (EU) No 536/2014, which replaced the previous Clinical Trials Directive 2001/20/EC on January 31, 2022 and overhauls the system of approvals for clinical trials in the EU. Specifically, the new legislation, which is directly applicable in all EU Member States (meaning that no national implementing legislation in each EU Member State is required), aims at simplifying and streamlining the approval of clinical trials in the EU. For instance, the Clinical Trials Regulation provides for a streamlined application procedure via a single-entry point (instead of submitting applications separately to each national competent authority and ethics committee in the Member States in which the trial will be conducted) and strictly defined deadlines for the assessment of clinical trial applications. The Clinical Trials Regulation also makes it more efficient for EU Member States to evaluate and authorize applications together, via the Clinical Trials Information System. The transitory provisions of the Clinical Trials Regulation provide that, by January 31, 2025, all ongoing clinical trials must have transitioned to the new EU Clinical Trials Regulation.

Marketing Authorization

To obtain a marketing authorization for a medicinal product in the European Economic Area (comprised of the EU Member States plus Norway, Iceland and Liechtenstein), or EEA, an applicant must submit an MAA, either under a centralized procedure administered by the EMA or one of the procedures administered by competent authorities in the EU Member States (decentralized procedure, national procedure, or mutual recognition procedure). A marketing authorization may be granted only to an applicant established in the EEA.

The centralized procedure provides for the grant of a single marketing authorization by the European Commission that is valid throughout the EEA and is mandatory for certain products, including products with a new active substance indicated for the treatment of HIV, AIDS, cancer, neurodegenerative disorders, diabetes, auto-immune and other immune dysfunctions, and viral diseases. For those products for which the use of the centralized procedure is not mandatory, pursuant to Regulation (EC) No 726/2004, applicants may elect to use the centralized procedure where either the product contains a new active substance indicated for the treatment of diseases other than those on the mandatory list, where the applicant can show that the product constitutes a significant therapeutic, scientific or technical innovation, or for which a centralized authorization would be in the interest of public health. Our investigational COMP360 psilocybin treatment, as a new active substance indicated for the treatment of treatment-resistant depression, will have the option to be filed through the centralized procedure.

Under the centralized procedure, the Committee for Medicinal Products for Human use, or the CHMP, which is the EMA’s committee that is responsible for human medicines, is responsible for conducting the assessment of whether a

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medicine meets the required quality, safety and efficacy requirements, and whether it has a positive risk/benefit profile. Under the centralized procedure, the maximum timeframe for the evaluation of an MAA is 210 days from the receipt of a valid MAA, excluding clock stops when additional information or written or oral explanation is to be provided by the applicant in response to questions asked by the CHMP. Clock stops may extend the timeframe of evaluation of an MAA considerably beyond 210 days. Where the CHMP gives a positive opinion, it provides the opinion together with supporting documentation to the European Commission, who make the final decision to grant a marketing authorization. Within 67 days from the date of the CHMP opinion, the European Commission will adopt its final decision on the MAA. Accelerated evaluation may be granted by the CHMP in exceptional cases, when a medicinal product is of major interest from the point of view of public health and, in particular, from the viewpoint of therapeutic innovation. If the CHMP accepts such a request, the timeframe of 210 days for assessment will be reduced to 150 days (excluding clock stops), but it is possible that the CHMP may revert to the standard time limit for the centralized procedure if it determines that the application is no longer appropriate to conduct an accelerated assessment.

Now that the UK (which comprises Great Britain and Northern Ireland) has left the EU, Great Britain is no longer covered by centralized marketing authorizations (under the Northern Ireland Protocol, centralized marketing authorizations currently continue to be recognized in Northern Ireland). On January 1, 2024, a new international recognition framework was put in place by the MHRA, under which the MHRA may have regard to decisions on the approval of marketing authorizations made by the EMA and certain other regulators. The MHRA also has the power to have regard to marketing authorizations approved in EU Member States through decentralized or mutual recognition procedures with a view to more quickly granting a marketing authorization in the United Kingdom or Great Britain.

The decentralized marketing authorization procedure allows an applicant to apply for simultaneous authorization in more than one EU Member State of medicinal products that have not yet been authorized in any EU Member State and that do not fall within the mandatory scope of the centralized procedure.

The mutual recognition procedure is based on the acceptance by the competent authorities of the EU Member States of the marketing authorization of a medicinal product by the competent authorities of another EU Member State. The holder of a national marketing authorization may submit an application to the competent authority of an EU Member State requesting that this authority recognize the marketing authorization delivered by the competent authority of another EU Member State.

PRIME Scheme

In March 2016, the EMA launched a scheme that is intended to reinforce early dialogue with, and regulatory support from, the EMA in order to stimulate innovation, optimize development and enable accelerated assessment of Priority Medicines, or PRIME. It is intended to build upon the scientific advice scheme and accelerated assessment procedure offered by the EMA. The scheme is voluntary and eligibility criteria must be met for a medicine to qualify for PRIME.

The PRIME scheme is open to medicines under development and for which the applicant intends to apply for an initial MAA through the centralized procedure. Eligible products must target conditions for which there is an unmet medical need (there is no satisfactory method of diagnosis, prevention or treatment in the EU or, if there is, the new medicine will bring a major therapeutic advantage) and they must demonstrate the potential to address the unmet medical need by introducing new therapy methods or improving existing ones. Applicants will typically be at the exploratory clinical trial phase of development, and will have preliminary clinical evidence in patients to demonstrate the promising activity of the medicine and its potential to address to a significant extent an unmet medical need. In exceptional cases, applicants from the academic sector or SMEs (small and medium sized enterprises) may submit an eligibility request at an earlier stage of development if compelling non-clinical data in a relevant model provide early evidence of promising activity, and first in man studies indicate adequate exposure for the desired pharmacotherapeutic effects and tolerability.

If a medicine is selected for the PRIME scheme, the EMA:

•appoints a rapporteur from the CHMP or from the Committee for Advanced Therapies (CAT) to provide continuous support and to build up knowledge of the medicine in advance of the filing of an MAA;

•issues guidance on the applicant’s overall development plan and regulatory strategy;

•organizes a kick-off meeting with the rapporteur and experts from relevant EMA committees and working groups;

•provides a dedicated EMA contact person; and

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•provides scientific advice at key development milestones, involving additional stakeholders, such as health technology assessment bodies and patients, as needed.

Medicines that are selected for the PRIME scheme are also expected to benefit from the EMA’s accelerated assessment procedure at the time of application for marketing authorization. Where, during the course of development, a medicine no longer meets the eligibility criteria, support under the PRIME scheme may be withdrawn.

Orphan Designation

Regulation (EC) No. 141/2000 and Regulation (EC) No. 847/2000 provide that a product can be designated as an orphan medicinal product by the European Commission if its sponsor can establish that: (1) the product is intended for the diagnosis, prevention or treatment of a life-threatening or chronically debilitating condition; (2) either (i) such condition affects no more than five in ten thousand persons in the EU when the application is made, or (ii) it is unlikely that the marketing of the product in the EU, without the benefits derived from orphan status, would generate sufficient return to justify the necessary investment in its development; and (3) there exists no satisfactory method of diagnosis, prevention, or treatment of such condition authorized for marketing in the EU or, if such method exists, the product would be of significant benefit compared to products available for that condition.

An orphan designation provides a number of benefits in the EU, including fee reductions, regulatory assistance and the ability to apply for a centralized marketing authorization. The application for orphan designation must be submitted before the application for marketing authorization. Orphan designation does not convey any advantage in, or shorten the duration of, the regulatory review and approval process. The grant of a marketing authorization for an orphan medicinal product leads to a ten-year period of market exclusivity. During this market exclusivity period, neither the EMA nor the European Commission or competent authorities of the Member States can accept an application or grant a marketing authorization for the same therapeutic indication in respect of a “similar medicinal product”. A “similar medicinal product” is defined as a medicinal product containing a similar active substance or substances as contained in an authorized orphan medicinal product, and which is intended for the same therapeutic indication. The market exclusivity period for the authorized therapeutic indication may, however, be reduced to six years if, at the end of the fifth year, it is established that the product no longer meets the criteria for orphan designation, for example because the product is sufficiently profitable not to justify market exclusivity. There are also limited derogations from the ten-year period of market exclusivity pursuant to which marketing authorization may be granted for a similar medicinal product in the same therapeutic indication. These are where: (i) the second applicant can establish that although their product is similar to the orphan medicinal product already authorized, the second product is safer, more effective or otherwise clinically superior; (ii) the marketing authorization holder for the authorized orphan product consents to the second orphan medicinal product application; or (iii) the marketing authorization holder for the authorized orphan product cannot supply enough orphan medicinal product.

Pediatric Development

In the EU, companies developing a new medicinal product must agree upon a pediatric investigation plan, or PIP, with the EMA’s Pediatric Committee, or PDCO, and must conduct pediatric clinical trials in accordance with that PIP unless the EMA has granted a product-specific waiver, a class waiver, or a deferral for one or more of the measures included in the PIP. This requirement also applies when a company wants to add a new indication, pharmaceutical form or route of administration for a medicine that is already authorized. The PIP sets out the timing and measures proposed to generate data to support a pediatric indication of the product for which marketing authorization is being sought. The MAA for the product must include the results of pediatric clinical trials conducted in accordance with the PIP, unless a waiver applies, or a deferral has been granted by the PDCO of the obligation to implement some or all of the measures of the PIP until there are sufficient data to demonstrate the efficacy and safety of the product in adults, in which case the pediatric clinical trials must be completed at a later date. Further, the obligation to provide pediatric clinical trial data can be waived by the PDCO when this data is not needed or appropriate because the product is likely to be ineffective or unsafe in children, the disease or condition for which the product is intended occurs only in adult populations, or when the product does not represent a significant therapeutic benefit over existing treatments for pediatric patients. Products that are granted a marketing authorization with the results of the pediatric clinical trials conducted in accordance with the PIP are eligible for a six-month extension of the protection under a supplementary protection certificate or SPC (provided an application for such extension is made at the same time as filing the SPC application for the product, or at any point up to two years before the SPC expires), even where the trial results are negative. In the case of orphan medicinal products, a two year extension of the orphan market exclusivity may be available. This pediatric reward is subject to specific conditions and is not automatically available when data in compliance with the PIP are developed and submitted.

Data and Market Exclusivity

In the EU, innovative medicinal products approved on the basis of a complete and independent data package qualify for eight years of data exclusivity upon grant of a marketing authorization and an additional two years of market exclusivity

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pursuant to Regulation (EC) No. 726/2004, as amended, and Directive 2001/83/EC, as amended. Data exclusivity prevents generic and biosimilar applicants from referencing the innovator’s preclinical and clinical trial data contained in the dossier of the reference product when applying for a marketing authorization for a period of eight years from the date on which the reference product was first authorized in the EU. During the additional two-year period of market exclusivity, a generic or biosimilar marketing authorization application can be submitted, and the innovator’s data may be referenced, but no generic or biosimilar medicinal product can be marketed until the expiration of the market exclusivity period. The overall 10-year period will be extended to a maximum of 11 years if, during the first eight years of those 10 years, the marketing authorization holder obtains an authorization for one or more new therapeutic indications which, during the scientific evaluation prior to authorization, is held to bring a significant clinical benefit in comparison with existing therapies. There is no guarantee that a product will be considered by the EMA to be an innovative medicinal product, and products may not qualify for data exclusivity. Even if a product is considered to be an innovative medicinal product so that the innovator gains the prescribed period of data exclusivity, another company may market another version of the product if such company obtained marketing authorization based on an MAA with a complete and independent data package of pharmaceutical tests, preclinical tests and clinical trials.

Periods of Authorization and Renewals

A marketing authorization is valid for five years, in principle, and it may be renewed after five years on the basis of a re-evaluation of the risk benefit balance by the EMA or by the competent authority of the authorizing EU Member State. Once renewed, the marketing authorization is valid for an unlimited period, unless the European Commission or the competent authority decides, on justified grounds relating to pharmacovigilance, to proceed with one additional five-year renewal period. Any authorization that is not followed by the placement of the product on the EEA market (in the case of the centralized procedure) or on the market of the authorizing EU Member State (for a national procedure) within three years after authorization ceases to be valid (the so-called sunset clause).

Controlled Drugs Classification

In the UK, psilocybin and psilocin are considered Class A drugs under the Misuse of Drugs Act 1971, as amended, and as Schedule 1 drugs under the Misuse of Drugs Regulations 2001, as amended. Class A drugs are considered to be the most potentially harmful, and have the highest level of control exerted over them under the Misuse of Drugs Act 1971. Similarly, Schedule 1 of the Misuse of Drugs Regulations 2001 lists those drugs to which the most restrictive controls apply: they are considered to have no legitimate or medicinal use, and can only be imported, exported, produced, supplied and the like under a license issued by the UK Government’s Home Office. If and when granted a marketing authorization by the MHRA in respect of the UK, psilocybin would still remain a Schedule 1 drug unless and until rescheduled by the UK Government’s Home Office. Unless and until psilocybin is rescheduled under the Misuse of Drugs Regulations 2001, and unless a statutory exemption was to be passed for COMP360 following the grant of a UK marketing authorization and before rescheduling, any prescribing doctors in the UK would require a Home Office license to prescribe COMP360, and similarly any patients to whom COMP360 was prescribed would require a Home Office license to possess COMP360. There can be no guarantee that such Home Office licenses would be granted or that rescheduling would be successful.

The position in the Member States of the EU is not harmonized: Member States have implemented the relevant UN Conventions (the Single Convention of Narcotic Drugs 1961 and the Convention on Psychotropic Substances 1971) into their national legislation, which has led to differences in how controlled substances are regulated in different countries of the EU. It is therefore important to determine at a national level whether a substance is controlled and to comply with the applicable legal requirements. If we are successful in obtaining a marketing authorization in key EU Member States, it is likely that rescheduling of psilocybin will also be required to enable prescribing.

Regulatory Requirements After Marketing Authorization

Following approval, the holder of the marketing authorization is required to comply with a range of requirements applicable to the manufacturing, marketing, promotion and sale of the medicinal product.

These include compliance with the EU’s stringent pharmacovigilance or safety reporting rules, pursuant to which post-authorization studies and additional monitoring obligations can be imposed. The holder of a marketing authorization must establish and maintain a pharmacovigilance system and appoint an individual qualified person for pharmacovigilance, who is responsible for oversight of that system. Key obligations include expedited reporting of suspected serious adverse reactions and submission of periodic safety update reports, or PSURs.

In addition, all new MAAs must include a risk management plan, or RMP, describing the risk management system that the company will put in place to document measures to prevent or minimize the risks associated with the product. The regulatory authorities may also impose specific obligations as a condition of the marketing authorization. Such risk-

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minimization measures or post-authorization obligations may include additional safety monitoring, more frequent submission of PSURs, or the conduct of additional clinical trials or post-authorization safety studies. RMPs and PSURs are routinely available to third parties requesting access, subject to limited redactions.

Furthermore, the manufacturing of authorized products, for which a separate manufacturer’s license is mandatory, must also be conducted in strict compliance with the applicable EU laws, regulations and guidance, including Directive 2001/83/EC, Directive (EU) 2017/1572, Regulation (EC) No 726/2004 and the European Commission Guidelines for Good Manufacturing Practice. These requirements include compliance with the EU cGMP standards which mandate the methods, facilities and controls used in manufacturing, processing and packing of products to assure their safety and identity.

Finally, the marketing and promotion of authorized products, including industry-sponsored continuing medical education and advertising directed toward the prescribers of products, are strictly regulated in the EU under Directive 2001/83/EC, as amended. The advertising of prescription-only medicines to the general public is not permitted in the EU, or in the UK under the Human Medicines Regulations 2012. Although general requirements for advertising and promotion of medicinal products are established under EU Directive 2001/83/EC as amended, the details are governed by regulations in each EU Member State and can differ from one country to another.

The aforementioned EU rules are generally applicable in the EEA (which consists of the EU Member States plus Norway, Iceland and Liechtenstein).

Reform of the Regulatory Framework in the European Union

The European Commission introduced legislative proposals in April 2023 that, if implemented, will replace the current regulatory framework in the EU for all medicines (including those for rare diseases and for children). The European Commission has provided the legislative proposals to the European Parliament and the European Council for their review and approval. In October 2023, the European Parliament published draft reports proposing amendments to the legislative proposals, which will be debated by the European Parliament. Once the European Commission’s legislative proposals are approved (with or without amendment), they will be adopted into EU law.

Brexit and the Regulatory Framework in the United Kingdom

The UK formally left the EU (commonly referred to as “Brexit”) on January 31, 2020 and the EU and the UK have concluded a trade and cooperation agreement, or TCA, which was provisionally applicable since January 1, 2021 and has been formally applicable since May 1, 2021. The TCA includes specific provisions concerning pharmaceuticals, which include the mutual recognition of GMP, inspections of manufacturing facilities for medicinal products and GMP documents issued, but does not provide for wholesale mutual recognition of UK and EU pharmaceutical regulations.

At present, Great Britain has implemented EU legislation on the marketing, promotion and sale of medicinal products through the Human Medicines Regulations 2012 (as amended) (under the Northern Ireland Protocol, the EU regulatory framework currently continues to apply in Northern Ireland). Except in respect of the EU Clinical Trials Regulation, the regulatory regime in Great Britain therefore largely aligns with EU regulations, however it is possible that these regimes will diverge more significantly in future now that Great Britain’s regulatory system is independent from the EU and the TCA does not provide for mutual recognition of UK and EU pharmaceutical legislation. However, notwithstanding that there is no wholesale recognition of EU pharmaceutical legislation under the TCA, under a new international recognition procedure mentioned above which was put in place by the MHRA on January 1, 2024, the MHRA may take into account decisions on the approval of a marketing authorization from the EMA (and certain other regulators) when considering an application for a Great Britain marketing authorization.

On February 27, 2023, the UK government and the European Commission announced a political agreement in principle to replace the Northern Ireland Protocol with a new set of arrangements, known as the “Windsor Framework”. This new framework fundamentally changes the existing system under the Northern Ireland Protocol, including with respect to the regulation of medicinal products in the UK. In particular, the MHRA will be responsible for approving all medicinal products destined for the UK market (i.e., Great Britain and Northern Ireland), and the EMA will no longer have any role in approving medicinal products destined for Northern Ireland. A single UK-wide marketing authorization will be granted by the MHRA for all medicinal products to be sold in the UK, enabling products to be sold in a single pack and under a single authorization throughout the UK. The Windsor Framework was approved by the EU-UK Joint Committee on March 24, 2023, so the UK government and the EU will enact legislative measures to bring it into law. On June 9, 2023, the MHRA announced that the medicines aspects of the Windsor Framework will apply from January 1, 2025.

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Coverage, Pricing and Reimbursement

Significant uncertainty exists as to the coverage and reimbursement status of any product candidates for which we obtain regulatory approval. In the United States and markets in other countries, sales of any psilocybin treatment for which we receive regulatory approval for commercial sale will depend, in part, on the availability of coverage and reimbursement for our products from third-party payors, such as government health care programs (e.g., Medicare, Medicaid), managed care providers, private health insurers, health maintenance organizations, and other organizations. These third-party payors decide which medications they will pay for and will establish reimbursement levels. The availability of coverage and extent of reimbursement by governmental and other third-party payors is essential for most patients to be able to afford treatments such as novel therapies. In the United States, the principal decisions about reimbursement for new medicines are typically made by the Centers for Medicare & Medicaid Services, or CMS, which is a part of 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:

•a covered benefit under its health plan;

•safe, effective and medically necessary;

•appropriate for the specific patient;

•cost-effective; and

•neither experimental nor investigational.

Our ability to successfully commercialize our product candidates, whether as a single agent or combination therapy, 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. Even if coverage is provided, the approved reimbursement amount may not be high enough to allow us to establish or maintain price levels sufficient to realize an appropriate return on our investment in product development.

No uniform policy for coverage and reimbursement for products exist among third-party payors in the United States. 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 medical product or service does not ensure that other payors will also provide coverage for the medical product or service, or will provide coverage at an adequate reimbursement rate. 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.

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 and have a material adverse effect on our sales, results of operations and financial condition. If 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, if we or our collaborators develop therapies for use with our product candidates, we, or our collaborators, will be required to obtain coverage and reimbursement for these therapies separate and apart from the coverage and reimbursement we seek for our product candidates, once approved.

Further, third-party payors are increasingly challenging the price and examining the medical necessity and cost-effectiveness of medical products and services, in addition to their safety and efficacy. In order to secure coverage and reimbursement for any product candidate 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 such product, in addition to the costs required to obtain FDA or comparable 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

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level of payment may not be sufficient to allow a company to sell its products at a profit. A decision by a third-party payor not to cover a product could reduce physician utilization once the product is approved and have a material adverse effect on sales, our operations and financial condition. We expect to experience pricing pressures from third-party payors in connection with the potential sale of any of our product candidates.

Lastly, in some foreign countries, the proposed pricing for a drug must be approved before it may be lawfully marketed. The requirements governing drug pricing vary widely from country to country. For example, in the EU, pricing and reimbursement schemes vary widely from country to country. Some EU Member States provide that products may be marketed only after a reimbursement price has been agreed. Some EU Member States may require the completion of additional studies that compare the cost effectiveness of a particular product candidate to currently available therapies (so called health technology assessments) in order to obtain reimbursement or pricing approval. For example, EU Member States have the option to restrict the range of products for which their national health insurance systems provide reimbursement and to control the prices of medicinal products for human use. EU Member States may approve a specific price for a product or may instead adopt a system of direct or indirect controls on the profitability of the company placing the product on the market. Approaches between EU 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 pharmaceutical products will allow favorable reimbursement and pricing arrangements for any of our product candidates. Other EU Member States allow companies to fix their own prices for products, but monitor and control prescription volumes and issue guidance to physicians to limit prescriptions. Recently, many countries in the EU have increased the level of discounts required on pharmaceuticals and these efforts could continue as countries attempt to manage health care expenditures, especially in light of the severe fiscal and debt crises experienced by many countries in the EU. The downward pressure on health care costs in general, particularly prescription products, has become intense. As a result, increasingly high barriers are being erected to the entry of new products. Political, economic and regulatory developments may further complicate pricing negotiations, and pricing negotiations may continue after reimbursement has been obtained. Reference pricing used by various EU Member States and parallel trade (arbitrage between low-priced and high-priced EU Member States) can further reduce prices. Acceptance of any medicinal product for reimbursement may come with cost, use and often volume restrictions, which again can vary by country. In addition, results-based rules of reimbursement may apply. There can be no assurance that any country that has price controls or reimbursement limitations for pharmaceutical products will allow favorable reimbursement and pricing arrangements for any of our products, if approved in those countries. Historically, products launched in the EU do not follow price structures of the United States and generally prices tend to be significantly lower.

Notwithstanding any of the above, as Schedule I substances under the Controlled Substances Act, psilocybin and psilocin are currently deemed to have no accepted medical use and therapies that use psilocybin or psilocin are currently precluded from reimbursement in the United States.

Other Healthcare Laws and Compliance Requirements

Healthcare providers, physicians, and third-party payors will play a primary role in the recommendation and prescription of any products for which we obtain marketing approval. Our business operations and any current or future arrangements with third-party payors, healthcare providers and physicians may expose us to broadly applicable federal and state fraud and abuse laws, as well as other healthcare laws and regulations. These laws may impact, among other things, our business or financial arrangements and relationships through which we research, as well as market, sell and distribute the psilocybin therapies for which we obtain approval. In addition, we may be subject to health information privacy regulation by both the federal government and the states in which we conduct our business. In the United States the laws that may affect our ability to operate include, among others:

•The federal Anti-Kickback Statute, which prohibits, among other things, persons and entities from knowingly and willfully soliciting, receiving, offering or paying any remuneration (including any kickback, bribe, or rebate), directly or indirectly, overtly or covertly, in cash or in kind, to induce, or in return for, either the referral of an individual, or the purchase, lease, order, arrangement or recommendation of any good, facility, item or service for which payment may be made, in whole or in part, under a federal healthcare program, such as Medicare and Medicaid. The term remuneration has been interpreted broadly to include anything of value. Further, courts have found that if “one purpose” of remuneration is to induce referrals, the federal Anti-Kickback Statute is violated. The federal Anti-Kickback Statute has been interpreted to apply to arrangements between manufacturers on one hand and prescribers, purchasers, and formulary managers on the other. A person or entity does not need to have actual knowledge of the

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federal Anti-Kickback Statute or specific intent to violate it to have committed a violation. Violations are subject to significant administrative, civil and criminal fines and penalties for each violation, plus up to three times the remuneration involved, imprisonment, and exclusion from government healthcare programs. In addition, the government may assert that a claim including items or services resulting from a violation of the federal Anti-Kickback Statute constitutes a false or fraudulent claim for purposes of the federal False Claims Act, or FCA, or federal civil money penalties statute. There are a number of statutory exceptions and regulatory safe harbors protecting some common activities from prosecution; but the exceptions and safe harbors are drawn narrowly and require strict compliance in order to offer protection;

•The federal civil and criminal false claims laws, such as the FCA, which prohibit, among other things, individuals or entities from knowingly presenting, or causing to be presented claims for payment or approval from Medicare, Medicaid, or other third-party payors, that are false, fictitious, or fraudulent; from knowingly making, using or causing to be made or used, a false statement or record material to a false or fraudulent claim or obligation to pay or transmit property to the federal government; or from knowingly concealing or knowingly and improperly avoiding or decreasing an obligation to pay money to the federal government. Manufacturers can be held liable under the FCA even when they do not submit claims directly to government payors if they are deemed to “cause” the submission of false or fraudulent claims. The FCA also permits a private individual acting as a “whistleblower” to bring qui tam actions on behalf of the federal government alleging violations of the FCA and to share in any monetary recovery. When an entity is determined to have violated the FCA, the government may impose civil fines and penalties for each false claim, plus treble damages, and exclude the entity from participation in Medicare, Medicaid and other federal healthcare programs;

•The federal civil monetary penalties laws, which impose civil fines for, among other things, the offering or transferring of remuneration, which includes, without limitation, any transfer of items or services for free or for less than fair market value (with limited exceptions), to a Medicare or Medicaid beneficiary that the person knows or should know is likely to influence the beneficiary’s selection of a particular provider, practitioner, or supplier of items or services reimbursable by a federal or state healthcare program;

•The federal Health Insurance Portability and Accountability Act of 1996, or HIPAA, which created additional federal criminal liability for knowingly and willfully executing, or attempting to execute, a scheme to defraud any healthcare benefit program or obtain, by means of false or fraudulent pretenses, representations, or promises, any of the money or property owned by, or under the custody or control of, any healthcare benefit program, regardless of the payor (i.e., public or private) and knowingly and willfully falsifying, concealing or covering up by any trick or device a material fact or making any materially false, fictitious, or fraudulent statements or representations in connection with the delivery of, or payment for, healthcare benefits, items or services relating to healthcare matters. Similar to the federal Anti-Kickback Statute, a person or entity does not need to have actual knowledge of the statute or specific intent to violate it in order to have committed a violation;

•HIPAA, as amended by the Health Information Technology for Economic and Clinical Health Act of 2009, or HITECH, and its respective implementing regulations, which imposes, among other things, certain requirements on certain covered healthcare providers, health plans, and healthcare clearinghouses as well as their respective business associates and their covered subcontractors relating to the privacy, security and transmission of individually identifiable health information. Among other things, HITECH makes HIPAA’s privacy and security standards directly applicable to business associates, those independent contractors or agents of covered entities that create, receive, maintain, transmit or obtain protected health information in connection with providing a service on behalf of a covered entity. HITECH also increased the civil and criminal penalties that may be imposed against covered entities, business associates and possibly other persons, and gave state attorneys general new authority to file civil actions for damages or injunctions in federal courts to enforce the federal HIPAA laws and seek attorney’s fees and costs associated with pursuing federal civil actions;

•The federal Physician Payment Sunshine Act, created under the Patient Protection and Affordable Care Act, as amended by the Health Care and Education Reconciliation Act, collectively, the Affordable Care Act, or ACA, which requires applicable manufacturers of drugs, devices, biologics and medical supplies for which payment is available under Medicare, Medicaid or the Children’s Health Insurance Program to report annually to CMS, information related to payments or other transfers of value made to physicians (defined to include doctors, dentists, optometrists, podiatrists and chiropractors), certain other licensed health care practitioners, and teaching hospitals, as well as ownership and investment interests held by the physicians described above and their immediate family members;

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•Federal government price reporting laws, which require us to calculate and report complex pricing metrics in an accurate and timely manner to government programs, where such reported prices may be used in the calculation of reimbursement and/or discounts on approved products;

•Federal consumer protection and unfair competition laws, which broadly regulate marketplace activities and activities that potentially harm consumers; and

•Analogous state and foreign equivalents of each of the healthcare laws and regulations described above, such as anti-kickback and false claims laws, which may apply to items or services reimbursed by any third-party payor, including commercial insurers or patients; state and local marketing and/or transparency laws applicable to manufacturers that may be broader in scope than the federal requirements; state laws that require pharmaceutical companies to comply with the pharmaceutical industry voluntary compliance guidelines and other relevant compliance guidance promulgated by the federal government, such as the April 2003 Office of Inspector General Compliance Program Guidance for Pharmaceutical Manufacturers and/or the Pharmaceutical Research and Manufacturers of America’s Code on Interactions with Healthcare Professionals; state laws that require the reporting of information related to drug pricing; state laws that require drug manufacturers to report information related to payments and other transfers of value to physicians and other healthcare providers or marketing expenditures and pricing information; state and local laws that require the licensure and/or registration of pharmaceutical sales representatives; and state and foreign laws governing the privacy and security of health information that may be more stringent than those in the United States (such as the EU, which adopted GDPR), many of which differ from each other in significant ways and often are not preempted by HIPAA, thus complicating compliance efforts.

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

The full scope and enforcement of each of these laws is uncertain and subject to rapid change in the current environment of healthcare reform. Federal and state enforcement bodies have continued to increase their scrutiny on interactions between healthcare companies and healthcare providers, which has led to a number of significant investigations, prosecutions, convictions and settlements in the healthcare industry. It is possible that governmental authorities will conclude that our business practices do not comply with current or future statutes, regulations or case law involving applicable fraud and abuse or other healthcare laws and regulations. If our operations, including our arrangements with physicians and other healthcare providers and entities, such as our Centers of Excellence or therapists, are found to be in violation of any of such laws or any other governmental regulations that apply to us, we may be subject to significant penalties, including, without limitation, administrative, civil and criminal penalties, damages, fines, disgorgement, contractual damages, reputational harm, diminished profits and future earnings, the curtailment or restructuring of our operations, exclusion from participation in federal and state healthcare programs (such as Medicare and Medicaid), imprisonment, and additional oversight and reporting obligations if we become subject to a corporate integrity agreement or similar settlement to resolve allegations of non-compliance with these laws and the curtailment or restructuring of our operations, any of which could adversely affect our ability to operate our business and our financial results. If any of the physicians or other healthcare providers or entities with whom we expect to do business, including our Centers of Excellence and therapists, are found to be not in compliance with applicable laws, they may be subject to similar actions, penalties and sanctions.

Ensuring that our current and future business arrangements with third parties, and our business generally, comply with applicable healthcare laws and regulations, as well as responding to possible investigations by government authorities, can be time- and resource- consuming and can divert a company’s attention from its business.

Healthcare Reform

In the United States and in some foreign jurisdictions, there have been, and likely will continue to be, a number of legislative and regulatory changes and proposed 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 2010, the ACA was enacted, which, among other things, increased rebates for drugs sold to Medicaid programs owed by most manufacturers under the Medicaid Drug Rebate Program and extends the rebate program to individuals enrolled in Medicaid managed organizations; imposes mandatory discounts for certain Medicare Part D beneficiaries in which manufacturers must agree to offer 70% point-of-sale discounts off negotiated prices of applicable brand drugs to eligible beneficiaries during their coverage gap period as a condition for manufacturers’ outpatient drugs coverage under Medicare Part D; subjects drug manufacturers of certain branded prescription drugs to new annual, nondeductible fees and taxes;

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expanded healthcare fraud and abuse laws (including the FCA and the Anti-Kickback Statute), government investigative powers and enhances penalties for non-compliance; expands eligibility criteria for Medicaid programs thereby potentially increasing manufacturers’ Medicaid rebate liability; expands the entities eligible for discounts under the 340B Drug Pricing Program; created new requirements to report financial arrangements with physicians, as defined by such law, and teaching hospitals, commonly referred to as the Physician Payments Sunshine Act; created a new requirement to annually report the identity and quantity of drug samples that manufacturers and authorized distributors of record provide to physicians; created a Patient Centered Outcomes Research Institute to oversee, identify priorities in and conduct comparative clinical effectiveness research, along with funding for such research; and established the Center for Medicare and Medicaid Innovation at CMS to test innovative payment and service delivery models to lower Medicare and Medicaid spending.

Other legislative changes have been proposed and adopted in the United States since the ACA was enacted. For example, the Budget Control Act of 2011, among other things, created measures for spending reductions by Congress. This includes aggregate reductions of Medicare payments to providers of up to 2% per fiscal year. Subsequent legislation extended the 2% payment reduction which remains in effect through 2031.

The American Taxpayer Relief Act reduced Medicare payments to several types of providers, including hospitals, imaging centers and cancer treatment centers, and increased the statute of limitations period for the government to recover overpayments to providers from three to five years.

Further, on May 30, 2018, the Right to Try Act was signed into law. The law, among other things, provides a federal framework for certain patients to access certain investigational new drug products that have completed a Phase I clinical trial and that are undergoing investigation for FDA approval. Under certain circumstances, eligible patients can seek treatment without enrolling in clinical trials and without obtaining FDA permission under the FDA expanded access program. There is no obligation for a drug manufacturer to make its drug products available to eligible patients as a result of the Right to Try Act.

On March 11, 2021, President Biden signed the American Rescue Plan Act of 2021 into law, which eliminates the statutory Medicaid drug rebate cap, currently set at 100% of a drug’s average manufacturer price, for single source and innovator multiple source drugs, beginning January 1, 2024. Due to the Statutory Pay-As-You-Go Act of 2010, estimated budget deficit increases resulting from the American Rescue Plan Act of 2021, and subsequent legislation, Medicare payments to providers will be further reduced starting in 2025 absent further legislation.  These laws and regulations may result in additional reductions in Medicare and other healthcare funding and otherwise affect the prices we may obtain for any of our product candidates for which we may obtain regulatory approval or the frequency with which any such product candidate is prescribed or used.

The Inflation Reduction Act of 2022, or IRA, includes several provisions that may impact our business to varying degrees, including provisions that reduce the out-of-pocket cap for Medicare Part D beneficiaries to $2,000 starting in 2025; imposes new manufacturer financial liability on certain drugs under Medicare Part D, allow the U.S. government to negotiate Medicare Part B and Part D price caps for certain high-cost drugs and biologics without generic or biosimilar competition, require companies to pay rebates to Medicare for certain drug prices that increase faster than inflation, and delay the rebate rule that would limit the fees that pharmacy benefit managers can charge. Further, under the IRA, orphan drugs are exempted from the Medicare drug price negotiation program, but only if they have one orphan designation and for which the only approved indication is for that disease or condition. If a product receives multiple orphan designations or has multiple approved indications, it may not qualify for the orphan drug exemption. The implementation of the IRA is currently subject to ongoing litigation challenging the constitutionality of the IRA’s Medicare drug price negotiation program.The overall impact that the IRA will have on our business and the healthcare industry in general is not yet known.

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 marketed 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, review the relationship between pricing and manufacturer patient programs, reduce the cost of drugs under Medicare, and reform government program reimbursement methodologies for pharmaceutical products.

In addition, President Biden has issued multiple executive orders that have sought to reduce prescription drug costs. In February 2023, HHS also issued a proposal in response to an October 2022 executive order from President Biden that includes a proposed prescription drug pricing model that will test whether targeted Medicare payment adjustments will sufficiently incentivize manufacturers to complete confirmatory trials for drugs approved through FDA’s accelerated approval pathway. Although a number of these and other proposed measures may require authorization through additional legislation to become

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effective, and the Biden administration may reverse or otherwise change these measures, both the Biden administration and Congress have indicated that they will continue to seek new legislative measures to control drug costs. Although a number of these and other proposed measures may require authorization through additional legislation to become effective, and the Biden administration may reverse or otherwise change these measures, both the Biden administration and Congress have indicated that they will continue to seek new legislative measures to control drug costs.

At the state level, legislatures have increasingly passed legislation and implemented regulations designed to control pharmaceutical 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.

We expect that additional foreign, federal and state healthcare reform measures will be adopted in the future, any of which could limit the amounts that federal and state governments will pay for healthcare products and services, which could result in limited coverage and reimbursement and reduced demand for our products, once approved, or additional pricing pressures. It is also possible that additional governmental action will be taken in response to the COVID-19 pandemic.

Human Capital Management

As a biotechnology company dedicated to accelerating patient access to evidence-based innovation in mental health. Our team is the key to our success, and we believe it is essential to invest in building an engaged, diverse, supported, and incentivized workforce who can help us achieve our vision of a world of mental wellbeing. As of December 31, 2023, we had 186 employees, of whom 141 employees are engaged in research and development activities and 45 employees are engaged in general administrative functions. We had 181 employees as of December 31, 2022 and grew by 2.8% as of December 31, 2023. As of December 31, 2023, 32% of our employees are located in the US, while the remaining 68% are located in the UK.

We have no collective bargaining agreements with our employees and we have not experienced any work stoppages. We believe our relations with our employees are good.

Mental Health and Wellbeing

As a biotechnology company focused on mental health, we aspire to be a leader in building a workplace that reduces the stigma of mental illness and fosters employee wellbeing. We take a holistic view of wellbeing support that includes mental and physical health support for all employees at Compass.

We offer various wellbeing resources which include:

•company-paid employee health care coverage, including access and financial support for a private mental health care in the UK;

•a global employee assistance program run by certified counsellors, offering up to 18 therapy sessions per issue for team members and their families;

•one-to-one confidential wellbeing check-ins, onboarding and offboarding with our wellbeing community lead;

•community circles, providing a forum for employees to discuss any topic with colleagues, providing open communication and support;

•group health coaching series to help keep individuals on track towards their health goals;

•team meetings periodically include wellbeing segments facilitated by our wellbeing community lead and we use wellbeing team surveys and manager-led discussions during team meetings to identify and overcome any wellbeing issues;

•training for managers on how to address wellbeing issues in their teams and provide support;

•access to a meditation app with weekly group meditation sessions;

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• weekly qualified employee-led yoga sessions; and

•company-wide shutdown over the year-end holiday, to make it easier for team members to disconnect during their time off.

In 2023 we signed the StigmaFree pledge organized by the National Alliance on Mental Illness (NAMI), as part of our commitment to a company culture of openness, acceptance, and understanding about employees’ overall mental health and well-being. NAMI is the largest grassroots mental health organization in the United States dedicated to building better lives for the millions of Americans affected by mental illness.

Engagement, Culture and Values

We aim to attract and retain people who are driven by our mission to help and empower those who are suffering with mental health challenges. We strive to live our values of compassion, boldness, inclusiveness, and rigor.

In 2022 and 2023, we applied to be certified as a Most Loved Workplace by Best Practice Institute (BPI) and its Most Loved Workplaces® operation, which is a company that assesses and certifies a company as a workplace employees love based on internal surveys, external public ratings and interviews with corporate officials, ranking number 67 in the UK. The list recognizes companies that put respect, caring, and appreciation for their employees at the center of their business model.

We continue to build a positive working culture by:

•Holding periodic engagement surveys with employees and carrying out action plans to address areas for improvements. Our 2023 pulse survey demonstrated that we continue to maintain a very strong 52% net promoter score; according to Qualtrics XM Institute, a score of between 10 to 30% is good and a score of 30% or more is excellent;

•Holding focus groups with volunteers from across our company to hear their views about what we are doing well as a company and what we could do better to improve engagement;

•Holding periodic company-wide team meetings aimed to connect and receive updates from our CEO and the wider teams, with the opportunity for anonymous question and answer session with management;

•Providing additional opportunities to stay connected in our hybrid working model, for learning and social occasions;

•Holding periodic open ‘office hours’ with our chief executive officer and other members of the executive team; and

•Gathering input from new hires and employees who are leaving our company to understand what we can do better to improve our culture and engagement.

Diversity, Equity, and Inclusion

We are united in our resolve to build a safe, diverse, accepting, and inclusive culture in our workplace and have been actively involved in similar efforts in our communities. In 2023, we formed our Diversity Council, a cross-functional diverse group of employees empowered to embed diversity, equity and inclusion across our business. Focus areas of the Diversity Council include diversity in clinical trials, therapist diversity, digital accessibility, patient engagement, education and awareness and inclusive culture, recruitment, and retention.

The council advanced a number of diversity, equity and inclusion initiatives in 2023, including:

•Hosted awareness events, such as Black History Month, Hispanic Heritage Month and Pride Month;

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•Refreshed our global diversity, equity and inclusion policy. The policy covers topics like our practices and policies on recruiting talent, compensation, developing, and training employees. This policy seeks to support a diverse workforce and ensure that our team members are treated equitably;

•Supported research through a grant to the Grady Trauma Project focused on exploring the healthcare needs and attitudes towards investigational psychedelic treatments in marginalized and underprivileged communities. The results were published in the Journal of Mood & Anxiety Disorders, and “Perceptions of Psychedelic-Assisted Therapy Among Black Americans” is the first published study exploring Black Americans’ perceptions of psychedelic treatment;

•Collaborated with Phase 3 TRD clinical trial sites to support diversity in recruitment of clinical trial participants to evaluate COMP360 across ethnicities, races, and genders and identified best practices and challenges to increasing representation in clinical trials;

•Engaged patients through the Mental Health Experiences community, a private online group of people with personal experience of TRD. The community is made up of people from a range of backgrounds, including 42% ethnic minorities and 30% LBGTQ+. The community discusses different themes, such as the experience of living with depression and barriers to participating in clinical trials. Listening to people’s lived experiences and using targeted questions helps us understand the unmet needs of patients from various backgrounds and to focus on these needs as we work to develop new treatments; and

•Applied a diversity, equity and inclusion perspective to our brand refresh, ensuring our brand is accessible to those with visual impairments.

As of December 31, 2023, our board had 40% female representation and 46% of our wider senior management team was female. Overall, our total female representation in the company as of December 31, 2023, was 64%, which is well above the 49% average according to the 2022 report by Biotechnology Innovation Organization.

Employee Development and Training

We believe that the individual growth of our employees will fuel the company’s growth over time since our talent is uniquely experienced in our pioneering work. We are committed to the continued development of our employees, and to support their growth. To help us identify, foster, and retain high performing employees, we have a range of resources and initiatives, including:

•Job architecture, providing employees with guidance and clear pathways for developing and progressing their career and twice-yearly promotions cycle;

•A process for performance and development goals that is tied to employees receiving feedback throughout the year and assessing individual performance and rewards at the end of the year;

•Dedicated internal resources, including regular webinars to support employees’ personal development and career goals and embed development goals with support of mentoring and other development tools;

•Talent reviews, a twice-yearly process to assess and calibrate talent for the purposes of rewards and development;

•A learning curriculum of courses on offer delivered by external experts to develop specific skill areas;

•An annual learning and development allowance for each employee to spend on personal development/job related training;

•In-person quarterly half-day sessions to bring together our early career talent to network, learn, and socialize; and

•1:1 coaching support to facilitate the re-integration of women returning from maternity leave.

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Compensation and Benefits

We provide competitive compensation and comprehensive benefits for our employees. Our compensation packages include base salary, annual bonus, annual equity awards, company paid healthcare plans, generous paid time-off and leave policies, travel insurance, life/disability and income protection insurance, and retirement saving plans with company matching contributions. We also have an employee share purchase plan, under which eligible employees have the opportunity to buy our shares through payroll deductions every six months at a discount.

Aligned with our values, in 2023, we launched a new policy for family and dependent care and refreshed Maternity (UK), Paternity (UK), Parental Leave (US), and Adoption Leave (UK), which provide support to our multi-generational diverse workforce to care for their families. We also facilitate a parent and carers group who support each other and recommend policy changes like these to management.

Our compensation and benefits are designed to provide employees with total compensation packages that are competitive with those offered by our peers and other companies with which we compete for talent. We evaluate our offerings on an annual basis to ensure competitiveness of our programs and adjust as needed.

Ways of Working

Keeping our values in mind, we recognize that to be inclusive and compassionate, we should empower everyone to work in the ways that suit them best. Although many companies have reverted to mandatory office attendance, we have retained a hybrid working model since it is aligned with our values and it is an attractive feature of our employment value proposition. Our guidelines for ways of working set out core principles around what we expect from each other, rather than enforcing a rigid model. We look for the proof of that in our achievements, not in our working hours or location of work. We encourage employees to remain connected through virtual, casual and voluntary weekly meetups. Alongside our ways of working policy, we also have a work-from-home budget for employees to purchase items that will make working at home a more comfortable and ergonomic experience. We still recognize the importance of connecting face-to-face with colleagues for collaboration and social time in our communal spaces in London, New York, and San Francisco.

 Corporate Information

Compass Pathways plc was originally incorporated as a private limited company under the laws of England and Wales in June 2020 under the name Compass Rx Limited to become a holding company for Compass Pathfinder Holdings Limited. Compass Rx Limited was subsequently re-registered as a public limited company in August 2020 and renamed Compass Pathways plc. Compass Pathfinder Holdings Limited was originally incorporated under the laws of England and Wales in June 2017. Our registered office is located at 3rd Floor, 1 Ashley Road, Altrincham, Cheshire, WA14 2DT, United Kingdom, and our telephone number is +1 (646) 905-3974.

Our website address is www.compasspathways.com. We do not incorporate the information on or accessible through our website into this Annual Report, and you should not consider any information on, or that can be accessed through, our website as part of this Annual Report. We make available free of charge through our website our Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K and amendments to these reports filed or furnished pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended, as soon as reasonably practicable after we electronically file or furnish such materials to the U.S. Securities and Exchange Commission.

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ITEM 1A. RISK FACTORS

You should carefully consider the following risk factors as well as the other information included in this Annual Report on Form 10-K, including “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and our consolidated financial statements and related notes thereto. Any of the following risks could materially and adversely affect our business, financial condition, or results of operations. The selected risks described below, however, are not the only risks facing us. Additional risks and uncertainties not currently known to us or those we currently view to be immaterial may also materially and adversely affect our business, financial condition, or results of operations. The summary of the material risks associated with our business is included in the “Special Note Regarding Forward-Looking Statements” on page 4 above.

Risks Related to Our Financial Position and Need for Additional Capital

We are a clinical-stage biotechnology company and have incurred significant losses since our inception. We expect to incur losses for the foreseeable future and may never achieve or maintain profitability.

We are a clinical-stage biotechnology company and we have not generated any revenue to date. We have incurred significant operating losses since our formation. We incurred total net losses of $118.5 million and $91.5 million for the years ended December 31, 2023 and 2022, respectively. As of December 31, 2023, we had an accumulated deficit of $379.6 million. Our historical losses resulted principally from costs incurred in connection with research and development activities and general and administrative costs associated with our operations. In the future, we intend to continue to conduct research and development, preclinical testing, clinical trials, regulatory compliance, market access and commercialization activities that, together with anticipated general and administrative expenses, will result in incurring further significant losses for at least the next several years. Our expected losses, among other things, may continue to cause our working capital and shareholders’ equity to decrease. We anticipate that our expenses will increase substantially if and as we, among other things:

•conduct our Phase 3 program for our investigational COMP360 psilocybin treatment in TRD and continue the clinical development of our investigational COMP360 psilocybin treatment in other indications;

•continue the training of therapists to deliver our investigational COMP360 psilocybin treatment in our Phase 3 program and clinical trials;

•service our outstanding indebtedness;

•continue to invest in funding investigator-initiated studies, or IISs, including the IIS co-sponsored by King’s Institute of Psychiatry, Psychology & Neuroscience (IoPPN) and South London and Maudsley NHS Foundation Trust that will use COMP360 psilocybin treatment to explore how psilocybin affects specific brain pathways in autistic adults;

•establish a sales, marketing and distribution infrastructure and scale-up manufacturing capabilities to commercialize any therapeutic candidates for which we may obtain regulatory approval, including COMP360;

•establish and expand the network of public healthcare institutions and private clinics that administer our investigational COMP360 psilocybin treatment in conjunction with psychological support as part of our clinical trials;

•advance our commercialization strategy in the United States and Europe, including using digital technologies to enhance our proposed therapeutic offering;

•research additional indications for our investigational COMP360 psilocybin treatment and discover and develop any future therapeutic candidates;

•continue to invest in the development of prodrug candidates and psychedelic compounds that could be developed into investigational treatments;

•continue to invest in our Discovery Center and Centers of Excellence;

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•seek regulatory approvals for any future therapeutic candidates that successfully complete clinical trials;

•experience heightened regulatory scrutiny;

•pursue necessary scheduling-related decisions by the U.S. Drug Enforcement Administration, or the DEA, to enable us to commercialize any future therapeutic candidates containing controlled substances for which we may obtain regulatory approval, including COMP360;

•obtain, maintain, expand and protect our intellectual property portfolio, including litigation costs associated with defending against alleged patent or other intellectual property infringement claims;

•add clinical, scientific, operational, financial and management information systems and personnel, including personnel to support our therapeutic development and potential future commercialization efforts;

•experience any delays or encounter any issues with respect to any of the above, including failed studies, ambiguous trial results, safety issues or other regulatory challenges, including, for example, delays and other impacts as a result of a resurgence or emergence of new COVID-19 variants;

•expand our operations in the United States and Europe in the future; and

•incur additional legal, accounting and other expenses associated with operating as an English-domiciled public company listed in the United States.

To date we have funded our operations through private placements of equity, warrants and convertible notes and, since our initial public offering, or IPO, in 2020, through public equity offerings and debt financing. To become and remain profitable, we will need to continue developing and eventually commercialize treatments that generate significant revenue. This will require us to be successful in a range of challenging activities, including completing our Phase 3 clinical program of COMP360 in TRD and other clinical trials of COMP360 or any future therapeutic candidates, training a sufficient number of qualified therapists to deliver our investigational COMP360 psilocybin treatment, using digital technologies and solutions to enhance our therapeutic offering, discovering and developing any future therapeutic candidates, obtaining regulatory approval for COMP360 psilocybin treatment and any future therapeutic candidates that successfully complete clinical trials, and establishing marketing capabilities. Even if COMP360 psilocybin treatment or any of the future therapeutic candidates that we may develop are approved for commercial sale, we anticipate incurring significant costs associated with commercializing COMP360 or any other approved future therapeutic candidate. We may never succeed in these activities and, even if we do, may never generate revenue that is significant enough to achieve profitability.

Because of the numerous risks and uncertainties associated with therapeutic development, we are unable to accurately predict the timing or amount of increased expenses or when, or if, we will be able to achieve profitability. If we are required by the FDA, the EMA, the MHRA, or other comparable foreign authorities to perform studies in addition to those we currently anticipate, or if there are any delays in completing our clinical trials or the development of our investigational COMP360 psilocybin treatment or any future therapeutic candidates, our expenses could increase beyond our current expectations and revenue could be further delayed.

Even if we or any future collaborators do generate sales, we may never achieve, sustain or increase profitability on a quarterly or annual basis. Our failure to sustain profitability would depress the market price of our ADSs and could impair our ability to raise capital, repay our outstanding indebtedness, expand our business, diversify our therapeutic offerings or continue our operations. If we continue to suffer losses, investors may not receive any return on their investment and may lose their entire investment.

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We will need substantial additional funding to complete the development and commercialization of our investigational COMP360 psilocybin treatment or any future therapeutic candidates. Failure to obtain this necessary capital when needed may force us to delay, limit or terminate certain or all of our product discovery, therapeutic development, research operations or commercialization efforts or grant rights to develop and market products or therapeutic candidates that we would otherwise prefer to develop and market ourselves.

We expect to require substantial additional funding in the future to sufficiently finance our operations and to complete the development and commercialization of our investigational COMP360 psilocybin treatment or any future therapeutic candidates. If the PIPE Warrants are exercised in full for cash, we would receive an additional $159.6 million in gross proceeds. However, because the holders of the PIPE Warrants are not obligated to exercise such warrants, we have not included any anticipated proceeds from such exercises of PIPE Warrants in our estimate of our cash runway. However, in February 2024, we received an exercise notice and payment of exercise price from a holder of certain PIPE Warrants that indicates the holder intends to exercise its PIPE Warrants for ADSs and such exercise, if completed, would generate additional proceeds. We expect that our cash and cash equivalents of $220.2 million as of December 31, 2023, together with the net proceeds raised to date during the first quarter, will enable us to fund our operating expenses and capital expenditure requirements until late 2025. We have based this estimate on assumptions that may prove to be wrong, and we could use our capital resources sooner than we currently expect. Further, changing circumstances, some of which may be beyond our control, such as fluctuating inflation and interest rates, could cause us to consume capital significantly faster than we currently anticipate, and we may need to seek additional funds sooner than planned. Our future funding requirements, both short-term and long-term, will depend on many factors, including:

•the progress, timing and completion of our Phase 3 clinical program for our current investigational COMP360 psilocybin treatment program for TRD, our clinical trials in other indications, and our preclinical activities and clinical trials for future indications or any future therapeutic candidates;

•the outcome, timing and cost of seeking and obtaining regulatory approvals from the FDA, the EMA, the MHRA and comparable foreign regulatory authorities, including the potential for such authorities to require that we perform more preclinical studies or clinical trials than those that we currently expect or change their requirements on studies that had previously been agreed to;

•the outcome and timing of any scheduling-related decisions by the DEA, individual states, and comparable foreign authorities;

•the number of potential future therapeutic candidates we identify and decide to develop, either internally through our research and development efforts or externally through acquisitions, licensing or other collaboration agreements;

•the costs involved in growing our organization to the size needed to prepare for the potential commercialization of our investigational COMP360 psilocybin treatment and any future therapeutic candidates, including increasing personnel costs;

•the costs of developing sales and marketing capabilities to target public and private healthcare providers and clinic networks in major markets;

•the costs of training and certifying therapists to administer our investigational COMP360 psilocybin treatment in our Phase 3 program and other clinical trials;

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•the costs of establishing research collaborations, such as our research collaboration with Greenbrook TMS, and our Centers of Excellence and the Center for Mental Health Research, which includes conducting clinical trials, including proof of concept studies, to refine our treatment delivery model;

•the time and costs involved in generating and collecting data and advancing and defending our intellectual property portfolio, including the costs involved in filing patent applications and maintaining and enforcing patents or defending against claims of infringements or invalidity raised by third parties;

•the costs of developing, testing and deploying digital technology solutions to improve the patient experience and therapeutic process;

•the time and costs involved in obtaining regulatory approval for COMP360 or any future therapeutic candidates, and any delays we may encounter as a result of evolving regulatory requirements or adverse results with respect to COMP360 or any future therapeutic candidates;

•selling and marketing activities undertaken in connection with the potential commercialization of our investigational COMP360 psilocybin treatment or any future therapeutic candidates, if approved, and costs involved in the creation of an effective sales and marketing organization;

•the amount of revenue, if any, we may derive either directly or in the form of royalty, milestone or other payments from future sales of our investigational COMP360 psilocybin treatment and any future therapeutic candidates, if approved;

•the impact of macroeconomic events, including, among others, heightened and fluctuating inflation and interest rates, fluctuations in foreign exchange rates, and the risk of economic slowdown or recession in the United States; and

•the costs of operating as a public company.

Until we can generate sufficient revenue to finance our cash requirements, which we may never do, we expect to finance our future cash needs through a combination of public or private equity offerings, debt financings, strategic collaborations and alliances, licensing arrangements or monetization transactions.

Our ability to raise additional funds when needed and on acceptable terms or at all will depend on financial, economic and market conditions and other factors, over which we may have no or limited control. For example, the continued challenging capital markets environment, lower prices for many securities, heightened and fluctuating inflation and interest rates and concerns about potential recessionary factors may affect our ability to raise additional funding through the exercise for cash of the PIPE Warrants, sales of our securities or issuance of indebtedness, which may harm our liquidity, force us to delay, limit or terminate certain or all of our product discovery, therapeutic development, research operations or commercialization planning efforts or cause us to grant rights to develop and market products or therapeutic candidates that we would otherwise prefer to develop and market ourselves. If adequate funds are not available on commercially acceptable terms when needed, we may be forced to delay, reduce or terminate the development or commercialization of all or part of our research programs or our investigational COMP360 psilocybin treatment or any future therapeutic candidate, or we may be unable to take advantage of future business opportunities. Market volatility, geopolitical tensions resulting from the ongoing war between Ukraine and Russia, the Israel-Hamas war, heightened and fluctuating inflation and interest rates, instability in the banking system, and the related impact on U.S. and global economies, the potential for a government shutdown in the United States, the upcoming

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presidential election in the U.S., the risk of economic slowdown or recession in the United States or other factors could also adversely impact our ability to access capital as and when needed or increase our costs in order to raise capital.

We cannot guarantee that future financing will be available in sufficient amounts, or on commercially reasonable terms, or at all. Current capital market conditions, including the impact of inflation, have increased borrowing rates and can be expected to significantly increase our cost of capital as compared to prior periods. Moreover, the terms of any financing may adversely affect the holdings or the rights of holders of our ADSs, the issuance of additional securities, whether equity or debt, by us, or the possibility of such issuance, may cause the market price of our ADSs to decline. Our Loan Agreement with Hercules includes, and any future debt financing, if available, may involve agreements that include affirmative and negative restrictive covenants, such as limitations on our ability to incur additional debt, limitations on our ability to acquire, sell or license intellectual property rights and other operating restrictions that could adversely impact our ability to conduct our business. For example, our Loan Agreement with Hercules contains financial covenants requiring us to maintain a minimum cash balance of $22.5 million and we will need to raise additional financing or significantly reduce our operating expenses to maintain compliance with this financial covenant. We could also be required to seek funds through arrangements with collaborators or others at an earlier stage than otherwise would be desirable and we may be required to relinquish rights to COMP360 or any future therapeutics candidates or otherwise agree to terms unfavorable to us, any of which may have a material adverse effect on our business, operating results and prospects. Further, any additional fundraising efforts may divert our management from its day-to-day activities, which may adversely affect our ability to develop and commercialize our investigational COMP360 psilocybin treatment or any future therapeutic candidates.

In addition, heightened regulatory scrutiny could have a negative impact on our ability to raise capital. Our business activities rely on developing laws and regulations in multiple jurisdictions. It is impossible to determine the extent of the impact of any new laws, regulations or initiatives that may be proposed, or whether any proposals will become law. The regulatory uncertainty surrounding our investigational COMP360 psilocybin treatment or any future therapeutic candidates may adversely affect our business and operations, including without limitation, our ability to raise additional capital.

The PIPE Warrants may not be exercised.

The holders of the PIPE Warrant are not obligated to exercise the PIPE Warrants, so we may not receive any additional proceeds from the PIPE. The PIPE Warrants are exercisable for a three year period ending in February 2027 and have an exercise price of $9.93. In February 2024 we received an exercise notice and payment of exercise price from a holder of certain PIPE Warrants that indicates the holder intends to exercise their PIPE Warrants for ADSs. The exercise of the warrants has not settled and the underlying ADSs have not yet been issued. We believe the likelihood that these holders will exercise the PIPE Warrants, and therefore any cash proceeds that we may receive in relation to the exercise of such PIPE Warrants, will be dependent on the trading price of our ADSs relative to the exercise price. In addition, the PIPE Warrants may be exercised on a cashless basis if there is no effective registration statement registering the shares underlying the PIPE Warrants, in which case we would not receive any additional proceeds. If the PIPE Warrants are not exercised for cash, or only a portion of the PIPE Warrants are exercised for cash, we would need to obtain additional funding from other sources and may need to raise funds earlier than expected. Further, changing circumstances, some of which may be beyond our control, such as fluctuating inflation and interest rates, could cause us to consume capital significantly faster than we currently anticipate, and we may need to seek additional funds sooner than planned. Adequate additional financing may not be available to us on acceptable terms or at all.

Our limited history as a clinical stage company may make it difficult for you to evaluate the success of our business to date and to assess our future viability.

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We were formed in 2016 and to date, we have invested most of our resources in developing our investigational COMP360 psilocybin treatment, building our intellectual property portfolio, conducting business planning, raising capital and providing administrative support for these operations. Although we are conducting our first Phase 3 clinical program for our COMP360 psilocybin treatment for TRD, we have not yet demonstrated an ability to successfully complete such later-stage clinical trials, obtain regulatory approvals, manufacture a commercial-scale product, conduct sales and marketing activities necessary for successful product commercialization or obtain reimbursement in the countries of sale.

We may encounter unforeseen expenses, difficulties, complications, delays and other known or unknown factors in achieving our business objectives. If we receive regulatory approval for our COMP360 psilocybin treatment or any future product candidate, we will need to transition from a company with a clinical development focus to a company capable of supporting commercial activities. We may not be successful in such a transition.

We expect our financial condition and operating results to continue to fluctuate significantly from quarter to quarter and year to year due to a variety of factors, many of which are beyond our control. Accordingly, you should not rely upon the results of any quarterly or annual periods as indications of future operating performance.

Raising additional capital may cause dilution to holders of our ordinary shares or ADSs, restrict our operations or require us to relinquish rights to COMP360 or any future therapeutic candidates.

We may seek additional capital through a combination of equity offerings, debt financings, strategic collaborations and alliances, licensing arrangements or monetization transactions. To the extent that we raise additional capital through the sale of equity, convertible debt securities or other equity-based derivative securities or the exercise of the PIPE Warrants, your ownership interest will be diluted and the terms may include liquidation or other preferences that adversely affect your rights as a shareholder. For example, if all of the PIPE Warrants were exercised, we would issue 16,076,750 ADSs which would result in dilution to our shareholders. In addition, we have raised additional funds in the past and may raise additional funds in the future by issuing equity securities under our ATM Facility and, as a result, our stockholders have in the past and may in the future experience dilution. Our Loan Agreement with Hercules includes, and any future debt financing, if available, may involve agreements that include affirmative and negative restrictive covenants, such as limitations on our ability to incur additional debt, limitations on our ability to acquire, sell or license intellectual property rights and other operating restrictions that could adversely impact our ability to conduct our business. For example, our Loan Agreement with Hercules contains financial covenants requiring us to maintain a minimum cash balance of $22.5 million and we will need to raise additional financing or significantly reduce our operating expenses to maintain compliance with this financial covenant. Furthermore, the issuance of additional securities, whether equity or debt, by us, or the possibility of such issuance, may cause the market price of our ADSs to decline and existing shareholders may not agree with our financing plans or the terms of such financings. If we raise additional funds through strategic collaborations and alliances, licensing arrangements or monetization transactions with third parties, we may have to relinquish valuable rights to our investigational COMP360 psilocybin treatment or any future therapeutic candidates or otherwise agree to terms unfavorable to us, any of which may have a material adverse effect on our business, operating results and prospects. Adequate additional financing may not be available to us on acceptable terms, or at all. If we are unable to raise additional funds 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 our investigational COMP360 psilocybin treatment or any future therapeutic candidates that we would otherwise prefer to develop and market ourselves. Further, any additional fundraising efforts may divert our management from its day-to-day activities, which may adversely affect our ability to develop and commercialize our investigational COMP360 psilocybin treatment or any future therapeutic candidates.

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Furthermore, certain shareholders and holders of ADSs, including those in the United States, may, even in the case where preferential subscription rights have not been cancelled or limited, not be entitled to exercise such rights, unless the offering is registered or the ordinary shares are qualified for sale under the relevant regulatory framework. As a result, there is the risk that investors may suffer dilution of their holdings should they not be permitted to participate in preference right equity or other offerings that we may conduct in the future.

We may not satisfy the milestones or conditions set forth in our Loan Agreement with Hercules in order to draw down additional funding on our term loan facility.

The second tranche of term loans under our Loan Agreement with Hercules, in an amount up to $10.0 million, may only be drawn, subject to the achievement of specified performance milestones related to satisfaction of the protocol specified primary endpoint from our Phase 3 COMP005 clinical trial and the satisfaction of customary conditions. The second tranche is only available through the earlier of: (a) 30 days following achievement of certain performance milestones and (b) December 15, 2024. The third tranche of term loans under our Loan Agreement, in an amount up to $10.0 million, is available solely at the lender’s discretion and is only available during the interest-only period. If these milestones and conditions are met, each of the remaining tranches may be borrowed in up to two drawings of a minimum of $5.0 million each. Without the achievement of the required clinical milestones and satisfaction of certain customary conditions, we will not be eligible to draw additional funds under the second tranche. If we do not receive approval from Hercules’ investment committee, which is beyond our control, we will not be eligible to draw funds under the final remaining tranche under our Loan Agreement and will not realize the full benefits of our Loan Agreement. If we are unable to draw down additional funding under the terms of the Loan Agreement, our business, financial condition and results of operation may be harmed and we may be required to seek out alternative financing sources which may have less favorable terms.

Our operating activities may be restricted as a result of covenants related to our Loan Agreement, which could have a material adverse effect on our business, financial condition and results of operation.

On June 30, 2023, we entered into a Loan Agreement with Hercules for an aggregate principal amount of up to $50.0 million, of which the first tranche of $30.0 million was funded at closing. Until we have repaid such indebtedness, the Loan Agreement subjects us to various customary covenants, including requirements as to financial reporting and insurance, and restrictions on our ability to dispose of our business or property, to change our line of business, to liquidate or dissolve, to merge or consolidate with any other entity or to acquire all or substantially all the capital stock or property of another entity, to incur additional indebtedness, to incur liens on our property, to pay any dividends or other distributions on capital stock other than dividends payable solely in capital stock, to redeem capital stock, to enter into licensing agreements, to engage in transactions with affiliates, or to encumber our intellectual property. These covenants may adversely affect our ability to raise funds or enter into license agreements or strategic transactions in the future. For example, if we were to seek additional sources of debt financing in the future and indebtedness under the Loan Agreement is outstanding, we would be required to seek the consent of Hercules in order to raise such additional funds. Additionally, there is a financial covenant requiring us to maintain at least $22.5 million of cash in accounts subject to a control agreement in favor of Hercules during the period commencing on July 1, 2024 (which date is subject to adjustment if certain performance milestones are met) and at all times thereafter, provided that if we have achieved certain performance milestones, the minimum cash covenant shall not apply on any day that our market capitalization is at least $750.0 million measured on a consecutive 15-calendar day period immediately prior to such date of measurement and tested on a daily basis. We need to raise additional financing or significantly reduce our operating expenses to maintain compliance with this financial covenant. Our business may be adversely affected by these restrictions on our ability to operate our business, financial condition and results of operations.

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We may not have cash available in an amount sufficient to enable us to make interest or principal payments on our indebtedness when due and our payment obligations may be accelerated upon an event of default.

Our ability to make scheduled payments on or to refinance our indebtedness depends on our future performance and ability to raise additional sources of cash, which is subject to economic, financial, competitive and other factors beyond our control. If we are unable to generate sufficient cash to service our debt, we may be required to adopt one or more alternatives, such as selling assets, restructuring our debt or obtaining additional equity capital on terms that may be onerous or highly dilutive. If we desire to refinance our indebtedness, our ability to do so will depend on the state of the capital and lending markets and our financial condition at such time. We may not be able to engage in any of these activities or engage in these activities on desirable terms, which could result in a default on our debt obligations.

Failure to satisfy our current and future debt obligations under our Loan Agreement could result in an event of default. Additionally, we may be required to repay the outstanding indebtedness under our Loan Agreement if an event of default occurs under the Loan Agreement. Under the Loan Agreement, an event of default will occur if, among other things: we fail to make payments under the Loan Agreement; we breach any of our covenants under the Loan Agreement, subject to specified cure periods with respect to certain breaches; the lender determines that a material adverse effect has occurred; we or our assets become subject to certain legal proceedings, such as bankruptcy proceedings; or we are unable to pay our debts as they become due. As a result of the occurrence of an event of default, Hercules could accelerate all of the amounts due. In the event of an acceleration of amounts due under our Loan Agreement, we may not have enough available cash or be able to raise additional funds through equity or debt financings to repay such indebtedness at the time any such event of default occurs. In this case, we may be required to delay, limit, reduce or terminate our product development or future commercialization efforts or grant rights to develop and market our investigational COMP360 psilocybin treatment or any future therapeutic candidates that we would otherwise prefer to develop and market ourselves. Our business, financial condition and results of operations could be materially adversely affected as a result of any of these events. In addition, the Loan Agreement includes customary affirmative and negative covenants and other defaults or events of default, the occurrence and continuance of which provide Hercules with the right to demand immediate repayment of all principal and unpaid interest under the Loan Agreement, and to exercise remedies against us and the collateral securing the Loan Agreement. These defaults or events of default include, among other things, insolvency, liquidation, bankruptcy or similar events; failure to observe any covenant or secured obligation under the Loan Agreement, which failure, in most cases, is not cured within 10 days; occurrence of an event that could reasonably be expected to have a material adverse effect on our business, operations, properties, assets or financial condition; material misrepresentations; and certain money judgments being entered against us or any portion of our assets are attached or seized.

In the event of default, Hercules could accelerate all of the amounts due under the Loan Agreement. Under such circumstances, we may not have enough available cash or be able to raise additional funds through equity or debt financings to repay such indebtedness at the time of such acceleration. In that case, we may be required to delay, limit, reduce or terminate our product development or future commercialization efforts or grant rights to develop and market our investigational COMP360 psilocybin treatment or any future therapeutic candidates that we would otherwise prefer to develop and market ourselves. Hercules could also exercise their rights to take possession and dispose of the collateral securing the Loan Agreement, which includes substantially all of our property. Our business, financial condition and results of operations could be materially adversely affected as a result of any of these events.

Risks Related to Development, Clinical Testing and Commercialization of Our Investigational COMP360 Psilocybin Treatment and Any Future Therapeutic Candidates

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We are dependent on the successful development of our investigational COMP360 psilocybin treatment. We cannot give any assurance that COMP360 will successfully complete clinical trials or receive regulatory approval, which is necessary before it can be commercialized.

We currently have no treatments that are approved for commercial sale and may never be able to develop marketable treatments. We expect that a substantial portion of our efforts and expenditures over the next several years will be devoted to our investigational COMP360 psilocybin treatment, which is currently our only therapeutic candidate in clinical development. Accordingly, our business currently depends on the successful regulatory approval of COMP360 and the commercialization of our investigational COMP360 psilocybin treatment. We cannot be certain that COMP360 will receive regulatory approval or that our COMP360 psilocybin treatment will be successfully commercialized even if we receive regulatory approval. If we were required to discontinue development of our investigational COMP360 psilocybin treatment, or if COMP360 does not receive regulatory approval or fails to achieve significant market acceptance, we would be delayed by many years in our ability to achieve profitability, if ever.

The research, testing, manufacturing, safety, efficacy, labeling, approval, sale, marketing and distribution of psilocybin is, and will remain, subject to comprehensive regulation by the FDA, the DEA, the EMA, the MHRA and comparable foreign regulatory authorities. Failure to obtain regulatory approval in the United States, Europe or other jurisdictions will prevent us from commercializing and marketing our investigational COMP360 psilocybin treatment in such jurisdictions.

Even if we were to successfully obtain approval from the FDA, the EMA, the MHRA and foreign regulatory authorities for COMP360, any approval might contain significant limitations related to use, as well as restrictions for specified age groups, warnings, precautions or contraindications, such as a black box warning for increased risk of suicidal thoughts and behaviors. Furthermore, even if we obtain regulatory approval for COMP360, we will still need to develop a commercial infrastructure or develop relationships with collaborators to commercialize including securing availability of third-party treatment sites for the appropriate administration of our investigational COMP360 psilocybin treatment, secure adequate manufacturing, train and secure access to qualified therapists, establish a commercially viable pricing structure and obtain coverage and adequate reimbursement from third-party payors, including government healthcare programs. If we, or any future collaborators, are unable to successfully commercialize our investigational COMP360 psilocybin treatment, we may not be able to generate sufficient revenue to continue our business.

The success of our investigational COMP360 psilocybin treatment and any future therapeutic candidates will depend on several factors, including the following:

•successful completion of clinical trials, including our Phase 3 program in TRD and Phase 2 programs in PTSD, and anorexia nervosa and preclinical studies;

•sufficiency of our financial and other resources to complete the necessary preclinical studies and clinical trials;

•receiving regulatory approvals or clearance for conducting our planned clinical trials or future clinical trials;

•successful patient enrollment in and completion of clinical trials;

•positive data from our clinical trials that support an acceptable risk-benefit profile of COMP360 and any future therapeutic candidates in the intended populations;

•receipt and maintenance of regulatory and marketing approvals from applicable regulatory authorities;

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•establishing and scaling up, either alone or with third-party manufacturers, manufacturing capabilities of clinical supply for our clinical trials and commercial manufacturing, if COMP360 or any future therapeutic candidates are approved;

•recruiting and training therapists to administer our investigational COMP360 psilocybin treatment in our Phase 3 program and other clinical trials;

•entry into collaborations to further the development of our investigational COMP360 psilocybin treatment and any future therapeutic candidates;

•obtaining and maintaining and defending patent and trade secret protection and/or regulatory exclusivity for COMP360 and any future therapeutic candidates;

•successfully launching commercial sales of our investigational COMP360 psilocybin treatment and any future therapeutic candidates, if approved;

•acceptance of COMP360 and any future therapeutic candidates’ benefits and uses, if approved, by patients, the medical community and third-party payors;

•maintaining a continued acceptable safety profile of COMP360 and any future therapeutic candidates;

•effectively competing, including with respect to cost, with companies developing and commercializing other treatments in the indications which our investigational COMP360 psilocybin treatment targets;

•obtaining and maintaining healthcare coverage and adequate reimbursement from third-party payors;

•maintaining the strength of our reputation; and

•complying with laws and regulations, including laws applicable to controlled substances, data privacy, and pre-commercial activities.

If we are not successful with respect to one or more of these factors in a timely manner or at all, we could experience significant delays or an inability to successfully commercialize our investigational COMP360 psilocybin treatment or any future therapeutic candidates we develop, which would materially harm our business. If we do not receive marketing approvals for COMP360 and any future therapeutic candidates, we may not be able to continue our operations.

COMP360 psilocybin treatment is, and any future therapeutic candidates we may develop in the future may be, subject to controlled substance laws and regulations in the territories where the product will be marketed, such as the United States, the UK and the rest of Europe, and failure to comply with these laws and regulations, or the cost of compliance with these laws and regulations, may adversely affect the results of our business operations, both during clinical development and post approval, and our financial condition. In addition, during the review process of COMP360 psilocybin treatment, and prior to approval, the FDA and/or other regulatory bodies may require additional data, including with respect to whether COMP360 has abuse or misuse potential. This may delay approval and any potential rescheduling process.

In the United States, psilocybin and its active metabolite, psilocin, are listed by the DEA as “Controlled Substances” or scheduled substances, under the Comprehensive Drug Abuse Prevention and Control Act of 1970, also known as the Controlled Substances Act, or CSA, specifically as a Schedule I substance. The DEA regulates chemical compounds as

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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 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 criteria for importation. 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 state laws in the United States classify psilocybin and psilocin as Schedule I controlled substances. For any product containing psilocybin to be available for commercial marketing in the United States, psilocybin and psilocin must be rescheduled, or the product itself must be scheduled, by the DEA to Schedule II, III, IV or V. Commercial marketing in the United States will also require 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 psilocybin and psilocin are Schedule I controlled substances, products approved by the FDA for medical use in the United States that contain psilocybin or psilocin should be placed in Schedules II-V, since approval by the FDA satisfies the “accepted medical use” requirement. If or when COMP360 receives FDA approval, we anticipate that the DEA will make a scheduling determination and place it 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 non-clinical or clinical studies, including with respect to whether, or to what extent, the substance has abuse or misuse potential. 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 DEA to conduct notice and comment rule making including issuing an interim final rule. Such action will be subject to public comment and requests for hearing which could affect the scheduling of these substances. There can be no assurance that the DEA will make a favorable scheduling decision. Even assuming categorization as a Schedule II or lower controlled substance (i.e., Schedule III, IV or V), at the federal level, such substances would also require scheduling determinations under state laws and regulations.

If approved by the FDA, and if the finished dosage form of COMP360 is listed by the DEA as a Schedule II, III, or IV controlled substance, its manufacture, importation, exportation, domestic distribution, storage, sale and legitimate use 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 investigational COMP360 psilocybin treatment in the United States. Furthermore, the FDA, DEA, or any 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 our investigational COMP360 psilocybin treatment and any future therapeutic candidates containing controlled substances. In addition, therapeutic candidates containing controlled substances are subject to DEA regulations relating to manufacturing, storage, distribution and physician prescription procedures, including:

•DEA registration and inspection of facilities. Facilities conducting research, manufacturing, distributing, importing or exporting, or dispensing controlled substances must be registered (licensed) to perform these activities and have the security, control, recordkeeping, reporting and inventory mechanisms required by the DEA to prevent drug loss and diversion. All these facilities must renew their registrations annually, except dispensing facilities, which must

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renew every three years. The DEA conducts periodic inspections of certain registered establishments that handle controlled substances. Obtaining and maintaining the necessary registrations may result in delay of the importation, manufacturing or distribution of COMP360. Furthermore, failure to maintain compliance with the CSA, particularly non-compliance resulting in loss or diversion, can result in regulatory action that could have a material adverse effect on our business, financial condition and results of operations. The DEA may seek civil penalties, refuse to renew necessary registrations, or initiate proceedings to restrict, suspend or revoke those registrations. In certain circumstances, violations could lead to criminal proceedings.

•State-controlled substances laws. Individual U.S. states have also established controlled substance laws and regulations. Though state-controlled substances laws often mirror federal law, because the states are separate jurisdictions, they may separately schedule COMP360. While some states automatically schedule a drug based on federal action, other states schedule drugs through rule making or a legislative action. State scheduling may delay commercial sale of any product for which we obtain federal regulatory approval and adverse scheduling could have a material adverse effect on the commercial attractiveness of such product. We or our partners must also obtain separate state registrations, permits or licenses in order to be able to obtain, handle, and distribute controlled substances for clinical trials or commercial sale, and failure to meet applicable regulatory requirements could lead to enforcement and sanctions by the states in addition to those from the DEA or otherwise arising under federal law.

•Clinical trials. Because our investigational COMP360 psilocybin treatment contains psilocybin, to conduct clinical trials with COMP360 in the United States prior to approval, each of our research sites must submit a research protocol to the DEA and obtain and maintain a DEA researcher registration that will allow those sites to handle and dispense COMP360 and to obtain the product from our importer. If the DEA delays or denies the grant of a researcher registration to one or more research sites, the clinical trial could be significantly delayed, and we could lose clinical trial sites. The importer for the clinical trials must also obtain a Schedule I importer registration and an import permit for each import. We do not currently conduct any manufacturing or repackaging/relabeling of either COMP360 or its active ingredients (i.e., psilocybin) in the United States. COMP360 is imported in its fully-finished, packaged and labeled dosage form.

•Importation. If COMP360 is approved and classified as a Schedule II, III or IV substance, an importer can import it for commercial purposes if it obtains an importer registration and files an application for an import permit for each import. The DEA provides annual assessments/estimates to the International Narcotics Control Board, which guides the DEA in the amounts of controlled substances that the DEA authorizes to be imported. The failure to identify an importer or obtain the necessary import authority, including specific quantities, could affect the availability of COMP360 and have a material adverse effect on our business, results of operations and financial condition. In addition, an application for a Schedule II importer registration must be published in the Federal Register, and there is a waiting period for third-party comments to be submitted. It is always possible that adverse comments may delay the grant of an importer registration. If COMP360 is approved and classified as a Schedule II controlled substance, federal law may prohibit the import of the substance for commercial purposes. If COMP360 is listed as a Schedule II substance, we will not be allowed to import the drug for commercial purposes unless the DEA determines that domestic supplies are inadequate or there is inadequate domestic competition among domestic manufacturers for the substance as defined by the DEA. Moreover, Schedule I controlled substances, including psilocybin and psilocin, have never been registered with the DEA for importation for commercial purposes, only for scientific and research needs. Therefore, if neither COMP360 nor its drug substance could be imported, COMP360 would have to be wholly

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manufactured in the United States, and we would need to secure a manufacturer that would be required to obtain and maintain a separate DEA registration for that activity.

•Manufacture in the United States. If, because of a Schedule II classification or voluntarily, we were to conduct manufacturing or repackaging/relabeling in the United States, our contract manufacturers would be subject to the DEA’s annual manufacturing and procurement quota requirements. Additionally, regardless of the scheduling of COMP360, the active ingredient in the final dosage form is currently a Schedule I controlled substance and would be subject to such quotas as this substance could remain listed on Schedule I. The annual quota allocated to us or our contract manufacturers for the active ingredient in COMP360 may not be sufficient to complete clinical trials or meet commercial demand. Consequently, any delay or refusal by the DEA in establishing our, or our contract manufacturers’, procurement and/or production quota for controlled substances could delay or stop our clinical trials or product launches, which could have a material adverse effect on our business, financial position and results of operations.

•Distribution in the United States. If COMP360 is scheduled as Schedule II, III or IV, we would also need to identify wholesale distributors with the appropriate DEA registrations and authority to distribute COMP360 and any future therapeutic candidates. These distributors would need to obtain Schedule II, III or IV distribution registrations. This limitation in the ability to distribute COMP360 more broadly may limit commercial uptake and could negatively impact our prospects. The failure to obtain, or delay in obtaining, or the loss of any of those registrations could result in increased costs to us. If COMP360 is a Schedule II drug, participants in our supply chain may have to maintain enhanced security with alarms and monitoring systems and they may be required to adhere to recordkeeping and inventory requirements. This may discourage some pharmacies from carrying the product. In addition, COMP360 could be determined to have a high potential for abuse and therefore required to be administered at our trial sites, which could limit commercial uptake. Furthermore, state and federal enforcement actions, regulatory requirements, and legislation intended to reduce prescription drug abuse, such as the requirement that physicians consult a state prescription drug monitoring program, may make physicians less willing to prescribe, and pharmacies to dispense, Schedule II products.

•Controlled Drug Status in the United Kingdom. Psilocybin and psilocin are “controlled drugs” in the UK, as they are listed under Schedule 1 of the UK’s Misuse of Drugs Regulations 2001 and are classified as Class A controlled substances under the Misuse of Drugs Act 1971. Substances listed under Schedule 1 of the Misuse of Drugs Regulations 2001 are considered to have little or no therapeutic benefit and are the most strictly controlled. These substances can therefore only be imported, exported, produced and supplied under a license issued by the UK Government’s Home Office. Psilocybin and psilocin may never be rescheduled under the Misuse of Drugs Regulations 2001, or reclassified under the UK’s Misuse of Drugs Act 1971.

The potential reclassification of psilocybin and psilocin in the United States could create additional regulatory burdens on our operations and negatively affect our results of operations.

If psilocybin and/or psilocin, other than the 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 psilocybin and psilocin would most likely be improved. However, rescheduling psilocybin and psilocin may materially alter enforcement policies across many federal 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 the FDCA. The FDA’s responsibilities include regulating the ingredients as well

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as the marketing and labeling of drugs sold in interstate commerce. Because it is currently illegal under federal law to produce and sell psilocybin and psilocin, and because there are no federally recognized medical uses, the FDA has historically deferred enforcement related to psilocybin and psilocin to the DEA. If psilocybin and psilocin 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 could threaten or have a materially adverse effect on our business.

COMP360 contains controlled substances, the use of which may generate public controversy. Adverse publicity or public perception regarding psilocybin or our current or future investigational treatments using psilocybin may negatively influence the success of these treatments.

Treatments 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, COMP360 and any future therapeutic candidates we may develop. Opponents of these treatments 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 treatments. For example, we may face media-communicated criticism directed at our clinical development program. Adverse publicity from psilocybin misuse or risky behavior associated with recreational use of psilocybin may adversely affect the commercial success or market penetration achievable by our investigational COMP360 psilocybin treatment. Anti-psychedelic protests have historically occurred and may occur in the future 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, our investigational COMP360 psilocybin treatment or any future therapeutic candidates.

If COMP360 or any future therapeutic candidates are approved for commercial sale, we will be highly dependent upon consumer perceptions of the safety and quality of our treatments. We may face limited adoption if third-party treatment sites, therapists, and patients are unwilling to try such a novel treatment. There has been a history of negative media coverage regarding psychedelic substances, including psilocybin, which may affect the public’s perception of our treatments. In addition, psilocybin 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 treatments or any similar treatments 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 treatments or any similar treatments 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 treatments. Any increased scrutiny could delay or increase the costs of obtaining regulatory approval for COMP360 or any future therapeutic candidates.

Clinical drug development is a lengthy and expensive process with uncertain timelines and uncertain outcomes. If clinical trials of COMP360 or any future therapeutic candidates are prolonged or delayed, we or our current or future collaborators may be unable to obtain required regulatory approvals, and therefore we will be unable to commercialize our investigational COMP360 psilocybin treatment or any future therapeutic candidates on a timely basis or at all, which will adversely affect our business.

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Clinical testing is expensive and can take many years to complete, and its outcome is inherently uncertain. Failure can occur at any time during the clinical trial process and our future clinical trial results may not be successful.

We may experience delays in completing our Phase 3 clinical program of COMP360 psilocybin treatment in TRD, completing our ongoing Phase 2 clinical trials in PTSD and anorexia nervosa and initiating or completing additional clinical trials. For example, we experienced some delays in our Phase 2 clinical trial for anorexia nervosa due to challenges in recruiting and screening participants for our Phase 2 study in anorexia nervosa, which resulted in a delay and amendments to our trial protocols and adjustments to our procedures. To address these challenges, we amended the trial protocol and adjusted our procedures. We may also experience numerous unforeseen events, and in some cases have experienced such events, during our clinical trials that could delay or prevent our ability to receive marketing approval or commercialize our investigational COMP360 psilocybin treatment or any future therapeutic candidates, including:

•delays in or failure to obtain regulatory approval to commence or modify a trial, including the imposition of a temporary or permanent clinical hold by regulatory authorities for a number of reasons, including after review of an Investigational New Drug Application, or IND, or amendment, clinical trial application, or CTA, or amendment, or equivalent application or amendment, as a result of a finding that the trial presents unreasonable risk to clinical trial participants or a negative finding from an inspection of our clinical trial operations or study sites, or the occurrence of a suspected, unexpected serious adverse reaction, or SUSAR, which we have experienced in the past, or serious adverse reaction, or SAE, during our clinical trials or investigator-initiated studies, or IISs, using COMP360;

•delays in or failure to reach agreement on acceptable terms with prospective contract research organizations, or CROs, and clinical trial sites, the terms of which can be subject to extensive negotiation and may vary significantly among different CROs and trial sites;

•delays in or failure to obtain institutional review board, or IRB, or ethics committee approval at each site;

•delays in or failure to recruit and enroll a sufficient number of suitable patients to participate in a trial;

•failure to have patients complete a trial or return for post-treatment follow-up;

•clinical sites deviating from trial protocol or dropping out of a trial;

•challenges related to conducting adequate and well-controlled clinical trials, including designing an appropriate comparator arm in studies given the potential difficulties related to maintaining the blinding during the trial or placebo or nocebo effects;

•adding new clinical trial sites;

•availability of adequately trained therapists and appropriate third-party clinical trial sites for the administration of COMP360 psilocybin treatment in our Phase 3 program and other clinical trials, including preparation, psilocybin administration and integration of the therapeutic experience;

•sufficiency of any supporting digital services that may form part of the preparation, integration or long-term follow-up relating to any drug we develop;

•failure to contract for the manufacture of sufficient quantities of the underlying therapeutic substance for use in clinical trials in a timely manner;

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•third-party actions claiming infringement by our investigational COMP360 psilocybin treatment or any future therapeutic candidates in clinical trials and obtaining injunctions interfering with our progress;

•safety or tolerability concerns which could cause us or our collaborators, as applicable, to suspend or terminate a trial if we or our collaborators find that the participants are being exposed to unacceptable health risks;

•changes in regulatory requirements, policies and guidelines, including the legislative proposals in the European Union related to pharmaceutical product development and marketing currently under debate, which, once approved, will replace the current European Union regulatory framework for medicines;

•lower than anticipated retention rates of patients and patients in clinical trials;

•our third-party research contractors failing to comply with regulatory requirements or meet their contractual obligations to us in a timely manner, or at all;

•delays in establishing the appropriate dosage levels in clinical trials;

•delays in our clinical trials due to public health crises, such as the COVID-19 pandemic, due to factors such as a decrease in the willingness or availability of patients to enroll in our clinical trials and challenges in procuring sufficient supplies of the underlying therapeutic substance;

•the quality or stability of the underlying therapeutic substance falling below acceptable standards; and

•business interruptions resulting from geo-political actions, including war and terrorism, natural disasters including earthquakes, typhoons, floods and fires, pandemics, or failures or significant downtime of our information technology systems resulting from cyber-attacks on such systems or otherwise.

We could encounter delays if a clinical trial is suspended or terminated by us, by the institutional review boards, or IRBs of the institutions in which such trials are being conducted or ethics committees, by the Data Review Committee, or DRC, or Data Safety Monitoring Board for such trial or by the FDA, the EMA, the MHRA or other regulatory authorities or if the DEA registration of an investigator or site conducting the clinical trial is revoked. Such authorities may impose such a suspension or termination due to a number of factors, including failure to conduct the clinical trial in accordance with regulatory requirements or our clinical protocols, inspection of the clinical trial operations or trial site by the FDA, the EMA, the MHRA or other regulatory authorities resulting in the imposition of a clinical hold, unforeseen safety issues or adverse side effects, including any SUSARs or SAEs which have in the past or may in the future occur in our trials or any IISs or other studies using COMP360 and those relating to the class to which COMP360 or any future therapeutic candidates belong, failure to demonstrate a benefit from using a drug, changes in governmental regulations or administrative actions or lack of adequate funding to continue the clinical trial. If we experience delays in the completion of, or termination of, any clinical trial of COMP360 or any future therapeutic candidates, the commercial prospects of our investigational COMP360 psilocybin treatment or any future therapeutic candidates will be harmed, and our ability to generate revenue from any such therapeutic candidates will be delayed. In addition, any delays in completing our clinical trials will likely increase our costs, slow down COMP360 or any future therapeutic candidate development and approval process and jeopardize our ability to commence sales and generate revenue. Moreover, if we make changes to COMP360 or any future therapeutic candidates, we may need to conduct additional studies to bridge such modified therapeutic candidates to earlier versions, which could delay our clinical development plan or marketing approval for our investigational COMP360 psilocybin treatment or any future therapeutic candidates. Significant clinical trial delays could also allow our competitors to bring treatments to market before we do or

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shorten any periods during which we have the exclusive right to commercialize our investigational COMP360 psilocybin treatment or any future therapeutic candidates and impair our ability to commercialize our investigational COMP360 psilocybin treatment or any future therapeutic candidates and may harm our business and results of operations.

Any of these occurrences may harm our business, financial condition and prospects significantly. In addition, many of the factors that cause, or lead to, a delay in the commencement or completion of clinical trials may also ultimately lead to the denial of regulatory approval of COMP360 or any future therapeutic candidates or result in the development of our investigational COMP360 psilocybin treatment or any future therapeutic candidates being stopped early.

Our clinical trials may fail to demonstrate substantial evidence of the safety and effectiveness of COMP360 or any future product candidates that we may identify and pursue, which would prevent, delay or limit the scope of regulatory approval and commercialization.

Before obtaining regulatory approvals for the commercial sale of our investigational COMP360 psilocybin treatment or future therapeutic candidates, we must demonstrate through lengthy, complex and expensive preclinical studies and clinical trials that the applicable therapeutic candidate is both safe and effective for use in each target indication. A therapeutic candidate must demonstrate an adequate risk versus benefit profile in its intended patient population and for its intended use.

Clinical testing is expensive and can take many years to complete, and its outcome is inherently uncertain. Failure can occur at any time during the clinical development process, including during Phase 3 pivotal trials, and, because our investigational COMP360 psilocybin treatment is our only product in clinical development, there is a high risk of failure and we may never succeed in developing marketable products. Most product candidates that begin clinical trials are never approved by regulatory authorities for commercialization. We have limited experience in managing late-stage clinical trials; our Phase 3 pivotal trials for COMP360 in TRD represent our first pivotal trials and we may not be able to successfully execute our Phase 3 pivotal trials.

We cannot be certain that our Phase 3 pivotal trials for COMP360 in TRD, our ongoing phase 2 trials or any other future clinical trials will be successful. Clinical trials that we conduct may not demonstrate the efficacy and safety necessary to obtain regulatory approval to market our investigational COMP360 psilocybin treatment. In some instances, there can be significant variability in safety or efficacy results between different clinical trials of the same therapeutic candidate due to numerous factors, including changes in trial procedures set forth in protocols, differences in the size and type of the patient populations, changes in and adherence to the clinical trial protocols and the rate of dropout among clinical trial participants. If the results of our ongoing or future clinical trials are inconclusive with respect to the efficacy of COMP360, if we do not meet the clinical endpoints with statistical and clinically meaningful significance, or if there are safety concerns associated with COMP360, we may be delayed in obtaining marketing approval, or we may never obtain marketing approval. Any safety concerns observed in any one of our clinical trials in our targeted indications could limit the prospects for regulatory approval of COMP360 in those and other indications, which could have a material adverse effect on our business, financial condition and results of operations.

Even if our clinical trials are successfully completed, preclinical and clinical data are often susceptible to varying interpretations and analyses and we cannot guarantee that the FDA, the EMA or comparable foreign regulatory authorities will interpret the results as we do, or agree that our clinical trials have been appropriately designed or powered to demonstrate the safety and efficacy of COMP360. Accordingly, more trials could be required before we submit COMP360 for approval. To the extent that the results of the trials are not satisfactory to the FDA, the EMA or comparable foreign regulatory authorities for support of a marketing application, approval of COMP360 may be significantly delayed, or we may be required to expend significant resources, which may not be available to us, to conduct additional trials in support of potential approval of COMP360. Moreover, results acceptable to support approval in one jurisdiction may be deemed inadequate by another

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regulatory authority to support regulatory approval in that other jurisdiction. Due to the inherent risk in the development of therapeutic substances, there is a significant likelihood that COMP360 and any future therapeutic candidates will not successfully complete development and receive approval. Many other companies that believed their therapeutic candidates performed satisfactorily in preclinical studies and clinical trials have nonetheless failed to obtain regulatory approval for the marketing of their product. If we do not receive regulatory approvals for COMP360 or future therapeutic candidates, we may not be able to continue our operations. Even if regulatory approval is secured for COMP360 or any future therapeutic candidate, the terms of such approval may limit the scope and use of a specific therapeutic candidate, which may also limit its commercial potential.

Interim, top-line and preliminary data from our clinical trials that we announce or publish from time to time may change as more patient data become available and are subject to audit and verification procedures that could result in material changes in the final data. These data may not be sufficient to support regulatory submissions or approvals.

We have in the past published and, from time to time in the future we may publish interim, top-line or preliminary data from our clinical trials. For example, in December 2023, we announced an initial data readout, based on monitoring patients at 24 hours post COMP360 administration, from our Phase 2 open-label study evaluating the safety and tolerability of COMP360 psilocybin treatment in patients with PTSD as a result of trauma experienced as adults. The study design provides for 12-week monitoring period and we expect to announce safety and efficacy data from the completed study in spring 2024. The final safety data may not be consistent with the initial data at 24-hours. We may decide to conduct an interim analysis of the data after a certain number or percentage of subjects have been enrolled, but before completion of the trial. Similarly, we may report top-line or preliminary results of primary and key secondary endpoints before the final trial results are completed. Interim, top-line and preliminary data from our clinical trials may change as more patient data or analyses become available and are not necessarily predictive of final results. Further interim, top-line and preliminary data are subject to the risk that one or more of the clinical outcomes may materially change as patient enrollment continues, more patient data become available and we issue our final clinical trial report. Interim, top-line and preliminary 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 published. As a result, interim, top-line and preliminary data should be viewed with caution until the final data are available. Material adverse changes in the final data compared to the interim data could significantly harm our business prospects or cause the price of our stock to decline.

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 approvability or commercialization of the particular therapeutic candidate and our company in general, and regulatory agencies may request further data from us. In addition, 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 therapeutic candidate. If the top-line data that we report differ from actual results, or if others, including regulatory authorities, disagree with the conclusions reached, our ability to obtain approval for, and commercialize COMP360 or any future product candidate, our business, operating results, prospects or financial condition may be harmed.

The regulatory approval process of the FDA, the EMA, the MHRA and comparable foreign authorities are lengthy, time-consuming and inherently unpredictable, and if we are ultimately unable to obtain regulatory approval for COMP360 and any future therapeutic candidates, our business will be substantially harmed.

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We have not previously submitted a new drug application, or NDA, to the FDA, or a marketing authorization application, or MAA, to the EMA or the MHRA, and have not obtained regulatory approval for COMP360. Before obtaining regulatory approvals for the commercial sale of COMP360 or any future therapeutic candidates, we must demonstrate through lengthy, complex and expensive preclinical testing and clinical trials that COMP360 and any future therapeutic candidates are both safe and effective for use in each target indication. Clinical testing is expensive and can take many years to complete, and its outcome is inherently uncertain. Failure can occur at any time during the clinical trial process, and while COMP360 is in a late stage of development, there continues to be a high risk of failure and we may never succeed in developing marketable products.

The time required to obtain approval by the FDA, the EMA, the MHRA and comparable foreign authorities is unpredictable but typically takes many years following the commencement of clinical trials and depends upon numerous factors, including the substantial discretion of the regulatory authorities. In addition, approval policies, regulations, or the type and amount of clinical data necessary to gain approval may change during the course of a therapeutic candidate’s clinical development and may vary among jurisdictions. For example, we cannot be certain of the impact on our therapeutic candidates of the legislative proposals by the European Commission in the European Union related to pharmaceutical product development and marketing currently under debate, which, once approved, will replace the current European Union regulatory framework for medicines. We are conducting a Phase 3 clinical program for COMP360 in TRD. We have Breakthrough Therapy Designation and have had dialogue with FDA regarding our Phase 3 trial design, including certain protocol amendments that we implemented in the first half of 2023. We anticipate having on-going dialogue with FDA throughout the conduct of the Phase 3 trials. In June 2023, the FDA published draft guidance regarding the nonclinical, clinical and safety considerations, as well as abuse potential assessment and risk mitigation and public health considerations for conducting trials for psychedelics, such as psilocybin. We believe our Phase 3 clinical program reflects the key principles set forth in the draft guidance. We continue to conduct our Phase 3 clinical program in accordance with our previously announced study design. However, FDA may disagree with our study design or conduct, and may make recommendations or request changes in the design or conduct of our pivotal programs that may require us to conduct additional clinical trials or otherwise delay our Phase 3 clinical program or may impact the review process for our new drug application for COMP360. It is possible that neither COMP360 nor any future therapeutic candidates we may seek to develop in the future will ever obtain regulatory approval.

COMP360 or any future therapeutic candidates could fail to receive regulatory approval from the FDA, the EMA, the MHRA or comparable foreign regulatory authorities or be precluded from commercial marketing for many reasons, including the following:

•the FDA, the EMA, the MHRA or comparable foreign regulatory authorities may disagree with, question or request changes in the size, design or implementation of our clinical trials;

•the FDA, the EMA, the MHRA or comparable foreign regulatory authorities may determine that COMP360 or any future therapeutic candidates are not safe and effective, only moderately effective, or have undesirable or unintended side effects, toxicities, or other characteristics that preclude our obtaining marketing approval or prevent or limit commercial use;

•the results of clinical trials may not meet the level of statistical significance required by the FDA, the EMA, the MHRA or comparable foreign regulatory authorities for approval;

•we may be unable to demonstrate that our investigational COMP360 psilocybin treatment or any future therapeutic candidate’s clinical and other benefits outweigh its safety risks;

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•the FDA, the EMA, the MHRA or comparable foreign regulatory authorities may disagree with our interpretation of data from preclinical studies or clinical trials;

•the data collected from clinical trials of our investigational COMP360 psilocybin treatment or any future therapeutic candidates may not be sufficient to support the submission of an NDA or other submission, or to obtain regulatory approval in the United States or elsewhere;

•the FDA, the EMA, the MHRA or comparable foreign regulatory authorities may find deficiencies with or fail to approve the manufacturing processes or facilities of third-party manufacturers with which we contract for clinical and commercial supplies;

•the approval policies or regulations of the FDA, the EMA, the MHRA or comparable foreign regulatory authorities may significantly change in a manner rendering our clinical data insufficient for approval; and

•the potential risk of our novel treatment and delivery method, including the use of third-party clinical trial sites and therapists.

This lengthy approval process, as well as the unpredictability of future clinical trial results, may result in our failing to obtain regulatory approval to market any COMP360 or any future therapeutic candidates, which would significantly harm our business, results of operations and prospects. The FDA, the EMA, the MHRA and other comparable foreign authorities have substantial discretion in the approval process and determining when or whether regulatory approval will be obtained for any of COMP360 or any future therapeutic candidates. Even if we believe the data collected from clinical trials of COMP360 or any future therapeutic candidates are promising, such data may not be sufficient to support approval by the FDA, the EMA, the MHRA or any other regulatory authority. If COMP360 or any future therapeutic candidates fails to obtain approval on the basis of any applicable condensed regulatory approval process, this will prevent such therapeutic candidates from obtaining approval on a shortened time frame, or at all, resulting in increased expenses which would materially harm our business.

In addition, even if we were to obtain approval, regulatory or pricing authorities may approve COMP360 or any future therapeutic candidates for fewer or more limited indications than we request, may not approve the price we intend to charge for our treatments, may grant approval contingent on the performance of costly post-marketing clinical trials, or may approve a therapeutic candidate with a label that does not include the labeling claims necessary or desirable for the successful commercialization of that therapeutic candidate. For example, esketamine, a drug targeting major depressive disorder, or MDD, is only available through a Risk Evaluation and Mitigation Strategy, or REMS, program, under the applicable FDA regulations and, as is required for antidepressants, has a black box warning for increased risk of suicidal thoughts and behaviors in pediatric and young adult patients. Any of the foregoing scenarios may have a negative impact on the commercial prospects for our investigational COMP360 psilocybin treatment or any future therapeutic candidates.

Even if COMP360 or any future therapeutic candidates obtain regulatory approval, we will be subject to ongoing obligations and continued regulatory review, which may result in significant additional expense. Additionally, any such therapeutic candidates, if approved, could be subject to labeling and other restrictions and market withdrawal and we may be subject to penalties if we fail to comply with regulatory requirements or experience unanticipated problems with our investigational COMP360 psilocybin treatment or any future therapeutic candidates.

If the FDA, the EMA, the MHRA or a comparable foreign regulatory authority approves COMP360 or any future therapeutic candidates, the manufacturing processes, labeling, packaging, distribution, adverse event reporting, storage, advertising, promotion and recordkeeping for the treatment and underlying drug substance will be subject to extensive and

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ongoing regulatory requirements. These requirements include submissions of safety and other post-marketing information and reports, registration, as well as continued compliance with current good manufacturing practices, or cGMPs, and with good clinical practices, or GCPs, for any clinical trials that we conduct post-approval, as well as applicable product tracking and tracing requirements, all of which may result in significant expense and limit our ability to commercialize such treatments. Additionally, a company may not promote “off-label” uses for its drug products. An off-label use is the use of a product for an indication that is not described in the product’s FDA-approved label in the United States. or for uses in other jurisdictions that differ from those approved by the applicable regulatory agencies. Physicians, on the other hand, may prescribe products for off-label uses. Although the FDA and other regulatory agencies do not regulate a physician’s choice of drug treatment made in the physician’s independent medical judgment, they do restrict promotional communications from companies or their sales force with respect to off-label uses of products for which marketing clearance has not been issued. Later discovery of previously unknown problems with any approved therapeutic candidate, 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, among other things:

•restrictions on the labeling, distribution, marketing or manufacturing of COMP360 or any future therapeutic candidates, withdrawal of the product from the market, or product recalls;

•untitled and warning letters, or holds on clinical trials;

•refusal by the FDA, the EMA, the MHRA or other foreign regulatory body to approve pending applications or supplements to approved applications we filed or suspension or revocation of license approvals;

•requirements to conduct post-marketing studies or clinical trials;

•restrictions on coverage by third-party payors;

•fines, restitution or disgorgement of profits or revenue;

•suspension or withdrawal of marketing approvals;

•product seizure or detention, or refusal to permit the import or export of the product; and

•injunctions or the imposition of civil or criminal penalties.

In addition, any regulatory approvals that we receive for COMP360 or any future therapeutic candidates may also be subject to limitations on the approved indicated uses for which our COMP360 psilocybin treatment 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 such therapeutic candidates. For instance, we believe that COMP360, if approved, would be subject to a REMS program, under the applicable FDA regulations. REMS programs are costly and time-consuming for providers to comply with, involving high administrative burden, which could delay or limit our ability to commercialize our investigational COMP360 psilocybin treatment.

If there are changes in the application of legislation, regulations or regulatory policies, or if problems are discovered with our investigational COMP360 psilocybin treatment or our manufacture of an underlying therapeutic substance, or if we or one of our distributors, licensees or co-marketers fails to comply with regulatory requirements, the regulators could take various actions. These include imposing fines on us, imposing restrictions on the therapeutic or its manufacture and requiring us to recall or remove the therapeutic from the market. The regulators could also suspend or withdraw our marketing authorizations,

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requiring us to conduct additional clinical trials, change our therapeutic labeling or submit additional applications for marketing authorization. If any of these events occurs, our ability to sell such COMP360 psilocybin treatment may be impaired, and we may incur substantial additional expense to comply with regulatory requirements, which could materially adversely affect our business, financial condition and results of operations.

COMP360 and any future therapeutic candidates we may develop may have serious adverse, undesirable or unacceptable side effects which may delay or prevent marketing approval. If such side effects are identified during the development of COMP360 or any future therapeutic candidates or following approval, if any, we may need to abandon our development of such therapeutic candidates, the commercial profile of any approved label may be limited, or we may be subject to other significant negative consequences.

Undesirable side effects that may be caused by COMP360 or any future therapeutic candidates could cause us or regulatory authorities to interrupt, delay or halt clinical trials or result in clinical holds and could result in a more restrictive label, a requirement that we implement a REMS plan to ensure that the benefits of the treatment outweigh its risks, or the delay or denial of regulatory approval by the FDA, the EMA, the MHRA or other comparable foreign authorities. We or regulatory authorities may also learn of and take similar actions based on side effects related to COMP360 or compounds similar to COMP360 or any future therapeutic candidates in studies not conducted by us, including in IISs or studies conducted by other sponsors, from spontaneous reports of use of psilocybin outside of the clinical trial setting or from safety reports in literature.

The results of future clinical studies may show that COMP360 or any future therapeutic candidates cause undesirable or unacceptable side effects or even death. For example, there were a number of serious treatment emergent adverse events reported with the results of our Phase 2b clinical trial in TRD. In addition, there may be serious adverse events reported in healthy volunteer studies. There can be no assurance that deaths or serious side effects will not occur, even in a clinical setting. In the event serious side effects occur, our trials could be suspended or terminated and the FDA, the EMA, the MHRA or comparable foreign regulatory authorities could order us to cease further development of or deny approval of COMP360 or any future therapeutic candidates for any or all targeted indications. The drug-related side effects could affect patient recruitment or the ability of enrolled patients to complete the trial or result in potential product liability claims. Further, because of the high variability in how different individuals react to psilocybin, certain clinical trial participants, including volunteers, may have negative experiences with the treatment that could subject us to liability or, if publicized, reputational harm. Any of these occurrences may harm our business, financial condition and prospects significantly.

Clinical trials are conducted in representative samples of the potential patient population which may have significant variability. Even if we receive regulatory approval for COMP360 or any future therapeutic candidates, we will have tested them in only a limited number of patients during our clinical trials. Clinical trials are by design based on a limited number of subjects and of limited duration for exposure to the treatment used to determine whether, on a potentially statistically significant basis, the target safety and efficacy profile of any such therapeutic candidate can be achieved. As with the results of any statistical sampling, we cannot be sure that all side effects of COMP360 or any future therapeutic candidates may be uncovered, and it may be the case that only with a significantly larger number of patients exposed to such therapeutic candidate for a longer duration, may a more complete safety profile be identified. Further, even larger clinical trials may not identify rare serious adverse effects or the duration of such studies may not be sufficient to identify when those events may occur. If our applications for marketing are approved and more patients begin to use our COMP360 psilocybin treatment, new risks and side effects associated with our treatments may be discovered. There have been other products and treatments that have been approved by the regulatory authorities but for which safety concerns have been uncovered following approval. Such

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safety concerns have led to labelling changes or withdrawal of treatments from the market, and our investigational COMP360 psilocybin treatment and any future therapeutic candidates may be subject to similar risks. We might have to withdraw or recall our investigational COMP360 psilocybin treatment and any future therapeutic candidates from the marketplace. We may also experience a significant drop in the potential future sales of our investigational COMP360 psilocybin treatment or any future therapeutic candidates if and when regulatory approvals for such treatment are obtained, experience harm to our reputation in the marketplace or become subject to lawsuits, including class actions. Any of these results could decrease or prevent any sales of our approved therapeutic candidates, if any, or substantially increase the costs and expenses of commercializing and marketing our investigational COMP360 psilocybin treatment and any future therapeutic candidates.

Additionally, if our investigational COMP360 psilocybin treatment or any future therapeutic candidates receive marketing approval and we or others later identify undesirable or unacceptable side effects caused by such therapeutic candidates, a number of potentially significant negative consequences could result, including the following:

•regulatory authorities may withdraw approvals of such treatments and require us to take our approved therapeutic candidates, if any, off the market;

•regulatory authorities may require the addition of labeling statements, specific warnings, a contraindication or field alerts to physicians and pharmacies;

•regulatory authorities may require a medication guide outlining the risks of such side effects for distribution to patients, or that we implement a REMS plan to ensure that the benefits of the therapeutic candidate outweigh its risks;

•we may be required to change the way the COMP360 psilocybin treatment is administered, conduct additional clinical trials or change the labeling of the therapeutic candidate;

•we may be subject to limitations on how we may promote the therapeutic candidate;

•sales of the COMP360 psilocybin treatment may decrease significantly;

•we may be subject to litigation or product liability claims; and

•our reputation may suffer.

Any of these events could prevent us or our potential future collaborators from achieving or maintaining market acceptance of the affected therapeutic candidate or could substantially increase commercialization costs and expenses, which in turn could delay or prevent us from generating significant revenue from the sale of our investigational COMP360 psilocybin treatment or any future therapeutic candidates.

Even if we obtain FDA, EMA or MHRA approval for COMP360 or any future therapeutic candidates that we may identify and pursue in the United States, Europe or the UK, we may never obtain approval to commercialize any such therapeutic candidates outside of those jurisdictions, which would limit our ability to realize their full market potential.

In order to market any products outside of the United States, we must establish and comply with numerous and varying regulatory requirements of other countries regarding safety and effectiveness. 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

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approval will be obtained in any other country. Approval processes vary among countries and can involve additional product testing and validation and additional or different administrative review periods from those in the United States, including additional preclinical 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 therapeutic candidate must 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 approval.

Seeking foreign regulatory approval could result in difficulties and costs and require additional preclinical studies or clinical trials which could be costly and time-consuming. Regulatory requirements can vary widely from country to country and could delay or prevent the introduction of our investigational COMP360 psilocybin treatment and any future therapeutic candidates in those countries. The foreign regulatory approval process may include all of the risks associated with obtaining FDA, EMA or MHRA approval. We do not have any therapeutic candidates approved for sale in any jurisdiction, including international markets, and we do not have experience in obtaining regulatory approval in international markets for COMP360 or any future therapeutic candidates. If we fail to comply with regulatory requirements in international markets or to obtain and maintain required approvals, or if regulatory approval in international markets is delayed, our target market will be reduced and our ability to realize the full market potential of our investigational COMP360 psilocybin treatment and any future therapeutic candidates will be harmed.

The results of preclinical studies and early-stage clinical trials of our investigational COMP360 psilocybin treatment or any future therapeutic candidates may not be predictive of the results of later stage clinical trials. Initial success in our ongoing clinical trials may not be indicative of results obtained when these trials are completed or in later stage trials.

Therapeutic candidates in later stages of clinical trials may fail to show the desired safety and efficacy traits despite having progressed through preclinical studies and initial clinical trials. Furthermore, there can be no assurance that any of our clinical trials will ultimately be successful or support further clinical development of COMP360 or any future therapeutic candidates. There is a high failure rate for drugs proceeding through clinical trials, including in Phase 3 pivotal trials. A number of companies in the pharmaceutical industry have suffered significant setbacks in clinical development even after achieving promising results in earlier studies.

Additionally, several of our past, planned and ongoing clinical trials utilize an “open-label” trial design. An “open-label” clinical trial is one where both the patient and investigator know whether the patient is receiving the investigational product candidate or either an existing approved drug or placebo. Most typically, open-label clinical trials test only the investigational product candidate and sometimes may 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. Open-label clinical trials may be subject to a “patient bias” where patients perceive their symptoms to have improved merely due to their awareness of receiving an experimental treatment. In addition, open-label clinical trials may be subject to an “investigator bias” where those assessing and reviewing the 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. The results from an open-label trial may not be predictive of future clinical trial results with any of our product candidates for which we include an open-label clinical trial when studied in a controlled environment with a placebo or active control.

Research and development of drugs targeting the central nervous system is particularly difficult, which makes it difficult to predict and understand why the drug has a positive effect on some patients but not others.

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Discovery and development of new drugs targeting central nervous system, or CNS, disorders are particularly difficult and time-consuming, evidenced by the higher failure rate for new drugs for CNS disorders compared with most other areas of drug discovery. Any such setbacks in our clinical development could have a material adverse effect on our business and operating results. In addition, our later stage clinical trials may present challenges related to conducting adequate and well-controlled clinical trials, including designing an appropriate comparator arm in trials given the potential difficulties related to maintaining the blinding during the trial or placebo or nocebo effects.

Due to the complexity of the human brain and the central nervous system, it can be difficult to predict and understand why a drug, including COMP360, may have a positive effect on some patients but not others and why some individuals may react to the drug differently from others. For example, the population of those suffering with TRD is large and heterogenous and individuals may have different levels of severity of TRD. These differences may further result in different reactions impacting the effectiveness of our investigational COMP360 psilocybin treatment which may cause the percentage of patients, if any, that go into remission to fluctuate. All of these factors may make it difficult to assess the prior use or the overall efficacy of our investigational COMP360 psilocybin treatment. In addition, certain diseases or conditions that we decide to target have in the past and may in the future present increased or unique challenges in clinical development. For example, drug development for anorexia nervosa is not well understood, and we have experienced challenges in recruiting and screening participants for our Phase 2 study in anorexia nervosa. We made amendments to our trial protocol to reduce the trial burden for this highly vulnerable patient population. Even with these protocol amendments, we have seen and expect to continue to see some recruitment challenges based on this patient population and the challenges with clinical study conduct. Moreover, these increased or unique challenges could ultimately impact our ability to seek and obtain regulatory approval in these conditions.

We depend on enrollment of patients in our clinical trials for COMP360 and any future therapeutic candidates. If we are unable to enroll patients in our clinical trials, our research and development efforts and business, financial condition and results of operations could be materially adversely affected.

Identifying and qualifying patients to participate in our clinical trials is critical to our success. Patient enrollment depends on many factors, including:

•the size of the patient population required for analysis of the trial’s primary endpoints and the process for identifying patients;

•identifying and enrolling eligible patients, including those willing to discontinue use of their existing medications;

•the design of the clinical protocol and the patient eligibility and exclusion criteria for the trial;

•safety profile, to date, of the therapeutic candidate under study;

•the willingness or availability of patients to participate in our trials, including due to the perceived risks and benefits, stigma or other side effects of use of a controlled substance;

•the willingness or availability of patients to participate in our trials, including due to any public health crisis such as the COVID-19 pandemic and the emergence of new COVID-19 variants;

•perceived risks and benefits of our approach to treatment of indication;

•the proximity of patients to clinical sites;

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•our ability to recruit clinical trial investigators with the appropriate competencies and experience;

•the availability of competing clinical trials;

•the availability of new drugs approved for the indication the clinical trial is investigating;

•clinicians’ and patients’ perceptions of the potential advantages of the drug being studied in relation to other available treatments, including any new treatments that may be approved for the indications we are investigating; and

•our ability to obtain and maintain patient informed consents.

Even once enrolled, we may be unable to retain a sufficient number of patients to complete any of our trials.

In addition, any negative results we may report in clinical trials of COMP360 or any future therapeutic candidates may make it difficult or impossible to recruit and retain patients in other clinical trials of that same therapeutic candidate. Delays in the enrollment for any clinical trial of COMP360 or any future therapeutic candidates will likely increase our costs, slow down COMP360 approval process and delay or potentially jeopardize our ability to commence sales of our investigational COMP 360 psilocybin treatment and generate revenue. For example, in our clinical trials for TRD, reviewing and verifying a participant’s medical records to confirm such participant meets the inclusion criteria for TRD is time-consuming and administratively burdensome, which can delay the screening process for our clinical trials. The steps we have taken to make this process more efficient may not be successful. We have experienced some delays in our Phase 2 clinical trial for anorexia nervosa due to challenges in recruiting and screening participants for our Phase 2 study in anorexia nervosa. To address these challenges, we made amendments to our trial protocol to reduce the trial burden for this highly vulnerable patient population. Even with these protocol amendments, we have seen and expect to continue to see some recruitment challenges based on this patient population and the challenges with clinical study conduct. As a result of these challenges, our original expectations regarding the timing of a data readout from this trial was pushed back. In addition, some of the factors that cause, or lead to, a delay in the commencement or completion of clinical trials may also ultimately lead to the denial of regulatory approval of COMP360 or any future therapeutic candidates.

Further, timely enrollment in clinical trials is reliant on clinical trial sites which may be adversely affected by global health matters, including, among other things, pandemics. For example, our clinical trial sites may be located in regions which may in the future be impacted by pandemics or public health crises. For example, in the past, enrollment in our trials was adversely affected as a result of the COVID-19 pandemic due to limited availability of participants, the inability of patients, therapists or physicians to participate in our trials, interruptions in supply chains and delays with regulators and other similar bodies. The conduct of our trials may continue to be adversely affected by future public health crises or pandemics, despite efforts to mitigate this impact.

We have never commercialized a therapeutic candidate before and may lack the necessary expertise, personnel and resources to successfully commercialize our treatments on our own or with suitable collaborators.

While we are currently assembling a sales and marketing infrastructure, we have limited organizational experience in the sale or marketing of therapeutic candidates. To achieve commercial success for any approved treatment, we must develop or acquire a sales and marketing organization, outsource these functions to third parties or enter into partnerships.

If our investigational COMP360 psilocybin treatment is approved for commercial sale, we plan on establishing our own market access and commercialization capabilities in primary markets in North America. In select geographies, we might also consider relying on the support of a Contract Sales Organization, or CSO, or enter into commercialization arrangements with

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companies with relevant commercialization capabilities. There are risks involved in establishing our own sales and marketing capabilities, as well as with entering into arrangements with third parties to perform these services. Even if we establish sales and marketing capabilities, we may fail to launch our treatments effectively or to market our treatments effectively since we have limited organizational experience in the sales and marketing of therapeutic substances. In addition, recruiting and training a sales force is expensive and time-consuming, and could delay any therapeutic launch. In the event that any such launch is delayed or does not occur for any reason, we would have prematurely or unnecessarily incurred these commercialization expenses, and our investment would be lost if we cannot retain or reposition our sales and marketing personnel. Factors that may inhibit our efforts to commercialize our treatments on our own include:

•our inability to train an adequate number of therapists to meet the demand for COMP360 psilocybin treatment;

•the ability of therapists at third-party treatment sites to perform their roles consistently with our training and our guidelines for the administration of our investigational COMP360 psilocybin treatment;

•our inability to recruit, train and retain effective market access and commercial personnel;

•the inability of commercial personnel to obtain access to or educate adequate numbers of physicians on the benefits of prescribing any future treatments;

•our inability to identify a sufficient number of treatment centers in third-party treatment sites to meet the demands of our treatments;

•the lack of complementary treatments to be offered by our commercial personnel, which may put us at a competitive disadvantage relative to companies with more extensive therapeutic lines;

•unforeseen costs and expenses associated with creating an independent market access and commercial organization; and

•costs of market access and commercialization above those anticipated by us.

If we enter into arrangements with third parties to perform market access and commercial services for any approved treatments, the revenue or the profitability of these revenues to us could be lower than if we were to commercialize any treatments that we develop ourselves. Such collaborative arrangements may place the commercialization of any approved treatments outside of our control and would make us subject to a number of risks including that we may not be able to control the amount or timing of resources that our collaborative partner devotes to our treatments or that our collaborator’s willingness or ability to complete its obligations, and our obligations under our arrangements may be adversely affected by business combinations or significant changes in our collaborator’s business strategy. For example, in December 2023, we entered into a collaboration agreement with Greenbrook TMS and there is substantial doubt regarding Greenbrook TMS’s ability to continue as a going concern due to recurring losses from operations, inability to increase cash flow and/or raise sufficient capital to support Greenbrook TMS’s operating activities and fund its cash obligations, repay indebtedness and satisfy Greenbrook TMS’s working capital needs and debt obligations. Greenbrook TMS’s willingness or ability to complete its obligations under the research collaboration agreement may be adversely affected by business combinations, restructurings or other corporate transactions, worsening of its financial position or significant changes in its strategy. We may not be successful in entering into arrangements with third parties to commercialize our treatments or may be unable to do so on terms that are favorable to us. Acceptable third parties may fail to devote the necessary resources and attention to commercialize our treatments effectively, to set up a sufficient number of treatment centers in third-party treatment sites, or to recruit, train and retain an

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adequate number of therapists to administer our treatments. In addition, we are exploring ways in which we can use digital technology to improve the patient experience and therapeutic outcomes of our treatments. Commercialization partners may lack incentives to promote our digital technology and we may face difficulties in implementing our digital technologies in third-party treatment sites through such third parties.

If we do not establish commercial capabilities successfully, either on our own or in collaboration with third parties, we may not be successful in commercializing our treatments, which in turn would have a material adverse effect on our business, prospects, financial condition and results of operations.

The future commercial success of our investigational COMP360 psilocybin treatment or any future therapeutic candidates will depend on the degree of market access and acceptance of our potential treatments among healthcare professionals, patients, healthcare payors, health technology assessment bodies and the medical community at large.

We may never have a product that is commercially successful. To date, we have no product authorized for marketing. Our investigational COMP360 psilocybin treatment requires further clinical investigation, regulatory review, significant market access and marketing efforts and substantial investment before it can produce any revenue. Furthermore, if approved, our COMP360 psilocybin treatment may not achieve an adequate level of acceptance by payors, health technology assessment bodies, healthcare professionals, patients and the medical community at large, and we may not become profitable. The level of acceptance we ultimately achieve may be affected by negative public perceptions and historical media coverage of psychedelic substances, including psilocybin. Because of this history, efforts to educate the medical community and third-party payors and health technologies assessment bodies on the benefits of our investigational COMP360 psilocybin treatment may require significant resources and may never be successful, which would prevent us from generating significant revenue or becoming profitable.

Market acceptance of our future treatments by healthcare professionals, patients, healthcare payors and health technology assessment bodies will depend on a number of factors, many of which are beyond our control, including, but not limited to, the following:

•acceptance by healthcare professionals, patients and healthcare payors of each treatment as safe, effective and cost-effective;

•changes in the standard of care for the targeted indications for any therapeutic candidate;

•the strength of sales, marketing and distribution support;

•potential product liability claims;

•the therapeutic candidate’s relative convenience, ease of use, ease of administration and other perceived advantages over alternative treatments;

•the prevalence and severity of adverse events or publicity;

•limitations, precautions or warnings listed in the summary of therapeutic characteristics, patient information leaflet, package labeling or instructions for use;

•the cost of treatment with COMP360 in relation to alternative treatments;

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•the steps that prescribers and dispensers must take, given that COMP360 includes a controlled substance, as well as the perceived risks based upon its controlled substance status;

•the ability to manufacture our product in sufficient quantities and yields;

•the availability and amount of coverage and reimbursement from healthcare payors, and the willingness of patients to pay out of pocket in the absence of healthcare payor coverage or adequate reimbursement;

•the willingness of the target patient population to try, and of healthcare professionals to prescribe, our COMP360 psilocybin treatment;

•any potential unfavorable publicity, including negative publicity associated with recreational or professional use or abuse of psilocybin or with adverse outcomes or side effects from the use of psilocybin such as unfavorable publicity related to use of psilocybin at Oregon state-licensed psilocybin service centers under the supervision of a state-licensed facilitator;

•any restrictions on the use, sale or distribution of our investigational COMP360 psilocybin treatment or any future therapeutic candidates, including through REMS;

•the extent to which treatments are approved for inclusion and reimbursed on formularies of hospitals and managed care organizations; and

•whether our treatments are designated under physician treatment guidelines or under reimbursement guidelines as a first-line, second-line, third-line or last-line treatment.

If our investigational COMP360 psilocybin treatment or any future therapeutic candidates fail to gain market access and acceptance, this will have a material adverse impact on our ability to generate revenue to provide a satisfactory, or any, return on our investments. Even if some treatments achieve market access and acceptance, the market may prove not to be large enough to allow us to generate significant revenue.

Our business and commercialization strategy for investigational COMP360 psilocybin treatment depends on our ability to identify, qualify, prepare, certify and support third-party treatment sites which will administer COMP360 psilocybin treatment. If we are unable to do so, our commercialization prospects would be limited and our business, financial condition and results of operations would be harmed.

If we are able to commercialize our investigational COMP360 psilocybin treatment or future treatments, our success will be dependent upon our ability to identify, qualify, prepare, certify and support third-party treatment sites that offer and administer our treatments. Our commercial model of delivering our investigational COMP360 psilocybin treatment will also involve third-party therapists before, during and after the COMP360 psilocybin administration session, which will be hosted in one of the third-party treatment sites. We intend to commercialize our investigational COMP360 psilocybin treatment and any future therapeutic candidates by building close relationships with qualified third-party treatment sites where these therapists will administer our investigational COMP360 psilocybin treatment. Because we expect our COMP360 psilocybin treatment to be subject to a REMS program and because we intend to work only with third-party sites and providers who agree to adhere strictly to our treatment protocols, we may face limitations on the number of sites available to administer our investigational COMP360 psilocybin treatment. Any such limitations could make it impracticable or impossible for some potential patients to

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access our investigational COMP360 psilocybin treatment, 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 a sufficient network of third-party treatment sites certified under applicable standards, including regional, national, state or other applicable standards as needed to render psilocybin therapeutic services, including the certifications that such third-party treatment sites may require, 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. We expect the therapists to be employed by the third-party treatment sites where the therapists administer our treatments. Third-party treatment sites could, for a number of reasons, demand higher payments for our treatments or take other actions to increase their income from selling our treatments, which could result in higher costs for payors and for our patients to get access to our treatments. For example, legal regimes may have higher levels of licensure which force us to contract with third-party treatment sites that demand higher payment rates to provide psilocybin therapeutic services. In addition, third-party treatment sites may have difficulty meeting regulatory or accreditation requirements.

Given the novel nature of our treatment, third-party treatment sites may face additional financial and administrative burdens in order to deliver any approved treatment, including adhering to a REMS plan in the United States or a Risk Management Program, or RMP, in Europe. The process for a third-party treatment site to obtain a certificate under a REMS plan can be very costly and time-consuming, which could delay a third-party treatment site’s ability to provide our treatments and materially adversely affect our commercialization trajectory. Furthermore, third-party treatment sites will need to ensure that they have the necessary infrastructure and equipment in order to deliver our investigational COMP360 psilocybin treatment, such as adequate audio-visual equipment, ancillary equipment and sufficient treatment rooms. This may deter third-party treatment sites from providing our therapeutic candidate and reduce our ability to expand our network and generate revenue. Our ability to develop and maintain satisfactory relationships with third-party treatment sites may otherwise be negatively impacted by other factors not associated with our operations and, in some instances, outside of our direct or indirect control, such as negative perceptions regarding the therapeutic use of psilocybin, changes in Medicare and/or Medicaid or commercial payors reimbursement levels and other pressures on healthcare providers and consolidation activity among hospitals, physician groups and the providers. Reimbursement levels may be inadequate to cover third-party treatment sites’ costs of delivering our investigational COMP360 psilocybin treatment. The failure to maintain or to secure new cost-effective contracts with third-party treatment sites may result in a loss of or inability to grow our network of third-party treatment sites, patient base, higher costs to our patients and us, healthcare provider network disruptions and/or difficulty in meeting regulatory or accreditation requirements, any of which could have a material adverse effect on our business, financial condition and results of operations.

We currently rely on specially trained therapists working at third-party clinical trial sites to administer our investigational COMP360 psilocybin treatment in our clinical trials and we expect this to continue upon approval, if any, of COMP360 or any future psychedelic-based drug candidates. If third-party sites fail to recruit and retain a sufficient number of therapists or effectively manage their therapists, our business, financial condition and results of operations would be materially harmed.

We currently administer our investigational COMP360 psilocybin treatment in our clinical trials through qualified third-party therapists working at third-party clinical trial sites. However, there are currently not enough trained therapists to carry out our investigational COMP360 psilocybin treatment at a commercial scale, and our efforts to facilitate training programs for therapists may be unsuccessful.

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While we currently provide training to the therapists and expect to continue providing training in the future (either directly or indirectly through third-party providers), we do not currently employ the therapists who deliver our treatments to patients and do not intend to do so in the future. Such therapists are typically employed by the third-party treatment sites. If our investigational COMP360 psilocybin treatment or any future therapeutic candidates are approved for commercialization, third-party treatment sites may demand substantial financial resources from us to recruit and retain a team of qualified therapists to administer our investigational COMP360 psilocybin treatment or any future therapeutic candidates. If the third-party treatment sites fail to recruit, train and retain a sufficient number of therapists or if a competitor develops a similar product that is effective without the use of therapists, our ability to offer and administer our treatments will be greatly harmed, which may in turn reduce the market acceptance rate of our treatments or limit our ability to grow our business. If this occurs, our commercialization prospects would be negatively affected and our business, financial condition and results of operations would be harmed.

Although we currently provide training and expect to continue providing training to the therapists (directly or through third-party providers), we generally rely on qualified and certified third-party treatment sites to manage the therapists and monitor the administration of our treatments and ensure that the administration process of our treatments comply with our established protocols. However, if not properly managed and supervised, there is a risk that therapists may deviate from our training protocols, fail to follow the guidelines we have established, or abuse patients during psilocybin administration sessions. The therapists might also administer unauthorized treatments to patients using illegal psilocybin compounds in “underground” clinics. Such illegal activities would put the patients at risk and subject us to potential liabilities, litigations, regulatory proceedings and reputational harm. If this were to occur, we may face serious setbacks for our commercialization process and our financial condition and results of operations would be materially harmed.

Commercialization of our COMP360 psilocybin treatment or other psychedelic-based drug candidates is dependent on our relationships with affiliated professional entities, which we do not own, to provide physician services, and our business would be adversely affected if those relationships were disrupted.

There is a risk that U.S. state authorities in some jurisdictions may find that our contractual relationships with our affiliated providers and our Centers of Excellence violate laws prohibiting the corporate practice of medicine and certain other health professions. These laws generally prohibit the practice of medicine and certain other health professions by lay persons or entities and are intended to prevent unlicensed persons or entities from interfering with or inappropriately influencing the professional judgment of clinicians and other health care practitioners. The professions subject to corporate practice restrictions and the extent to which each jurisdiction considers particular actions or contractual relationships to constitute improper influence of professional judgment vary across jurisdictions and are subject to change and evolving interpretations by state boards of medicine and other health professions and enforcement agencies, among others. As such, we must monitor our compliance with laws in every jurisdiction in which we operate on an ongoing basis and we cannot guarantee that subsequent interpretation of the corporate practice laws will not further circumscribe our business operations. State corporate practice restrictions also often impose penalties on health professionals for aiding a corporate practice violation, which could discourage clinicians or other licensed professionals from participating in our network of providers or Centers of Excellence. Any difficulty securing clinicians to participate in our network could impair our ability to provide treatments and could have a material adverse effect on our business.

Corporate practice restrictions exist in some form, whether by statute, regulation, professional board or attorney general guidance, or case law, in at least 42 U.S. states, though the broad variation between jurisdictions with respect to the application and enforcement of the doctrine makes establishing an exact count difficult. Because of the prevalence of corporate practice

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restrictions on medicine, we contract for provider services and other services provided by the Centers for Excellence through various agreements, such as service agreements, rather than employ providers. We expect that these relationships will continue, but we cannot guarantee that they will. The arrangement in which we have entered to comply with state corporate practice of medicine doctrines could subject us to additional scrutiny by federal and state regulatory bodies regarding federal and state fraud and abuse laws. In addition, a material change in our relationship with providers, whether resulting from a dispute among the entities, a change in government regulation, or the loss of these affiliations, could impair our ability to provide treatments and could have a material adverse effect on our business, financial condition and results of operations.

Changes in methods of therapeutic candidate manufacturing or formulation may result in additional costs or delay.

As therapeutic candidates are developed through preclinical studies to late-stage clinical trials towards potential approval and commercialization, it is common that various aspects of the development program, such as manufacturing methods and formulation, may be altered along the way in an effort to optimize processes and results. Any of these changes could cause our investigational COMP360 drug product or any future drug candidates to perform differently and affect the results of planned clinical trials or other future clinical trials conducted with the materials manufactured using altered processes. Such changes may also require additional testing, FDA notification or FDA approval. This could delay completion of clinical trials, require the conduct of bridging clinical trials or the repetition of one or more clinical trials, increase clinical trial costs, delay approval of COMP360 or any future therapeutic candidates and jeopardize our ability to commence product sales and generate revenue.

Breakthrough Therapy designation by the FDA for COMP360 or any future therapeutic candidates may not lead to a faster development or regulatory review or approval process and it does not increase the likelihood that our investigational COMP360 psilocybin treatment or any future therapeutic candidates will receive marketing approval.

We have received Breakthrough Therapy designation for COMP360 for the treatment of TRD and may seek it for any future therapeutic candidates. 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 existing treatments 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. Drugs designated as breakthrough therapies by the FDA may also be eligible for accelerated approval.

Designation as a breakthrough therapy is within the discretion of the FDA. Accordingly, even if in the future we have therapeutic candidates that we believe meet 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 a Breakthrough Therapy designation for COMP360 and any future therapeutic candidates may not result in a faster development process, review or approval compared to drugs considered for approval under non-expedited FDA review procedures and does not assure ultimate approval by the FDA. In addition, even though COMP360 has been designated as a breakthrough therapy, the FDA may later decide that it, or any future therapeutic candidates that are designated by the FDA as breakthrough therapies, no longer meet the conditions for qualification.

Fast Track designation, if granted by the FDA, may not actually lead to a faster development or regulatory review or approval process.

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We may seek Fast Track designation for any of our therapeutic candidates. If a drug is intended for the treatment of a serious or life-threatening condition and the drug demonstrates the potential to address unmet medical needs for this condition, the drug sponsor may apply for Fast Track designation. The FDA has broad discretion whether or not to grant this designation, so even if we believe a particular therapeutic candidate is eligible for this designation, we cannot assure you that the FDA would decide to grant it. Even if we receive Fast Track designation for any future therapeutic candidates, we may not experience a faster development process, review or approval compared to non-expedited FDA review procedures. In addition, the FDA may withdraw Fast Track designation for any therapeutic candidate that is granted Fast Track designation if it believes that the designation is no longer supported by data from our clinical development program.

We may in the future enter into collaborations for the discovery, development and/or commercialization of additional therapeutic candidates or research programs. Such collaborations may not result in the development of commercially viable therapeutic candidates or the generation of significant future revenue, or we may fail to enter into profitable relationships.

We may enter into collaborations with pharmaceutical companies or others for the discovery, development and/or commercialization of future therapeutic candidates or research programs. For example, we established a Discovery Center under a sponsored research agreement with University of the Sciences Philadelphia (which merged into Saint Joseph’s University in 2022), or USciences. If we fail to enter into or maintain collaborations on reasonable terms, our ability to discover and develop future therapeutic candidates and research programs could be delayed or become more costly. Any future collaborations may subject us to a number of risks, including the following:

•the inability to control the amount and timing of resources that our collaboration partner devotes to our future research programs and therapeutic candidates;

•for collaboration agreements where we may be solely or partially responsible for funding development expenses through a defined milestone event, we may never recoup the costs of these investments if the therapeutic candidate fails to achieve regulatory approval or commercial success;

•we may rely on the information and data received from third parties regarding their research programs and therapeutic candidates without independent verification;

•we may not have control of the process conducted by the third party in gathering and composing data regarding their research programs and therapeutic candidates and we may not have formal or appropriate guarantees with respect to the quality and the completeness of such data;

•we may not have sufficient funds to satisfy any milestone, royalty or other payments we may owe to any third party collaborator;

•our collaboration agreements may contain non-competition provisions which place restrictions on our business operations and the therapeutic candidates and/or indications we may pursue;

•a collaborative partner may develop or commercialize a competing therapeutic candidate either by itself or in collaboration with others, including one or more of our competitors;

•our collaborative partners’ willingness or ability to complete their obligations under our collaboration arrangements may be adversely affected by business combinations or significant changes in a collaborative partner’s strategy;

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•our collaborative partners may experience delays in, or increases in the costs of, the discovery and development of our future therapeutic candidates and research programs and we may be required to pay for any cost increases;

•we may have disagreements with collaborative partners, including disagreements over proprietary rights, selection of lead therapeutic candidates, contract interpretation or the preferred course of development that might cause delays or termination of the research, development or commercialization of therapeutic candidates, might lead to additional responsibilities for us with respect to therapeutic candidates, or might result in litigation or arbitration, any of which would be time-consuming and expensive;

•our collaborative partners may not properly obtain, maintain, defend or enforce intellectual property rights; and

•our collaborative partners may infringe, misappropriate or otherwise violate the intellectual property rights of third parties, which may expose us to litigation and potential liability.

We may face significant competition in seeking appropriate collaborative partners. Our ability to reach a definitive agreement for a collaborative partnership depends, among other things, upon our assessment of a potential collaborator’s resources and expertise, the terms and conditions of the proposed partnership and the potential collaborator’s evaluation of a number of factors. Proposing, negotiating, and implementing collaborations, licensing arrangements, joint ventures, strategic alliances, or partnerships may be a lengthy and complex process. We have limited institutional knowledge and experience with respect to such activities and we may also not realize the anticipated benefits of any such transaction or arrangement.

Should any of the foregoing risks materialize, any collaborations we enter into could fail to result in the development of commercially viable therapeutic candidates or the generation of future revenue, which could have a material adverse effect on our business.

Developing Centers of Excellence, which has in the past and we expect in the future will involve significant costs, time and resources. If our efforts are unsuccessful, our business, prospects and financial condition would be adversely affected.

We have, and may in the future, set up research facilities and innovation labs, which we refer to as Centers of Excellence, in key markets. We announced the establishment of our first Center of Excellence in collaboration with The Sheppard Pratt Institute for Advanced Diagnostics and Therapeutics in Baltimore, Maryland, in January 2021. In March 2022, we announced a strategic collaboration with King’s College London and South London and Maudsley NHS Foundation Trust, or SLaM, to establish The Center for Mental Health Research and Innovation with an overarching goal of accelerating patient access to evidence-based innovation in mental health care by driving forward research in psychedelic treatments through, among other things, the development of working model psychedelic treatment clinics, therapist training programs, conducting clinical trials, and data analysis.

We intend to use these Centers of Excellence to gather evidence to optimize our therapy model, train and certify therapists, conduct clinical trials, including proof of concept studies, develop and test digital technology solutions to improve patient experience and outcomes and pursue other activities to refine our approach to delivering our investigational COMP360 psilocybin treatment safely and cost-effectively. Our efforts to design, build and staff these Centers of Excellence, or identify suitable third parties with whom we may collaborate to open these centers, will involve significant time, costs, including potential capital expenditures to acquire and develop facilities, and other resources, and may divert our management team’s focus from executing on other key elements of our business strategy. If we fail to enter into or maintain agreements with third parties to develop and operate these Centers of Excellence on reasonable terms, or at all, our ability to develop our future research programs and therapeutic candidates could be delayed, the commercial potential of our treatments could change and

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our costs of development and commercialization could increase. If our efforts to develop these Centers of Excellence are unsuccessful, it will have a materially adverse impact on our business, future prospects and financial position.

We may become exposed to costly and damaging liability claims, either when testing our investigational COMP360 psilocybin treatment or any future therapeutic candidates in the clinic or at the commercial stage, and our product liability insurance may not cover all damages from such claims.

We are exposed to potential product liability and professional indemnity risks that are inherent in the research, development, manufacturing, marketing and use of therapeutic substances. Currently, we have no treatments that have been approved for commercial sale; however, the current and future use of our investigational COMP360 psilocybin treatment or any future therapeutic candidates by us and our corporate collaborators in clinical trials, and the potential sale of any approved treatments in the future, may expose us to liability claims. These claims might be made by patients who receive our investigational COMP360 psilocybin treatment in clinical trials and if regulatory approval is obtained, by patients or healthy volunteers who receive it under prescription and by healthcare providers, pharmaceutical companies, our corporate collaborators or other third parties that sell COMP360 psilocybin treatment or any future therapeutic candidates. Any claims against us, regardless of their merit, could be difficult and costly to defend and could materially adversely affect the market for our investigational COMP360 psilocybin treatment or any future therapeutic candidates or any prospects for commercialization of our investigational COMP360 psilocybin treatment or any future therapeutic candidates. Although the clinical trial process is designed to identify and assess potential side effects, it is always possible that a drug, even after regulatory approval, may exhibit unforeseen side effects. If COMP360 or any future therapeutic candidates cause adverse side effects during clinical trials or after regulatory approval, we may be exposed to substantial liabilities. Physicians and patients may not comply with warnings that identify known potential adverse effects and describe which patients should not use COMP360 or any future therapeutic candidates. Regardless of the merits or eventual outcome, liability claims may cause, among other things, the following:

•decreased demand for our treatments due to negative public perception;

•injury to our reputation;

•withdrawal of clinical trial participants or difficulties in recruiting new trial participants;

•initiation of investigations by regulators;

•costs to defend or settle the related litigation;

•a diversion of management’s time and our resources;

•substantial monetary awards to trial participants or patients;

•recalls, withdrawals or labeling, marketing or promotional restrictions;

•loss of revenue from therapeutic sales; and

•the inability to commercialize our investigational COMP360 psilocybin treatment or any future therapeutic candidates, if approved.

It is possible that our liabilities could exceed our insurance coverage. We intend to expand our insurance coverage to include the sale of commercial treatments if we obtain marketing approval for our investigational COMP360 psilocybin treatment or any future therapeutic candidates. However, we may not be able to maintain insurance coverage at a reasonable

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cost or obtain insurance coverage that will be adequate to satisfy any liability that may arise. If a successful product liability claim or series of claims is brought against us for uninsured liabilities or in excess of insured liabilities, our assets may not be sufficient to cover such claims and our business, financial condition and results of operations could be materially adversely affected.

Liability claims resulting from any of the events described above could have a material adverse effect on our business, financial condition and results of operations.

Risks Related to Regulatory Compliance

Psilocybin and psilocin are listed as Schedule I controlled substances under the CSA in the United States, and similar controlled substance legislation in other countries and any significant breaches in our compliance with these laws and regulations, or changes in the laws and regulations, may result in interruptions to our development activity or business continuity.

Psilocybin and psilocin are categorized as Schedule I controlled substances under the CSA, Schedule 1 drugs under the UK’s Misuse of Drugs Regulations 2001 and are similarly categorized by most states and foreign governments. Even assuming that COMP360 or any future therapeutic candidates containing psilocybin or psilocin are approved and scheduled by regulatory authorities to allow their commercial marketing, the ingredients in such therapeutic 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 could have a material adverse effect on us, including on our reputation and ability to conduct business, our financial position, operating results, profitability or liquidity or the market price of our publicly traded ADSs. 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

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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 psilocybin and psilocin does not absolve us of potential liability under U.S. federal law, EU law or English law, 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 psilocybin and psilocin as Schedule I controlled substances in the United States, there may be changes in the status of psilocybin or psilocin under the laws of certain U.S. cities or states. For instance, the city of Denver voted to decriminalize the possession of psilocybin in 2019, and in Oregon, Measure 109 was passed in November 2020 to pave the way for the legal use of “psilocybin products,” including naturally-derived psilocybin substances, in licensed facilities with supervision by licensed facilitators. Oregon psilocybin service centers opened and licensed facilitators began offering psilocybin services to adults over the age of 21 in January 2023. In November 2022, voters in Colorado approved a ballot measure legalizing the use of naturally-derived psilocybin and psilocin in state-regulated centers under the supervision of state-licensed facilitators. Some cities have also passed measures that decriminalizes or minimizes enforcement actions for psilocybin, including, for example, Washington, D.C. (November 2020), Somerville, Massachusetts (January 2021), Cambridge, Massachusetts (February 2021), Northampton, Massachusetts (April 2021), Seattle, Washington (October 2021), San Francisco, California (September 2022), Minneapolis, Minnesota (July 2023) and Portland, Maine (October 2023). The legalization of psilocybin without regulatory oversight or with minimal 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 psilocybin could also impact our commercial sales if we receive regulatory approval as it would reduce the barrier to entry and could increase competition.

We are subject to anti-corruption laws, as well as export control laws, customs laws, sanctions laws and other laws governing our operations. If we fail to comply with these laws, we could be subject to civil or criminal penalties, other remedial measures and legal expenses, be precluded from manufacturing COMP360 and developing and selling our investigational COMP360 psilocybin treatment or any future therapeutic candidates outside the United States or be required to develop and implement costly compliance programs, which could adversely affect our business, results of operations and financial condition.

Our operations are subject to anti-corruption laws, including the UK Bribery Act 2010, or Bribery Act, the U.S. Foreign Corrupt Practices Act, or FCPA, and other anti-corruption laws that apply in countries where we do business and may do business in the future. The Bribery 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 Bribery 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).

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Under the 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 Bribery Act or FCPA violations, and we participate in collaborations and relationships with third parties whose corrupt or illegal activities could potentially subject us to liability under the Bribery Act, FCPA 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, in particular, is expensive and difficult, particularly in countries in which corruption is a recognized problem. In addition, the FCPA presents 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.

We may in the future operate in jurisdictions that pose a high risk of potential Bribery Act or FCPA violations, and we may participate in collaborations and relationships with third parties whose actions could potentially subject us to liability under the Bribery Act, FCPA 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 UK and the U.S., and authorities in the EU, 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 COMP360 and developing and selling our investigational COMP360 psilocybin treatment or any future therapeutic 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 Bribery Act, the FCPA or other legal requirements, including Trade Control laws. If we are not in compliance with the Bribery Act, the FCPA 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 could 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 Bribery Act, the FCPA, other anti-corruption laws or Trade Control laws by UK, U.S. or other authorities could also have an adverse impact on our reputation, our business, results of operations and financial condition.

We may become subject to U.S. federal and state forfeiture laws which could negatively impact our business operations.

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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 psilocybin and psilocin, 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 psilocybin- and psilocin-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 psilocybin and psilocin 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 psilocybin and psilocin 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.

We are subject to certain tax risks and treatments that could negatively impact our results of operations.

Section 280E of the Internal Revenue Code of 1986, as amended, or the Code, prohibits businesses from deducting certain expenses associated with trafficking controlled substances (within the meaning of Schedule I and II of the CSA). The U.S. Internal Revenue Service, or IRS, has invoked Section 280E in tax audits against various businesses in the United States that are permitted under applicable state laws. Although the IRS issued a clarification allowing the deduction of certain expenses, the scope of such items is interpreted very narrowly and the bulk of operating costs and general administrative costs are not permitted to be deducted. There is no guarantee that any federal court will issue an interpretation of Section 280E favorable to psilocybin and psilocin businesses.

We may be unable to use net operating loss and tax credit carryforwards and certain built-in losses to reduce future tax payments or benefit from favorable UK tax legislation.

As a UK incorporated and tax resident entity, we are subject to UK corporate taxation on tax-adjusted trading profits. Due to the nature of our business, we have generated losses since inception and therefore have not paid any UK corporation tax. We had accumulated trading losses for carry forward in the UK of $259.0 million and $176.9 million as of December 31, 2023 and December 31, 2022, respectively. Subject to any relevant utilization criteria and restrictions (including, but not limited to, those that limit the percentage of profits that can be reduced by carried forward losses and 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. The use of loss carryforwards in relation to UK profits incurred on or after April 1, 2017 is limited each year to £5.0 million per group plus, broadly, an incremental 50% of UK taxable profits. In addition, if we were to have a major change in the nature of the conduct of our trade, loss carryforwards may be restricted or extinguished.

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As a company that carries out extensive research and development activities, we seek to benefit from the UK research and development tax relief programs, being the Small and Medium-sized Enterprises R&D tax relief program, or SME Program, and, to the extent that our projects are grant funded or relate to work subcontracted to us by third parties, the Research and Development Expenditure Credit program, or RDEC Program. Under the SME Program, we may be able to surrender the trading losses that arise from our qualifying research and development activities for a cash rebate of an amount up to an effective rate of 18.6% of such qualifying research and development expenditures or carry forward such amount for potential offset against future profits (subject to relevant restrictions). The majority of our research, clinical trials management and manufacturing development activities are eligible for inclusion within these tax credit cash rebate claims. We may not be able to continue to claim payable research and development tax credits in the future if we cease to qualify as a SME, based on size criteria concerning employee staffing levels, turnover and gross assets.

The SME Program incorporates a cap on claims to a multiple of payroll taxes (broadly, to a maximum payable credit equal to £20,000 plus three times the total PAYE and NICs liability of the company) subject to an exception which prevents the cap from applying. That exception requires the company to be creating, taking steps to create or managing intellectual property, as well as having qualifying research and development expenditure in respect of connected parties which does not exceed 15% of the total claimed. If such exception does not apply, this could restrict the amount of payable credit that we claim.

As noted above, the SME R&D tax relief regime has been reduced such that for qualifying expenditure from April 1, 2023 the effective credit decreased from 33.3% to 18.6%. For subcontracted expenditure (paid to unconnected subcontractors), as there is a restriction to 65% of costs, the effective credit decreased from 21.7% to 12.1%. This will impact the level of repayable credit that can be claimed. However, new rules were announced in the Finance Bill 2023-24 for an enhanced rate of relief for R&D intensive companies, which would be 27.0% for qualifying expenditure and 17.5% for qualifying subcontracted expenditure (paid to an unconnected subcontractor). Although these rules will have effect from April 1, 2023, they were not included in Finance (No 2) Act 2003. Instead draft legislation, which is not yet final, was published on July 18, 2023. The Company is therefore unable to determine whether they would meet the criteria for the enhanced rate of relief until the final legislation and more detailed guidance has been published.

Restrictions have also been introduced on relief that may be claimed for expenditure on contracted out research and development activity where the work is undertaken outside the UK, save for very limited exceptions. These changes may impact the quantum of R&D relief that the Company is able to claim in the future and will take effect from April 1, 2024. In addition, the UK government is currently considering merging the SME and RDEC regimes, which may, inter alia, change the present treatment of research and development work and introduce different thresholds and caps on expenditure and relief. The outcome and timing of this merger is still to be confirmed, though draft legislation has been produced, but could have a material impact on the quantum of research and development relief that the Company is able to claim. SME R&D reliefs (whether by way of additional deductions or payable tax credits) are also on a per project basis and each project is limited to a maximum cap of € 7.5 million.

We may benefit in the future from the UK’s “patent box” regime, which allows certain profits attributable to revenue from patented products (and other qualifying income) to be taxed at an effective rate of 10% by giving an additional tax deduction. We own two UK patents which cover our investigational COMP360 psilocybin treatment, and accordingly, future upfront fees, milestone fees, product revenue and royalties could be eligible for this deduction. When taken in combination with the enhanced relief available on our research and development expenditures, we expect a long-term rate of corporation tax lower than the statutory rate to apply to us. If, however, there are unexpected adverse changes to the UK research and development

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tax credit regime or the “patent box” regime, or for any reason we are unable to qualify for such advantageous tax legislation, or we are unable to use net operating loss and tax credit carryforwards 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.

The UK tax authority, His Majesty’s Revenue & Customs, or HMRC, has an increased focus on claims for R&D tax reliefs and so the Company may be subject to increased scrutiny in respect of any claims it makes. In addition, the legislation on the UK R&D tax reliefs regime is updated and changed frequently, so there can be no guarantee of the ability of the Company to make use of reliefs as it might currently expect to in future.

Recently enacted and future legislation may increase the difficulty and cost for us to obtain marketing approval of and commercialize our investigational COMP360 psilocybin treatment or any future therapeutic candidates and could have a material adverse effect on our business.

In the United States, the EU and other foreign jurisdictions, there have been a number of legislative and regulatory changes to the healthcare system that could affect our future results of operations. In particular, there have been and continue to be a number of initiatives at the U.S. federal and state levels that seek to reduce healthcare costs and improve the quality of healthcare. For example, in 2010, the Patient Protection and Affordable Care Act, as amended by the Health Care and Education Reconciliation Act of 2010, or collectively the ACA, substantially changed the way healthcare is financed by both governmental and private insurers, and significantly impacted the U.S. biopharmaceutical industry. For more information regarding the risks related to these laws and regulations, please see the section entitled “Business―Healthcare Reform.”

We expect that changes and challenges to the ACA, as well as other healthcare reform measures that may be adopted in the future, may result in additional reductions in Medicare and other healthcare funding, more rigorous coverage criteria, new payment methodologies, and additional downward pressure on the price that we receive for any future approved product.

New laws and additional health reform measures may result in additional reductions in Medicare and other healthcare funding, which may adversely affect customer demand and affordability for our investigational COMP360 psilocybin treatment and any future therapeutic candidates and, accordingly, the results of our financial operations. These continuing efforts of the government, insurance companies, managed care organizations and other payors of healthcare services to contain or reduce costs of healthcare and/or impose price controls may adversely affect:

•the demand for our investigational COMP360 psilocybin treatment or any future therapeutic candidates, if we obtain regulatory approval;

•our ability to set a price that we believe is fair for our products;

•our ability to obtain coverage and reimbursement approval for a product;

•our ability to generate revenue and achieve or maintain profitability;

•the level of taxes that we are required to pay; and

•the availability of capital.

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We cannot predict what healthcare reform initiatives may be adopted in the future. Further federal and state legislative and regulatory developments are likely, and we expect ongoing initiatives in the U.S. to increase pressure on drug pricing. Such reforms could have an adverse effect on anticipated revenues from one or more of our approved products or other therapeutic candidates that we may successfully develop and for which we may obtain regulatory approval and may affect our overall financial condition and ability to develop therapeutic candidates.

Our business operations and current and future relationships with investigators, health care professionals, consultants, third-party payors and customers may be subject, directly or indirectly, to U.S. federal and state healthcare fraud and abuse laws, false claims laws, health information privacy and security laws, other healthcare laws and regulations and other foreign privacy and security laws. If we are unable to comply, or have not fully complied, with such laws, we could face substantial penalties.

Although we do not currently have any treatments on the market, our current and future operations may be directly, or indirectly through our relationships with investigators, health care professionals, customers and third-party payors, subject to various U.S. federal and state healthcare laws and regulations, including, without limitation, the U.S. federal Anti-Kickback Statute or the federal Anti-Kickback Statute. Healthcare providers, physicians and others play a primary role in the recommendation and prescription of any treatments for which we obtain marketing approval. These laws impact, among other things, our research activities and proposed sales, marketing and education programs and constrain our business and financial arrangements and relationships with third-party payors, healthcare professionals who participate in our clinical research program, healthcare professionals and others who recommend, purchase, or provide our approved treatments, and other parties through which we market, sell and distribute our treatments for which we obtain marketing approval. In addition, we may be subject to patient data privacy and security regulation by both the U.S. federal government and the states in which we conduct our business, along with foreign regulators (including European data protection authorities). Finally, our current and future operations are subject to additional healthcare-related statutory and regulatory requirements and enforcement by foreign regulatory authorities in jurisdictions in which we conduct our business. For more information regarding the risks related to these laws and regulations, please see the section entitled “Business―Other Healthcare Laws and Compliance Requirements.”

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

Further, if any of our Centers for Excellence conduct clinical studies, we may face risks relating to operating a clinical trial site. Such risks may include, but are not limited to, research misconduct and patient injury. In addition, we may end up possessing a large amount of individually identifiable health information. Such activities are subject to a wide variety of laws, such as the Health Insurance Portability and Accountability Act, or HIPAA.

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. Federal and state enforcement bodies have recently increased their scrutiny of interactions between healthcare companies and healthcare providers, which has led to a number of investigations, prosecutions, convictions and settlements in the healthcare industry. Even if precautions are taken, it is possible that governmental authorities will conclude that our business practices may not comply with current or future statutes, regulations or case law involving applicable fraud and abuse or other healthcare laws and regulations. If our operations are found to be in violation of any of these laws or any other governmental regulations that may apply to us, we may be subject to significant civil, criminal and administrative penalties, damages, fines, disgorgement, imprisonment,

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exclusion of drugs from government funded healthcare programs, such as Medicare and Medicaid, additional reporting requirements and oversight if we become subject to a corporate integrity agreement or similar agreement to resolve allegations of non-compliance with these laws, reputational harm and the curtailment or restructuring of our operations. If any of the physicians or other healthcare providers or entities with whom we expect to do business is found not to be in compliance with applicable laws, that person or entity may be subject to significant criminal, civil or administrative sanctions, including exclusions from government funded healthcare programs. Prohibitions or restrictions on sales or withdrawal of future marketed products could materially affect business in an adverse way.

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.

Failure to comply with health and data protection laws and regulations could lead to U.S. federal and state government enforcement actions, including civil or criminal penalties, private litigation, and adverse publicity and could negatively affect our operating results and business.

We and any potential collaborators may be subject to U.S. federal and state data protection laws and regulations, such as 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 information privacy laws, and federal and state consumer protection laws, govern the collection, use, disclosure, 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 the Health Information Technology for Economics and Clinical Health, or HITECH. To the extent that we act as a business associate to a healthcare provider engaging in electronic transactions, 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 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 became enforceable by the California Attorney General on July 1, 2020. The CCPA provides new data privacy rights for consumers (as that term is broadly defined) and new operational requirements for companies, which may increase our compliance costs and potential liability. The CCPA requires covered companies to provide certain disclosures to consumers about its data collection, use and sharing practices, and to provide affected California residents with ways to opt-out of certain sales or transfers of personal information. In particular, 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 for data breaches that has resulted in an increase in data breach litigation. While

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there is currently an exception for protected health information that is subject to HIPAA and clinical trial regulations, as currently written, the CCPA may impact certain of our business activities. There continues to be uncertainty surrounding the enforcement and implementation of the CCPA, exemplifying the vulnerability of our business to the evolving regulatory environment related to personal data and protected health information.

Additionally, a new California ballot initiative, the California Privacy Rights Act, or CPRA, was passed in November 2020. Effective starting on January 1, 2023, the CPRA imposes additional obligations on companies covered by the legislation and will 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 the CPRA. The effects of the CCPA and the CPRA are potentially significant and may require us to modify our data collection or processing practices and policies and to incur substantial costs and expenses in an effort to comply and increase our potential exposure to regulatory enforcement and/or litigation.

The CCPA 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. Certain other state laws impose similar privacy obligations, and we anticipate that more states may enact legislation similar to the CCPA, which provides consumers with new privacy rights and increases the privacy and security obligations of entities handling certain personal information of such consumers. The CCPA has prompted a number of proposals for new federal and state-level privacy legislation. Such proposed legislation, if enacted, may add additional complexity, variation in requirements, restrictions and potential legal risk, require additional investment of resources in compliance programs, impact strategies and the availability of previously useful data and could result in increased compliance costs and/or changes in business practices and policies.

At the federal level, a comprehensive federal data privacy bill, the American Data Privacy and Protection Act, has been proposed and, if passed, will further change the privacy and data security compliance landscape. This proposed legislation, if passed, would help to streamline certain of our privacy obligations, but would also introduce new stringent privacy and data security obligations that would apply to personal data collected from throughout the United States.

Compliance with U.S. and foreign privacy and data protection laws and regulations could require us to take on more onerous obligations in our contracts, restrict our ability to collect, use and disclose data, or in some cases, impact our ability to operate in certain jurisdictions. Failure to comply with these laws and regulations could result in government enforcement actions (which could include civil, criminal and administrative penalties), private litigation, 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.

European data collection is governed by restrictive privacy and security regulations governing the use, processing and cross-border transfer of personal information.

We are subject to European data protection regulations, where we collect and use personal data relating to Europe, including to conduct and enroll subjects in clinical trials in the United Kingdom (UK) or the European Economic Area (EEA). This includes the EU General Data Protection Regulation, or EU GDPR, and the UK equivalent of the same, the UK GDPR (collectively referred to as the GDPR), as well as other national data protection legislation in force in the UK and relevant EEA Member States (including the UK Data Protection Act 2018 in the United Kingdom), which govern the collection, use,

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storage, disclosure, transfer, or other processing of personal data (including health data processed in the context of clinical trials) (i) regarding individuals in the UK and EEA, and/or (ii) carried out in the context of the activities of our establishment in the UK and any EEA Member State.

The GDPR is wide-ranging in scope and imposes numerous additional requirements on companies that process personal data, 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 safeguards are implemented to protect the security and confidentiality of personal data, limiting retention periods for personal data, increasing requirements pertaining to health data and pseudonymized (i.e., key-coded) 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 processors. The GDPR also imposes strict rules on the transfer of personal data to countries outside the UK and EEA, including the United States, and 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 provides individuals with various rights in respect of their personal data, including rights of access, erasure, portability, rectification, restriction and objection. The GDPR also 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 provides that EEA Member States may make their own further laws and regulations in relation to the processing of genetic, biometric or health data, which could result in differences between EEA Member States, limit our ability to use and share personal data or could cause our costs to increase, and harm our business and financial condition.

In addition, we are subject to evolving and strict rules on the transfer of personal data out of the UK and EEA to third countries such as the United States in certain circumstances, unless a derogation exists or a valid GDPR transfer mechanism (for example, the European Commission approved Standard Contractual Clauses, or SCCs, and the UK International Data Transfer Agreement/Addendum, or UK IDTA) have been put in place. Where relying on the SCCs or the UK IDTA for data transfers, we may also be required to carry out transfer impact assessments to assess whether the recipient is subject to local laws which allow public authority access to personal data. Any inability to transfer personal data from the UK and EEA to third countries in compliance with data protection laws may adversely affect our operations and our business and financial position.. If we are investigated by a European data protection authority, we may face fines and other penalties. Any such investigation or charges by European data protection authorities could have a negative effect on our existing business and on our ability to attract and retain new clients or pharmaceutical partners. We may also experience hesitancy, reluctance, or refusal by European or multi-national clients or pharmaceutical partners to continue to use our products due to the potential risk exposure as a result of the current (and, in particular, future) data protection obligations imposed on them by certain data protection authorities in interpretation of current law, including the GDPR. Such clients or pharmaceutical partners may also view any alternative approaches to compliance as being too costly, too burdensome, too legally uncertain, or otherwise objectionable and therefore decide not to do business with us. Any of the foregoing could materially harm our business, prospects, financial condition, and results of operations.

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 the UK and 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,

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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 UK data protection regime is independent from but currently still aligned to the EEA’s data protection regime. However, going forward, there will be increasing scope for divergence in application, interpretation and enforcement of the data protection law as between the United Kingdom and EEA. Although the UK is regarded as a third country under the EU’s GDPR, the European Commission has now issued a decision recognizing the UK as providing adequate protection under the EU GDPR and, therefore, transfers of personal data originating in the EEA to the UK remain unrestricted. The UK government has confirmed that personal data transfers from the UK to the EEA remain free flowing. The UK Government has also now introduced a Data Protection and Digital Information Bill, or Data Reform Bill into the UK legislative process to reform the UK’s data protection regime following Brexit. If passed, the final version of the Data Reform Bill may have the effect of further altering the similarities between the UK and EEA data protection regimes and threaten the UK adequacy decision from the European Commission. The respective provisions and enforcement of the EU GDPR and UK GDPR may further diverge in the future and create additional regulatory challenges and uncertainties. This lack of clarity on future UK laws and regulations and their interaction with EU laws and regulations could add legal risk, complexity and cost to our handling of personal data and our privacy and data security compliance programs and could require us to implement different compliance measures for the UK and the EEA.

The successful commercialization of our investigational COMP360 psilocybin treatment or any future therapeutic candidates will depend in part on the extent to which governmental authorities and health insurers establish adequate reimbursement levels and pricing policies. Failure to obtain or maintain adequate coverage and reimbursement for our investigational COMP360 psilocybin treatment or any future therapeutic candidates, if approved, could limit our ability to market those treatments and decrease our ability to generate revenue.

The availability and adequacy of coverage and reimbursement by governmental healthcare programs such as Medicare and Medicaid, private health insurers and other third-party payors are essential for most patients to be able to afford treatments such as our investigational COMP360 psilocybin treatment or any future therapeutic candidates, if approved. As Schedule I substances under the CSA, psilocybin and psilocin are deemed to have no accepted medical use and treatments that use psilocybin or psilocin are precluded from reimbursement in the United States. Our products must be scheduled as a Schedule II or lower controlled substance (i.e., Schedule III, IV or V) before they can be commercially marketed. Our ability to achieve acceptable levels of coverage and reimbursement for treatments by governmental authorities, private health insurers and other organizations will have an effect on our ability to successfully commercialize, and attract additional collaboration partners to invest in the development of our investigational COMP360 psilocybin treatment or any future therapeutic candidates. There is limited clinical data on the long-term efficacy of psilocybin on treating TRD. Certain patients may need repeated treatments over their lifetime to avoid relapse. This may increase treatment costs, making it more difficult for us to secure reimbursement. Even if we obtain coverage for a given treatment by third-party payors, the resulting reimbursement payment rates may not be adequate or may require patient out-of-pocket costs that patients may find unacceptably high. We cannot be sure that coverage and reimbursement in the United States, Europe or elsewhere will be available for any treatment that we may develop, and any reimbursement that may become available may be decreased or eliminated in the future. For more information regarding the risks related to these laws and regulations, please see the section entitled “Business―Coverage, Pricing and Reimbursement.”

We intend to seek approval to market our investigational COMP360 psilocybin treatment or future therapeutic candidates in both the United States and in selected foreign jurisdictions. If we obtain approval in one or more foreign jurisdictions for COMP360 or our future therapeutic candidates, we will be subject to rules and regulations in those jurisdictions.

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In some foreign countries, particularly certain countries in Europe, the pricing of drugs is subject to governmental control and other market regulations which could put pressure on the pricing and usage of our investigational COMP360 psilocybin treatment or our future therapeutic candidates. In these countries, pricing negotiations with governmental authorities can take considerable time after obtaining marketing approval of a therapeutic candidate. In addition, market acceptance and sales of our investigational COMP360 psilocybin treatment or future therapeutic candidates will depend significantly on the availability of adequate coverage and reimbursement from third-party payors for our investigational COMP360 psilocybin treatment or future therapeutic candidates and may be affected by existing and future healthcare reform measures.

Third-party payors are increasingly challenging prices charged for therapeutic substances and services, and many third-party payors may refuse to provide coverage and reimbursement for particular drugs when an equivalent generic drug or a less expensive drug is available. It is possible that a third-party payor may consider our investigational COMP360 psilocybin treatment or any future therapeutic candidates as substitutable and only offer to reimburse patients for the less expensive drug. Even if we show improved efficacy or improved convenience of administration with our investigational COMP360 psilocybin treatment or any future therapeutic candidates, pricing of existing drugs may limit the amount we will be able to charge. These payors may deny or revoke the reimbursement status of a given drug product or establish prices for new or existing marketed treatments at levels that are too low to enable us to realize an appropriate return on our investment in product development. If reimbursement is not available or is available only at limited levels, we may not be able to successfully commercialize our investigational COMP360 psilocybin treatment or any future therapeutic candidates, and may not be able to obtain a satisfactory financial return on therapeutic candidates that we may develop.

There is significant uncertainty related to the insurance coverage and reimbursement of newly approved treatments. In the United States, third-party payors, including private and governmental payors, such as the Medicare and Medicaid programs, play an important role in determining the extent to which new drugs will be covered. The Medicare and Medicaid programs increasingly are used as models for how private payors and other governmental payors develop their coverage and reimbursement policies for drugs. Some third-party payors may require pre-approval of coverage for new or innovative devices or drug products before they will reimburse health care providers who use such treatments. It is difficult to predict at this time what third-party payors will decide with respect to the coverage and reimbursement for our investigational COMP360 psilocybin treatment or any future therapeutic candidates.

Obtaining and maintaining reimbursement status is time-consuming and costly. No uniform policy for coverage and reimbursement for drug products exists among third-party payors in the United States. Therefore, coverage and reimbursement for drug products can differ significantly from payor to payor. As a result, the coverage determination process is often a time-consuming and costly process that will require us to provide scientific and clinical support for the use of our treatments to each payor separately, with no assurance that coverage and adequate reimbursement will be applied consistently or obtained in the first instance. Furthermore, rules and regulations regarding reimbursement change frequently, in some cases at short notice, and we believe that changes in these rules and regulations are likely.

On the state level, local governments have been very aggressive in passing legislation and implementing regulations designed to control pharmaceutical 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 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

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could reduce the ultimate demand for our treatments or put pressure on our therapeutic pricing, which could negatively affect our business, results of operations, financial condition and prospects.

Outside the United States, international operations are generally subject to extensive governmental price controls and other market regulations, and we believe the increasing emphasis on cost-containment initiatives in Europe, and other countries has and will continue to put pressure on the pricing and usage of our investigational COMP360 psilocybin treatment or any future therapeutic candidates. In many countries, the prices of medical treatments are subject to varying price control mechanisms as part of national health systems. Other countries allow companies to fix their own prices for medical treatments, but monitor and control company profits. Additional foreign price controls or other changes in pricing regulation could restrict the amount that we are able to charge for our investigational COMP360 psilocybin treatment or any future therapeutic candidates. Accordingly, in markets outside the United States, the reimbursement for our treatments may be reduced compared with the United States and may be insufficient to generate commercially reasonable revenue and profits.

The delivery of healthcare in the EU, 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-wide, law and policy. National governments and health service providers have different priorities and approaches to the delivery of healthcare and the pricing and reimbursement of treatments in that context. In general, however, the healthcare budgetary constraints in many EU Member States have resulted in restrictions on the pricing and reimbursement of medicines by relevant health service providers. Coupled with increasing EU and national regulatory burdens on those wishing to develop and market treatments, this could prevent or delay marketing approval of our investigational COMP360 psilocybin treatment or any future therapeutic candidates, restrict or regulate post-approval activities and affect our ability to commercialize any treatments for which we obtain marketing approval.

EU drug marketing regulation may materially affect our ability to market and receive coverage for our treatments in the EU Member States. 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 treatments is also prohibited in most countries within the EU. The provision of benefits or advantages to induce or reward improper performance generally is typically governed by the national anti-bribery laws of EU Member States, and in respect of the UK, the Bribery Act 2010. Infringement of these laws could result in substantial fines and imprisonment. EU Directive 2001/83/EC, which is the EU Directive governing medicinal products for human use, further provides that, where medicinal products are being promoted to persons qualified to prescribe or supply them, no gifts, pecuniary advantages or benefits in kind may be supplied, offered or promised to such persons unless they are inexpensive and relevant to the practice of medicine or pharmacy. This provision has been transposed into the Human Medicines Regulations 2012 and so remains applicable in the UK despite its departure from the EU.

Payments made to physicians and other healthcare professionals 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 individual EU Member States and the particular requirements can therefore vary widely amongst 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 many EU Member States, 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

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country to country. For example, individual Member States in the EU have the ability 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 our investigational COMP360 psilocybin treatment or any of our future therapeutic candidates to other available treatments 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 treatments. Historically, drug products launched in the EU 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 treatments is unavailable or limited in scope or amount, our revenue from sales and the potential profitability of our investigational COMP360 psilocybin treatment or any of our future therapeutic candidates in those countries would be negatively affected.

Moreover, increasing efforts by governmental and third-party payors in the EU, the United States and elsewhere to cap or reduce healthcare costs may cause such organizations to limit coverage and the level of reimbursement for newly approved treatments and, as a result, they may not cover or provide adequate payment for our investigational COMP360 psilocybin treatment or any future therapeutic candidates. In international markets, reimbursement and healthcare payment systems vary significantly by country, and many countries have instituted price ceilings on specific treatments. We expect to experience pricing pressures in connection with the sale of our investigational COMP360 psilocybin treatment or any future therapeutic candidates due to the trend toward managed healthcare, the increasing influence of health maintenance organizations and additional legislative changes. The downward pressure on healthcare costs in general, particularly prescription drugs and surgical procedures and other treatments, has become very intense. As a result, increasingly high barriers are being erected to the entry of new treatments.

We could experience difficulty enforcing our contracts.

Due to the nature of our business and the fact that some of our contracts involve psychedelics including psilocybin and psilocin, the use of which is not legal under U.S. federal law and in certain other jurisdictions, we may face difficulties in enforcing our contracts in U.S. federal and state courts. The inability to enforce any of our contracts could have a material adverse effect on our business, operating results, financial condition or prospects.

In order to manage our contracts with contractors, we ensure that such contractors are appropriately licensed at the state and federal level in the United States, and at the appropriate level in other territories. Were such contractors to operate outside the terms of these licenses, we may experience an adverse effect on our business, including the pace of development of our investigational COMP360 psilocybin treatment or any future psychedelic-based drug candidate.

Risks Related to Intellectual Property

We rely on patents and other intellectual property rights to protect our investigational COMP360 psilocybin treatment, the enforcement, defense and maintenance of which may be challenging and costly. Failure to enforce or protect these rights adequately could harm our ability to compete and impair our business.

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Our commercial success depends in part on obtaining and maintaining patents and other forms of intellectual property rights for COMP360, any future therapeutic candidates and associated psychological support, digital tools, methods used to manufacture the underlying drug substances, and the methods for treating patients using those substances, or on licensing in such rights. 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 our investigational COMP360 psilocybin treatment and any future therapeutic 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 adversely affect our operations and prospects.

We cannot be certain that patents will be issued or granted with respect to patent applications that are currently pending, 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. 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 treatments. As such, we do not know the degree of future protection that we will have on our proprietary treatments.

The patent prosecution process is expensive, complex and time-consuming, and we and our current or future third party partners, 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 the 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 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.

Further, the issuance, scope, validity, enforceability and commercial value of our and our current or future licensors’, licensees’ or collaboration partners’ patent rights are highly uncertain. Our and our licensors’ pending and future patent applications may not result in patents being issued that protect our treatments, in whole or in part, or that effectively prevent others from commercializing competitive technologies and treatments.

Moreover, in some circumstances, we may not have the right to control the preparation, filing and prosecution of patent applications, or to maintain the patents, covering technology that we license from or license to third parties and are reliant on our licensors, licensees or collaboration partners. If our current or future licensors, licensees or collaboration partners fail to

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establish, maintain or protect such patents and other intellectual property rights, such rights may be reduced or eliminated. If our licensors, licensees or collaboration partners are not fully cooperative or disagree with us as to the prosecution, maintenance or enforcement of any patent rights, such patent rights could be compromised.

The patent examination process may 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 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 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 COMP360 and any future therapeutic 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 the patent claims being narrowed or invalidated. For example, in December 2021, a third party filed two petitions requesting post grant review of two of our patents (U.S. Patent 10,947,257 and U.S. Patent 10,954,259) before the Patent Trial & Appeal Board of the U.S. Patent and Trademark Office, or the USPTO Board. On June 22, 2022, the USPTO Board issued decisions in both cases denying institution of post grant review on the merits of the arguments presented in each of the challenges. On July 22, 2022, the third-party challenger filed a request with the USPTO Board for rehearing of the USPTO Board’s decision, as well as a request for Precedential Opinion Panel on August 16, 2022 in each of the challenges. On February 10, 2023, the USPTO Board denied the request for Precedential Opinion Panel in each of the challenges. On May 23, 2023, the USPTO Board denied the requests for rehearing in each of the challenges. We cannot provide any assurances that we will successfully defend ourselves against any future patent challenges.

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 also will not protect our technology, COMP360 and any future therapeutic candidates if third parties, including our competitors, design around our protected technology and our investigational COMP360 psilocybin treatment and any future therapeutic candidates without infringing, misappropriating or otherwise violating our patents or other intellectual property rights. Moreover, some of our patents and patent applications may in the future be co-owned with third parties. 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 treatments 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 current or future licensors, licensees or collaborators were or will be the first to file any patent application related to a therapeutic 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 at the USPTO 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 at

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the USPTO 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 treatments and technology. Any of the foregoing could have a material adverse effect on our competitive position, business, financial condition, results of operations, and prospects.

Issued patents covering one or more of our investigational therapeutics could be found invalid or unenforceable if challenged in court.

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 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 UK, EU and the United States. We may fail in enforcing our rights, in which case our competitors and other third parties may be permitted to use our treatments 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 treatments, 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 investigational treatments, 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. A claim for unenforceability assertion could be an allegation that someone connected with prosecution of the patent withheld relevant information from 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 COMP360 or any future therapeutic candidates. For example, on July 22, 2022, a third-party challenger filed with the USPTO Board requests for rehearing of the USPTO Board’s decisions to deny institution of post-grant reviews of U.S. Patent 10,947,257 and U.S. Patent 10,954,259, and on August 16, 2022, the third-party challenger also filed requests for a Precedential Opinion Panel in each of the patents. On February 10, 2023, the USPTO Board denied the request for a Precedential Opinion Panel in each of the challenges. On May 23, 2023, the USPTO Board denied the requests for rehearing in each of the challenges. 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

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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 COMP360 or one or more of any future therapeutic 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.

Obtaining and maintaining our patent protection depends on compliance with various procedural, document submission, fee payment and other requirements imposed by governmental patent agencies, and our patent protection could be reduced or eliminated for non-compliance with these requirements.

Periodic maintenance and annuity fees on any issued patent are due to be paid to the European Patent Office, the USPTO and foreign patent agencies in several stages over the lifetime of the 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 rely on our collaboration partners to pay these fees due to the United States and comparable foreign patent agencies and take the necessary action to comply with such requirements with respect to our intellectual property. While an inadvertent lapse 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 noncompliance can result in abandonment or lapse of the patent or patent application, resulting in 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 licensors or collaboration partners fail to maintain the patents and patent applications covering our investigational treatments, third parties, including our competitors might be able to enter the market with similar or identical treatments or technologies, which would have a material adverse effect on our business, financial condition, results of operations, and prospects.

If we do not obtain protection under the Hatch-Waxman Amendments and similar foreign legislation for extending the term of patents covering each of our investigational treatments, our business may be materially harmed.

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 non-provisional filing date. Various extensions may be available, but the life of a patent, and the protection it affords, is limited. Even if patents covering our investigational treatments, their manufacture, or use are obtained, once the patent life has expired, we may be open to competition from competitive treatments. Given the amount of time required for the development, testing and regulatory review of new investigational treatments, patents protecting such candidates and concomitant treatments might expire before or shortly after such candidates and concomitant treatments are commercialized. As a result, our owned and licensed patent portfolio may not provide us with sufficient rights to exclude others from commercializing treatments similar or identical to ours.

Depending upon the timing, duration and conditions of FDA marketing approval of COMP360 and any future therapeutic candidates, one or more of our U.S. patents may be eligible for limited patent term extension under the Drug Price Competition and Patent Term Restoration Act of 1984, or the Hatch-Waxman Act, and similar legislation in the EU. The Hatch-Waxman Act permits a patent term extension of up to five years for a patent covering an approved product as compensation for effective patent term loss during product development, the FDA regulatory review process and the issuance of a final decision controlling the product under the Controlled Substance Act. The patent term extension cannot extend the remaining term of a patent beyond a total of 14 years from the date of product approval, only one patent 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.

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However, we may not receive an extension because of, for example, 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 treatments sooner than we expect. As a result, our revenue from applicable treatments could be materially reduced and our business, financial condition, results of operations, and prospects could be materially harmed.

Intellectual property rights do not necessarily address all potential threats to our competitive advantage.

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. The following examples are illustrative:

•others may be able to make compounds or develop digital assets that are the same as or similar to our investigational COMP360 psilocybin treatment, any future therapeutic candidates and digital assets but that are not covered by the claims of the patents that we own or control;

•the patents of third parties may have an adverse effect on our business;

•we or our licensors or any current or future collaboration partners might not have been the first to conceive or reduce to practice the inventions covered by the issued patent or pending patent application that we own or control;

•we or our licensors or any current or future collaboration partners might not have been the first to file patent applications covering certain of our inventions;

•others may independently develop similar or alternative technologies or duplicate any of our technologies without infringing, misappropriating or otherwise violating our intellectual property rights;

•it is possible that our current and future pending patent applications will not lead to issued patents;

•issued patents that we own or have exclusively licensed may not provide us with any competitive advantage, or may be held invalid or unenforceable, as a result of legal challenges by third parties;

•our competitors might conduct research and development activities in countries where we do not have patent rights and then use the information learned from such activities to develop competitive treatments for sale in our major commercial markets;

•third parties performing manufacturing or testing for us using our treatments or technologies could unknowingly use the intellectual property of others without obtaining a proper license;

•we may not develop additional technologies that are patentable; and

•we may choose not to file a patent in order to maintain certain trade secrets or know-how, and a third party may subsequently file a patent covering such intellectual property, or otherwise develop similar know-how.

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

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We may be subject to claims by third parties asserting that our employees or we have misappropriated their intellectual property, or claiming ownership of what we regard as our own intellectual property.

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.

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. Such intellectual property rights could be awarded to a third party, and we could be required to obtain a license from such third party to commercialize our treatments. 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.

In addition, 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. The assignment of intellectual property rights may not be self-executing, or the assignment agreements may be breached, 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.

Intellectual property rights of third parties could adversely affect our ability to compete or commercialize our investigational treatments, such that we could be required to litigate or obtain licenses from third parties in order to develop or market our investigational treatments. Such litigation or licenses could be costly or not available on commercially reasonable terms.

Our commercial success depends upon our ability and the ability of our future collaborators to develop, manufacture, market, and sell any investigational treatments 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 past, we have been subject to, and in the future we may become party to, or threatened with, adversarial proceedings or litigation regarding intellectual property rights with respect to COMP360 or any future therapeutic 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 treatments or elements thereof, our manufacture or uses relevant to our development plans, the targets of COMP360 or any future therapeutic candidates, or other attributes of our investigational COMP360 psilocybin treatment or any future therapeutic candidates. In such cases, we may not be in a position to develop or commercialize such therapeutic 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 investigational treatments or

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therapeutic candidate and the patent owner were to bring an infringement action against us, we may have to argue that our investigational treatments 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 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 investigational treatments, unless we obtain a license to such patent, which may not be available on commercially reasonable terms or at all, we could be prevented from continuing to develop or commercialize our investigational treatments. Similarly, the targets for our investigational COMP360 psilocybin treatment have also been the subject of research by other companies, which have filed patent applications or have patents on aspects of the targets or their uses. There can be no assurance any such patents will not be asserted against us or that we will not need to seek licenses from such third parties. We may not be able to secure such licenses on acceptable terms, or at all, and any such litigation would be costly and time-consuming.

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. 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 treatments 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 treatments or the use of our treatments.

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 treatments.

If we are unsuccessful defending in 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 investigational treatments that were held to be infringing. If possible, we might be forced to redesign our investigational COMP360 psilocybin treatment or any future therapeutic 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. 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

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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 investigational treatments. 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.

Intellectual property litigation could cause us to spend substantial resources, distract our personnel from their normal responsibilities, harming our reputation and our business operations.

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, there could 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 ADSs. 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 proceedings could have a material adverse effect on our ability to compete in the marketplace.

We may not be successful in obtaining or maintaining necessary rights to COMP360 or any future therapeutic candidates through acquisitions and in-licenses.

In the future, our programs may require the use of 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 or use these proprietary rights. In addition, with respect to any patents we 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 COMP360 or any future therapeutic candidates. 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 obtain a license to third-party intellectual property rights necessary for the development of an investigational treatment or program, we may have to abandon development of that investigational treatment or program, which could have a material adverse effect on our business, financial condition, results of operations, and prospects.

For example, we sometimes collaborate with U.S. and foreign academic institutions to accelerate our preclinical 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,

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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 treatment or program.

If we fail to comply with our obligations under the agreements pursuant to which we license intellectual property rights to or from third parties, or otherwise experience disruptions to our business relationships with our licensors, licensees or collaborators, we could lose the rights to intellectual property that are important to our business.

We are or may become a party to third-party agreements under which we grant or are granted rights to intellectual property that are potentially important to our business and we expect that we may need to enter into additional license or collaboration agreements in the future. Our existing third-party agreements impose, and we expect that future license agreements will impose, various obligations related to, among other things, therapeutic development and payment of royalties and fees based on achieving certain milestones. In addition, under several of our collaboration agreements, we are prohibited from developing and commercializing treatments that would compete with the treatments 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.

The termination of any license or collaboration agreements or failure to adequately protect such license agreements or collaboration could prevent us from commercializing our investigational COMP360 psilocybin treatment or any future therapeutic candidates covered by the agreement or licensed intellectual property. 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 treatments. If this agreement were to terminate, we would 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 our investigational COMP360 psilocybin treatment or any future therapeutic candidates, which could delay or otherwise have a material adverse effect on the development and commercialization of our investigational COMP360 psilocybin treatment or any future therapeutic candidates.

Several of our existing license agreements are 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 the 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 it 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 our investigational COMP360 psilocybin treatment or any future therapeutic candidates incorporating the relevant intellectual property.

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

•the scope of rights granted under the agreement and other interpretation-related issues;

•the extent to which our technology and processes infringe on intellectual property of the licensor or collaboration partner that is not subject to the agreement;

•the sublicensing of patent and other rights under any current or future collaboration relationships;

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