COMPASS Pathways : Presentation – November 2022

Transforming Mental Health Care

NOVEMBER 2022

Disclaimer

Cautionary Note Regarding Forward-LookingStatements This presentation includes "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995, as amended. In some cases, you can identify forward-looking statements by terms such as "believe," "continue," "could," "estimate," "expect," "may," "might," "plan," "potential," "project," "should," "target," "will," "would," or the negative of these terms, and similar expressions intended to identify forward-looking statements. However, not all forward-looking statements contain these identifying words. These forward-looking statements include express or implied statements relating to our strategic plans or objectives, our plans and expected timing for our phase III program in treatment resistant depression and the potential for that or other trials to support regulatory filings and approvals, the future accessibility of COMP360 psilocybin therapy, our ability to launch and successfully commercialize COMP360 psilocybin therapy, potential revenue streams if COMP360 psilocybin therapy is approved and our ability to advance COMP360 psilocybin therapy in other areas of high unmet mental health need and to discover and advance new drug compounds. By their nature, these statements are subject to numerous risk and uncertainties, including factors beyond our control, that could cause actual results, performance or achievement to differ materially and adversely from those anticipated or implied in the statements. For additional disclosure regarding these and other risks faced by the Company, see the disclosure contained under the heading "Risk Factors" and elsewhere in the Company's public filings with the US Securities and Exchange Commission (the "SEC"). You should not rely upon forward- looking statements as predictions of future events. Although our management believes that the expectations reflected in our statements are reasonable, we cannot guarantee that the future results, levels of activity, performance or events and circumstances described in the forward-looking statements will be achieved or occur. Moreover, neither we, nor any other person, assumes responsibility for the accuracy and completeness of these statements. Accordingly, you are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date such statements are made and should not be construed as statements of fact. Except as required by applicable law, we undertake no obligation to update these forward-looking statements to reflect any new information, events or circumstances after the date hereof, or to reflect the occurrence of unanticipated events. No representations or warranties (expressed or implied) are made about the accuracy of any such forward-looking statements.

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We're a mental health care company.

We're committed to developing innovative, evidence-based therapies that

help patients and their families, and ease the burden on our overstretched healthcare systems.

3 | © COMPASS Pathways plc 2022

COMP360 psilocybin therapy includes three elements

COMP360 psilocybin therapy

COMP360 psilocybin

Psychological support

Digital tools

Our synthetic, high-purity polymorphic crystalline formulation of psilocybin, a psychoactive compound.

Psychological support from registered and trained mental health professionals.

.

A patient app, therapist portal and AI-driven analytics platform enhancing patient experience and outcomes.

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Phase 2b trial: Results demonstrate the potential for a rapid, sustained response in TRD

In a randomized, controlled, double- blind trial, three groups of participants were given a single dose (either 1mg, 10mg or 25 mg) of COMP360 psilocybin alongside psychological support.

Results were measured as a change on the MADRS depression scale from baseline (a day prior to administration) over a 12-week period.

Primary efficacy assessment,		Follow-up period,
3 weeks post administration		3-12 weeks post administration

1 mg

10 mg

25 mg

Difference vs 1 mg at Week 3

• 25 mg: -6.6 (95% confidence interval: -10.2 ; -2.9),p<0.001
• 10 mg: -2.5, p=0.184

The primary endpoint of this study was the change from baseline in MADRS total score at week 3.

Efficacy: We saw a

statistically significant and clinically meaningful reduction in depression symptoms.

Rapid onset of action: The effect occurred the day after the administration.

Durability: We saw a sustained response at week 12 - a positive indication for high potential as a monotherapy.

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NOTE: *Least square mean change from baseline in MADRS total score; MADRS = Montgomery-Åsberg Depression Rating Scale