COMPASS Pathways plc

Hercules Loan Agreement Amendment

On July 30, 2025, we entered into the second amendment to our Loan and Security Agreement, as amended, or the Second Amendment, with Hercules, pursuant to which (i) the additional term loan of up to $10.0 million, which was available until June 30 2025, under the second tranche was removed and (ii) the additional term loan under the third tranche, which is subject to the approval of Hercules’ investment committee in its sole discretion, and only available during the interest-only period, was increased by $10.0 million, to an aggregate of $20.0 million. The description of the Second Amendment contained herein does not purport to be complete and is qualified in its entirety by reference to the complete text of the Second Amendment, a copy of which is filed as Exhibit 10.2 to this Quarterly Report on Form 10-Q and is incorporated herein by reference.

COMP401 Study

Our double-blind randomized controlled Phase 2 clinical trial investigating the safety and efficacy of COMP360 psilocybin in participants with anorexia nervosa completed. It was a multicenter study, which enrolled 32 participants, evaluating COMP360 dosed at 25mg against a control arm of participants receiving COMP360 1mg. There was an encouraging positive signal of improvement in eating disorder symptom score sustained through 12 weeks in the 25mg arm, but the low overall numbers of participants and high number of dropouts in the control arm (only 6 of the 11 participants in the control arm completed the study) limited the statistical power of the study. The safety profile was aligned with the high-risk patient population of anorexia nervosa and no unexpected safety signals were reported. There was no clinically meaningful imbalance in suicidal ideation across arms. We plan to present the full results at a future medical meeting.

Rule 10b5-1 Trading Plans

During the three months ended June 30, 2025, none of our directors or executive officers adopted, modified, orterminated a “Rule 10b5-1 trading arrangement” or a “non-Rule 10b5-1 trading arrangement” as such terms are defined in Item 408(a) of Regulation S-K.