Compass reports one-year COMP360 psilocybin data and keeps its FDA filing on track for late 2026

What Compass reported in September

The new figures come from Part C of COMP005, an open-label extension in which participants could receive another session. About 70% of participants entered Part C. Among people first assigned to the active arm who took another dose (n = 90), scores on the MADRS depression scale were an average of 13 points below their original baseline at week 52.¹ Across everyone who received COMP360 in Part C, including 52 people first assigned to placebo, between 40% and 45% met the response definition (at least a 50% fall in MADRS score), and about 30% met the remission definition, at time points in the 6 weeks after the Part C session.¹

Part C was open-label with no control group, so these numbers describe people who entered the extension, not a comparison with placebo.

The two Phase 3 trials behind the filing

COMP005 gave 258 people either one 25 mg administration of COMP360 (171 people) or placebo (87). At week 6 the active arm's MADRS score had fallen 3.6 points more than placebo's (95% CI -5.7 to -1.5; p<0.001), and 25% of the active arm had at least a 25% fall in MADRS score.²

COMP006, the larger trial, gave participants two fixed administrations three weeks apart of 25 mg, 10 mg or 1 mg COMP360 (581 dosed: 296, 142 and 143), called the high, middle and low arms here. At week 6, reported February 17, 2026, the high arm's MADRS score had fallen 3.8 points more than the low arm's (95% CI -5.8 to -1.8; p<0.001), and 39% of the high arm had at least a 25% fall in MADRS score.² At 26 weeks, reported July 7, the gap between the two arms held, nearly 30% of the people with that 25% fall at week 6 later reached remission after retreatment, and serious adverse events were 6.3% in the low arm and 5.7% in the high arm.³ Neither release reports results for the middle arm.

The filing and the timeline

On April 24, 2026, FDA issued national priority vouchers to three companies studying psilocybin for treatment-resistant depression, psilocybin for major depressive disorder and methylone for PTSD, without naming them.⁴ Compass confirmed it holds one, along with an FDA-granted rolling review, and cites a "1-2 month review time following filing".⁵ Managed Healthcare Executive reported Usona and Transcend as the other two recipients; FDA's release doesn't confirm that.⁶

Compass says the final submission is "on track to be completed in Q4".¹ Psilocybin is a Schedule I controlled substance under federal law. Executive Order 14401 of April 18, 2026 directs the Attorney General to review for rescheduling any product containing a Schedule I substance that completes Phase 3 trials for a serious mental health disorder.⁷

Other trials with results pending

Usona Institute's Phase 3 trial in major depressive disorder (NCT06308653, 238 enrolled, with a placebo arm) reached primary completion on January 5, 2026, with no results posted as of the registry's October 21, 2026 update.⁸ Cybin, presenting as Helus Pharma, completed primary data collection in its APPROACH trial of a deuterated psilocin analog on September 4, 2026.⁹

Why it matters for dose claims

If approved, COMP360 would be a fixed, labeled amount of one synthetic compound, given in a supervised setting to screened patients. The results describe that product, not mushrooms of unknown potency. Both trials gave everyone in an arm the same amount regardless of body weight; our guide on body weight and psilocybin explains why trials moved to fixed amounts, and our page on who trials exclude lists the usual screening criteria.

The unpublished middle arm is the clearest gap in the public dose-response picture. FDA's final guidance on psychedelic trials, issued in July 2026, says sponsors "should plan to characterize the dose-response relationship for both safety and efficacy early in the drug development program".¹⁰