A phase 3 trial of COMP360, a synthetic psilocybin formulation, shows durable benefits lasting at least 6 months in patients with treatment-resistant depression. The 25mg dose significantly reduced symptom severity, with 39% of responders maintaining improvement through week 26. Compass Pathways plans to file a New Drug Application by Q4 2026.
Compass Pathways has released six-month data from its phase 3 COMP006 trial, showing that COMP360 — a synthetic, proprietary psilocybin formulation — delivers rapid and durable benefits for patients with treatment-resistant depression (TRD). The randomized, double-blind study tested two fixed doses (25mg and 10mg) given three weeks apart against a 1mg control in adults with TRD, tracking outcomes over 52 weeks.
The 25mg dose stood out: it significantly reduced depression severity on the MADRS scale at week 6, and that separation from the control group held steady through week 26. After retreatment, nearly 30% of initial responders went on to achieve full remission. Results were consistent with a separate phase 3 trial (COMP005), strengthening confidence in the drug's profile. Side effects — mainly nausea, headache, anxiety, and visual hallucinations — were largely limited to dosing days.
Key Takeaways:
Why it matters: TRD affects millions of patients who don't respond to standard antidepressants, leaving them with few options. If approved, COMP360 could become the first synthetic psilocybin therapy on the market for this population — a significant milestone in psychedelic-assisted psychiatry.
