A New Frontier in Mental Health

On 06 December 2024, COMPASS Pathways announced that the U.S. Food and Drug Administration (FDA) has granted clearance to initiate a Phase III trial of psilocybin-assisted therapy for post-traumatic stress disorder (PTSD). This marks the first time a psychedelic compound has reached late-stage testing for PTSD, a condition affecting over 12 million Americans annually.

The study will evaluate COMP360, a synthetic formulation of psilocybin, in combination with psychological support. Previous Phase II data showed significant reductions in PTSD symptom severity, with effects sustained for up to 12 weeks post-treatment.

Trial Design and Objectives

The Phase III trial will enroll approximately 600 participants across North America and Europe. Key features include:

• A single-dose psilocybin session with trained therapists
• Primary endpoint: change in CAPS-5 scores (Clinician-Administered PTSD Scale)
• Secondary endpoints: functional improvement, quality of life, and durability of response

The trial will also include a placebo-controlled arm and long-term follow-up to assess relapse rates and safety.

Regulatory and Industry Implications

The FDA’s decision reflects growing confidence in the therapeutic potential of psychedelics, following recent approvals for MDMA-assisted therapy in PTSD and expanded access programs for psilocybin in depression.

If successful, COMP360 could become the first psychedelic-based treatment approved for PTSD, potentially reshaping psychiatric care and expanding options for patients unresponsive to conventional therapies.

COMPASS Pathways is also exploring psilocybin’s use in anorexia nervosa and bipolar depression, signaling a broader push into neuropsychiatric indications.