FDA Accepts Investigational New Drug Application for COMP360 for PTSD

The US Food and Drug Administration has accepted the Investigational New Drug Application for COMP360 in the treatment of patients with posttraumatic stress disorder, according to a press statement from Compass Pathways.¹

The acceptance allows the company to initiate a phase 2b/3 clinical trial with patients with PTSD. The multicenter, randomized double blind controlled study will be comprised of a blinded arm and an open label arm and will investigate the efficacy, safety, and tolerability of the agent in patients with PTSD. The blinded arm will be 12-weeks in duration and will be the double-blinded and controlled portion of the study. It will assess the efficacy of 2 administrations of 25 mg versus 2 doses of 1 mg of COMP360, with the second administrations scheduled for approximately 4 weeks after the first. Investigators will look at the change in Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) total severity score at week 8 as the primary efficacy endpoint.¹

The 40-week open label follow up trial is the second part of the study. It will look at the long-term safety and efficacy of the treatment administered in part A. Those patients enrolled in the Part B part of the study will receive one open label treatment of COMP360 25 mg.

Participants in both arms may receive COMP360 as an adjunctive to a single oral antidepressant.

The previous multicenter phase 2 study (NCT05312151) was open label and included 22 patients with severe PTSD. In the study, participants received one 25 mg COMP360 dose as well as psychological support. The study met its primary safety and secondary efficacy points. Specifically, the study demonstrated 9.9 and 29.5 point reductions from CAPS-5 total score at week 4 and 12, respectively. Similarly, the study found 11.7 and 14.4 point reductions in Sheehan Disability Scale total scores at week 4 and 12, respectively.²

In terms of safety, there were no treatment-emergent serious adverse events. Most commonly reported adverse events were headache 50%); nausea (36.4%), crying (27.3%), and fatigue (27.3%). Although suicidal ideation was reported in 2 patients with a history of suicidality, both were resolved during the study, with the first case resolving on the day of administration.²

COMP360 is an investigational synthetic psilocybin treatment with the potential for being a first in class treatment. It received breakthrough therapy designation by the FDA for the treatment-resistant depression (TRD). Data from their phase 3 trials COMP006 and COMP005 for TRD are expected early in the first and third quarters of 2026, respectively.¹

Compass Pathways is excited about what the future holds and is dedicated to advancing psychiatric care. In a statement to the press, chief executive officer Kabir Nath said, “We enter 2026 with excitement and strong momentum, driving innovation to address critical needs in both PTSD and TRD…We look forward to continuing our close collaboration with the FDA and remain committed to generating robust clinical evidence with scientific rigor as we move into this next chapter.”¹

“We are pleased to advance our clinical development - the unmet need is profound, and it demands bold innovation,” Guy Goodwin, FMedSci, DPhil, chief medical officer of Compass Pathways and emeritus professor of psychiatry at The University of Oxford, said in a press statement. “We believe COMP360 has the potential to transform the treatment landscape for PTSD and bring hope to those who need it most.”¹

The company plans to hold a webinar later this morning with more information. The session will include expert speakers like Gary Small, MD, director of of Behavioral Health Therapies, Hackensack Meridian Health, and Geoffery Grammer, MD, CMO at Greenbrook Mental Wellness Centers.

References

1. Compass Pathways Announces FDA Acceptance of IND Application for PTSD and Hosts Webinar on PTSD and TRD. Press release. Business Wire. January 7, 2026. Accessed January 7, 2026. https://www.businesswire.com/news/home/20260107267454/en/Compass-Pathways-Announces-FDA-Acceptance-of-IND-Application-for-PTSD-and-Hosts-Webinar-on-PTSD-and-TRD

2. Duerr HA. Phase 2 Study of COMP360 Psilocybin Finds Improved PTSD Symptoms. Psychiatric Times. May 9, 2024. Accessed January 7, 2026. https://www.psychiatrictimes.com/view/phase2-study-of-comp360-psilocybin-finds-improved-ptsd-symptoms