Compass Pathways reports positive phase 3 results for psilocybin therapy

Tuesday 17 - 14:20

By: Dakir Madiha

Compass Pathways reports positive phase 3 results for psilocybin therapy

Compass Pathways said its experimental psilocybin-based treatment, COMP360, met the primary endpoint in its second pivotal phase 3 trial for treatment-resistant depression, moving the company closer to what could become the first US Food and Drug Administration approval of a psilocybin therapy for a mental health condition.

The late-stage study, known as COMP006, enrolled 581 participants across North America and Europe. Researchers compared two fixed 25 mg doses of COMP360, administered three weeks apart, with a 1 mg control dose. By week six, patients receiving the 25 mg dose showed a statistically significant reduction in depressive symptoms. The average improvement measured 3.8 points on the Montgomery-Åsberg Depression Rating Scale compared with the control group, with a p-value below 0.001.

The company also released 26-week durability data from its first phase 3 trial, COMP005, which met its primary endpoint in June 2025 with an average treatment difference of 3.6 points versus placebo. According to a filing with the US Securities and Exchange Commission, 25 percent of participants in the 25 mg group maintained a clinically meaningful improvement for six months after receiving one or two doses. More than 40 percent of patients who initially improved but had not achieved remission at six weeks entered remission after receiving a second dose.

Chief executive Kabir Nath said the results across three large clinical trials involving more than 1,000 participants demonstrated consistent and statistically significant outcomes on the primary endpoint, along with clinically meaningful effects in patients with treatment-resistant depression. He described the findings as an important development in psychiatric research, particularly in a population where demonstrating therapeutic benefit has historically been difficult.

Compass has requested a meeting with the US Food and Drug Administration to discuss a rolling submission and review process for its planned New Drug Application. The company expects to complete its filing in the fourth quarter of 2026. COMP360 has been granted Breakthrough Therapy designation by the FDA, a status intended to speed the development and review of medicines for serious conditions when preliminary evidence suggests substantial improvement over existing therapies.

In the COMP006 trial, 39 percent of participants in the 25 mg group achieved a clinically meaningful reduction in their depression scores by week six. Safety data indicated that most adverse events, including headache, nausea, anxiety and visual hallucinations, occurred on dosing days and resolved within 24 hours. Across both phase 3 studies, the rate of serious adverse events related to suicidal ideation was reported at below 1 percent.

Treatment-resistant depression, defined as depression that has not responded to multiple prior medications, affects millions of patients who have limited therapeutic options. If approved, COMP360 would represent a shift from daily antidepressant regimens toward an episodic treatment model, with the potential for sustained benefit following one or two supervised dosing sessions.