Compass Pathways Plc (NASDAQ:CMPS) shares climbed 33.7% on Tuesday after the company disclosed highly statistically significant findings from its COMP006 Phase 3 trial of COMP360, the firm’s synthetic psilocybin formulation intended to treat treatment-resistant depression (TRD).
The company reported that the COMP006 study met its primary endpoint. Two administrations of COMP360 at a 25mg dose produced a mean difference of -3.8 points on the Montgomery-Åsberg Depression Rating Scale (MADRS) when compared with the 1mg dose control, with a p-value below 0.001.
In the latest trial, 39% of participants assigned to the 25mg arm reached what Compass described as a clinically meaningful reduction in depression symptoms by Week 6. The treatment effect showed a rapid onset, evident from the day after administration, and those improvements were sustained across the six-week assessment window.
Compass noted that responders in the earlier COMP005 Phase 3 study maintained durability of response through at least Week 26 after receiving one or two doses of COMP360, indicating potential for extended benefit following limited treatment sessions.
Safety results across both Phase 3 trials indicated a generally well-tolerated profile for COMP360. The company said most treatment-emergent adverse events occurred on the days of administration and typically resolved within 24 hours. The most commonly reported side effects were headache, nausea, and visual hallucination.
Following the COMP006 announcement, Compass said it has requested a meeting with the U.S. Food and Drug Administration to discuss a rolling submission and review pathway. The company also stated it plans to complete a New Drug Application submission in the fourth quarter.
"These data strengthen our conviction in the highly differentiated profile for COMP360 and given the urgent need for new treatments in TRD, we are advancing our discussions with the FDA, with the goal of submitting an NDA in Q4 and securing approval," said Kabir Nath, Chief Executive Officer at Compass Pathways.
The trial results mark a second successful Phase 3 study for Compass’s psilocybin therapy program and were linked by the company to both a favorable efficacy signal and a manageable short-term safety profile.
Summary
Compass Pathways reported highly statistically significant results from its COMP006 Phase 3 trial of COMP360, with the 25mg dose showing a -3.8 point mean difference versus 1mg on MADRS (p<0.001), 39% of participants in the 25mg arm achieving clinically meaningful improvement at Week 6, rapid onset of effect, and tolerability characterized by mostly short-lived administration-day adverse events. The company has requested an FDA meeting to discuss rolling submission and aims to file an NDA in Q4.
Key points
- Trial outcome: COMP006 met its primary endpoint with a statistically significant reduction in MADRS score for COMP360 25mg versus 1mg (mean difference -3.8, p<0.001).
- Efficacy and durability: 39% of participants in the 25mg arm achieved clinically meaningful symptom reduction at Week 6; responders from COMP005 maintained effects through at least Week 26.
- Safety and regulatory path: Safety profile generally well tolerated with common, short-duration adverse events; Compass has requested an FDA meeting and plans an NDA submission in the fourth quarter.
Risks and uncertainties
- Regulatory uncertainty - discussions with the FDA are ongoing and the outcome of a rolling submission or NDA review is not guaranteed; this impacts the biotech and pharmaceutical sectors.
- Safety considerations - while adverse events were generally short-lived, headache, nausea, and visual hallucination were commonly reported and will be considered by regulators and prescribers; this affects clinical adoption and commercial prospects.
- Durability data limitations - although COMP005 responders showed durability to Week 26, broader long-term effectiveness and real-world performance remain subject to further evaluation; this bears on payer decisions and market uptake.