Compass Pathways reported that 39% of patients in the 25 milligrams arm of a phase 3 trial for highly chronic treatment-resistant depression achieved a clinically meaningful response after two doses of its synthetic, proprietary formulation of psilocybin and maintained that benefit through at least 26 weeks, according to a July 7 news release.
COMP006 is an ongoing randomized, double-blind phase 3 trial of Compass Pathways’ investigational COMP360 psilocybin treatment in 581 dosed participants with treatment-resistant depression across North America and Europe. Participants were randomly assigned to receive 25 milligrams, 10 milligrams or 1 milligrams of COMP360 in two fixed doses administered three weeks apart. The newly reported findings are from the blinded 26-week Part B of the 52-week study.
Participants had current depressive episodes lasting, on average, more than three years and more than six lifetime depressive episodes, reflecting a highly treatment-resistant population.
Here are six things to know:
- The second phase 3 trial confirmed durable results. The 26-week results from Part B of the ongoing COMP006 trial confirmed COMP360’s rapid onset and durable profile for treatment-resistant depression. Compass said the findings build on results from the first phase 3 study, COMP005, which also demonstrated durable benefit through at least six months.
- Nearly 40% of patients responded after two doses. Among participants receiving the 25 milligrams dose, 39% achieved a clinically meaningful reduction in Montgomery-Åsberg Depression Rating Scale scores of at least 25% by week six after two fixed doses of COMP360 and maintained that response through at least week 26. Compass said this compares with 25% of patients in COMP005 who achieved the same response after a single dose.
- Some patients achieved remission after retreatment. Compass said nearly 30% of participants who achieved a clinically meaningful response at week six later went into remission after retreatment during Part B of the study.
- No new safety findings emerged. The company said COMP360 continued to demonstrate a generally well-tolerated and safe profile. Most treatment-emergent adverse events were transient and occurred on the day of dosing. Serious adverse events occurred in 6.3% of participants receiving 1 milligrams and 5.7% of those receiving 25 milligrams over 26 weeks.
- The FDA review is already underway. Compass said it has begun a rolling New Drug Application submission with the FDA and remains on track to complete the submission in Q4 2026.
- A commercial launch could follow in 2027. The company said it anticipates launching COMP360 in the first half of 2027, subject to FDA approval and Drug Enforcement Administration rescheduling.
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