Compass Pathways Reports Positive Phase 3 Data for Psilocybin Depression Treatment

Compass Pathways' stock rose 31% after the company posted positive Phase III data for its investigational psychedelic, COMP360, in treatment-resistant depression (TRD). The company disclosed new clinical data from Part A and Part B from COMP005 and Part A from COMP006 on February 17 at 6:30 am ET.

During the ongoing, global COMP006 trial (NCT05711940), a 25mg dose of the synthetic psilocybin-based psychedelic met its primary trial endpoint, triggering a statistically significant 3.8-point reduction in Montgomery-Åsberg Depression Rating Scale (MADRS) scores from baseline compared with a 1mg control dose. Patients received two doses of COMP360 at the start of the trial and at three weeks.

COMP360 also triggered a clinically meaningful MADRS score reduction, classified as a 25% decrease from baseline or more, in 39% of patients at week six. Of these patients, all experienced a statistically significant rapid onset of benefit from the day after administration. COMP360 maintained its impact across all measured timepoints through to week six.

New data from the COMP005 study (NCT05624268) uncovers the durability of COMP360's efficacy, as 25% of patients in the 25mg cohort achieved clinically meaningful MADRS reductions through 26 weeks after one or two doses.

Previous data from the COMP005 trial, released in June 2025, was met with hesitancy. While the study met its primary endpoint, the data was not as strong as Compass had hoped, which saw the biotech's stock value drop more than 50%. Investors are more impressed by the newest data, with the outcomes of the COMP005 and COMP006 trials having sent Compass' stock value up 31% from $5.81 at market close on 13 February to $7.63 at the same time on 17 February.

The psychedelic was proven to be safe and tolerable in both the COMP005 and COMP006 trials, with eight (5%) and six (2%) patients experiencing severe treatment-emergent adverse events (TEAE), respectively, during each study. The most common TEAEs across both studies were headache, nausea, anxiety and visual hallucination.

Following the results of these two Phase III studies in TRD, Compass plans to submit a new drug application (NDA) for COMP360 in Q4 2026. Compass is also hoping to be commercially ready by the end of 2026.

If approved, COMP360 would likely become the first classic psychedelic to get the regulatory greenlight for the treatment of a mental health condition. This comes after Lykos Therapeutics' midomafetamine (MDMA) therapy for post-traumatic stress disorder (PTSD) missed out on achieving this milestone due to trial design concerns.

In an investor call discussing data from the COMP005 and 006 studies, Compass executives noted that COMP360 could have "blockbuster potential" due to its highly differentiated approach. The company also highlighted COMP360's reduced dosing burden compared with Johnson & Johnson's Spravato (esketamine), which became the first monotherapy to gain FDA approval in TRD back in 2025 following its initial 2019 approval in combination with oral antidepressants. GlobalData forecasts that Spravato will generate $3.8bn in sales for J&J in 2031.

GlobalData forecasts that COMP360 will generate sales of $879m in 2031.

COMP360 has received Breakthrough Therapy designation from the U.S. Food and Drug Administration and Innovative Licensing and Access Pathway designation in the UK for treatment-resistant depression. The synthetic psilocybin treatment is being developed as a potential first-in-class therapy for patients with serious mental health conditions who have not responded to existing treatments.

Unlike many antidepressant medications, psychedelic therapies must be used under the supervision of a trained healthcare professional, meaning patients must travel to the clinic to receive such therapies. The CEO views the increased uptake of Spravato as a good springboard to COMP360's success on the market. This is because the "continued increase in interventional psychiatry clinic infrastructure" driven by the drug will facilitate the drug's effective integration.

The company received acceptance from the U.S. Food and Drug Administration for its Investigational New Drug application, allowing it to initiate a Phase 2b/3 clinical trial for its COMP360 treatment in post-traumatic stress disorder (PTSD) patients. This trial will explore the treatment's efficacy, safety, and tolerability.

Compass Pathways is headquartered in London with additional offices in New York. The company is listed on the Nasdaq stock exchange. The biotech firm is currently valued at approximately $558 million.