COMPASS Pathways plc (Nasdaq: CMPS), a biotechnology company dedicated to accelerating patient access to evidence-based innovation in mental health, today announced that positive data from an open-label phase 2 clinical trial of investigational COMP360 psilocybin in addition to daily selective serotonin reuptake inhibitors (SSRIs) in treatment-resistant depression has been published online in the peer reviewed Nature journal, Neuropsychopharmacology.

The exploratory phase 2 clinical trial used an open-label, fixed-dose design to investigate the safety and efficacy of a single dose of 25mg of COMP360 psilocybin with psychological support, in addition to an SSRI, in 19 participants experiencing treatment-resistant depression. The findings were first announced in December 2021.

Results:

  • Response (a greater than 50% reduction from baseline in MADRS total score1) and remission (MADRS total score of 10 or less) was seen in 42% of participants at week three.
  • The efficacy findings were similar to those from COMPASS’s Phase 2b study of 25mg of COMP360 psilocybin in treatment-resistant depression, where patients were withdrawn from their antidepressants prior to receiving COMP360 (42% response and remission rates at week three versus 37% and 29%, respectively).
  • COMP360 psilocybin treatment was generally well tolerated. The most common treatment emergent adverse event was headache. No serious adverse events were reported.

“It has long been thought that SSRIs could interfere with the potential therapeutic effect of psilocybin. This data is exciting because it provides a preliminary signal that this is not the case, and that patients could remain on their SSRI antidepressant medication and experience the same effect from COMP360 psilocybin treatment as people who are not on SSRIs. This could have important clinical implications for patient choice, if COMP360 psilocybin treatment receives regulatory approval for treatment-resistant depression. Withdrawing from antidepressants can be unwelcome for some patients, so the possibility of having the choice to remain on their antidepressant could eventually make COMP360 psilocybin treatment more accessible.”

Dr. Guy Goodwin, Chief Medical Officer at COMPASS Pathways

COMP360 is COMPASS’s investigational proprietary formulation of synthetic psilocybin, administered in conjunction with psychological support. COMPASS is currently conducting a phase 3 clinical program of COMP360 psilocybin treatment in treatment-resistant depression, the largest of its kind ever conducted. This program follows positive results from COMPASS’s phase 2b trial published in the New England Journal of Medicine.

About COMPASS Pathways

COMPASS Pathways plc is a biotechnology company dedicated to accelerating patient access to evidence-based innovation in mental health. Our focus is on improving the lives of those who are suffering with mental health challenges and who are not helped by current treatments. We are pioneering the development of a new model of psilocybin treatment, in which our proprietary formulation of synthetic psilocybin, COMP360, is administered in conjunction with psychological support. COMP360 has been designated a Breakthrough Therapy by the U.S. Food and Drug Administration (FDA) and has received Innovative Licensing and Access Pathway (ILAP) designation in the UK for treatment-resistant depression (TRD).

We have commenced a phase 3 clinical program of COMP360 psilocybin treatment in TRD, the largest randomized, controlled, double-blind psilocybin treatment clinical program ever conducted. Previously, we completed a phase 2b study with top line data showing a statistically significant (p<0.001) and clinically relevant improvement in depressive symptom severity after three weeks for patients who received a single 25mg dose of COMP360 psilocybin with psychological support. We are also conducting phase 2 clinical studies of COMP360 psilocybin treatment for post-traumatic stress disorder (PTSD) and anorexia nervosa.