New England Journal of Medicine publishes exploratory study showing signals of positive activity in COMP360 psilocybin compared with escitalopram for major depressive disorder

Study concludes that psilocybin findings should be explored further in larger studies

London, UK, April 15, 2021 (GLOBE NEWSWIRE) -- COMPASS Pathways plc (Nasdaq: CMPS) (“COMPASS”), a mental health care company dedicated to accelerating patient access to evidence-based innovation in mental health, welcomed a study published in the New England Journal of Medicine (NEJM) yesterday, which showed signals of positive activity in COMP360 psilocybin compared with the standard antidepressant escitalopram, for major depressive disorder (MDD).

The study was designed and conducted by a research team at Imperial College London, using COMPASS’s COMP360 psilocybin.

This was an exploratory, randomised, double-blind clinical study. Its aim was to compare the efficacy and mechanisms of action of psilocybin with a six-week course of escitalopram, a selective serotonin reuptake inhibitor (SSRI), for MDD.

The study included 59 participants; 30 were randomly assigned to the psilocybin arm, and 29 to the escitalopram arm. Participants in the psilocybin arm received two doses of 25mg psilocybin three weeks apart, with psychological support delivered prior to, during and after each psilocybin administration, plus six weeks of daily placebo capsules. The escitalopram arm received two doses of 1mg psilocybin (presumed negligible effect) three weeks apart, with equivalent psychological support to the psilocybin arm, plus six weeks of daily escitalopram capsules, 10mg for the first three weeks titrated to 20mg for the following three weeks.

The study authors, from Imperial College London, noted that the study was not powered to detect a difference between psilocybin and escitalopram. As reported in the NEJM, the primary efficacy measure, the change from baseline in the self-rated 16-item Quick Inventory of Depressive Symptomatology (QIDS-SR-16) total score at six weeks, did not show a significant difference between the two groups, with a two point difference favouring the psilocybin group compared with the escitalopram group. This trend favouring psilocybin was present from week one.

Secondary outcomes including clinician-rated depression scales, response and remission, signalled the antidepressant effects of both agents; psilocybin showed numerical advantages on clinical measures compared with escitalopram. On the clinician-rated depression scales, the change from baseline at week six on the Montgomery-Asberg Depression Rating Scale (MADRS), showed a 7.2 point treatment difference favouring psilocybin, while the Hamilton Depression Rating Scale (HAM-D-17) showed a 5.3 point treatment difference favouring psilocybin. Response rates (a 50% or greater reduction on the QIDS-SR-16 total score from baseline) at week six were 70.2% for the psilocybin arm compared with 48.0% for the escitalopram arm, and remission rates (defined as a QIDS-SR-16 total score ≤5) at week six were 57.1% and 29.1%, respectively. Similar patterns favouring psilocybin were found in other secondary endpoints measuring work and social functioning, anxiety, avoidance, anhedonia, and wellbeing. Such secondary endpoints were uncorrected for multiplicity.