Improvement in Depression Symptoms Measured by Montgomery-Åsberg Depression Rating Scale and Quick Inventory of Depressive Symptomatology-Self Rated Items after Randomised Double-blind COMP360 Psilocybin Therapy for Treatment-resistant Depression

Introduction COMP360 is a synthetic, proprietary, purified form of psilocybin in development for treatment-resistant depression (TRD) with FDA Breakthrough Therapy designation. In recent phase IIb study, 25mg was superior to 1mg on change from baseline (CFB) Week 3 the Montgomery-Åsberg Depression Rating Scale (MADRS) total score (primary efficacy endpoint), when administered alongside psychological support. Quick Inventory Depressive Symptomatology-Self Rated (QIDS-SR 16 ) (exploratory endpoint) showed similar results. Objectives To analyse changes specific symptoms after treatment aforementioned as measured by individual item scores MADRS and QIDS-SR (range 0-6 0-3). Methods Participants TRD were randomised single doses (n=79), 10mg (n=75), or (n=79). A remote, blinded rater assessed at Baseline, Day 2 (the day post-psilocybin), Weeks 1, 3, 6, 9, 12. The self-rated 2, At each time point, descriptive statistics calculated score. Results items largest differences mean CFB arm Inability Feel, Apparent Sadness, Lassitude, Reported Sadness. Greater improvement apparent remained 12 (Lassitude 6 only). On , difference Feeling Sad evident (Table 1). Table 1. Item (mean [standard deviation]) Psilocybin - Feel -1.8 [1.81] -0.9 [1.54] -0.8 [1.61] Sadness -1.7 [1.94] -1.1 [1.60] [1.62] Lassitude -1.6 -1.2 [1.83] [1.58] [1.95] -1.0 [1.52] -0.6 [1.53] [1.08] [1.07] -0.4 [0.91] Conclusions administration therapy rapidly dose-relatedly improved depressed mood anhedonia – two key depression. As predictive poorer response, improvements correlate functioning, it important understand impact treatments this symptom. Disclosure Interest G. Goodwin Shareolder of: COMPASS Pathways, P1Vital, P1Vital products Employee L. Marwood S. Mistry A. Nowakowska H. Simmons J. Tsai Williams M. Young E. Malievskaia Pathways