Compass guides magic mushroom drug through early safety test

A synthetic form of the active ingredient in magic mushrooms has cleared an early-phase trial. The drug, Compass Pathways’ COMP360, came through the placebo-controlled phase 1 without setting off any safety alarms, setting the stage for further tests in treatment-resistant depression. 

Psilocybin, the active ingredient in psychedelic mushrooms, has shown promise in depression but is yet to be put through the sort of rigorous tests needed to support regulatory approval. That is starting to change, in part because of the efforts of Compass and King's College London. Compass shared top-line findings from a study in 89 healthy volunteers run with the academic center today.

The trial saw no serious adverse events. As expected, most of the adverse events in the treatment arms were psychedelic in nature, with participants reporting changes in sensory perceptions and positive effects on their mood. The trial saw no negative effects on cognition or emotions. 

Those findings are in line with knowledge of the effects of psilocybin, although in this case they come with the added credibility of coming from a placebo-controlled trial. 

As well as looking at safety and tolerability, the study evaluated the feasibility of a model for giving COMP360 to people. Each subject had one-to-one support from a trained assisting therapist for six hours when they received their dose, ensuring someone would be on hand to provide reassurance when the psilocybin kicked in.

The study had up to six of these one-on-one sessions running simultaneously. Those multisubject sessions passed without incident, giving Compass confidence that the treatment model is feasible. 

While the findings suggest COMP360 can be administered safely, they say nothing about whether the drug is efficacious. A clearer picture of that key element could emerge in the next year or so when Compass shares data from a phase 2 that is giving COMP360 to 216 people with treatment-resistant depression. 

The clinical trial is tracking the effect of three doses of the drug on scores on a depression scale for up to 12 weeks. However, as the trial lacks a control arm, the results it generates are unlikely to be conclusive. A high placebo response rate is a characteristic of many depression studies, meaning the absence of a control arm will make it hard to rule out the possibility that factors other than the drug are behind any improvements.