Compass Pathways Reports Phase 3 Success for Psilocybin Depression Treatment

Compass Pathways announced successful results from its Phase 3 trial (COMP006) for COMP360, a pharmaceutical-grade synthetic version of psilocybin designed to treat Treatment-Resistant Depression (TRD). The condition affects 4 million adults in the USA alone and is defined as a condition where a patient has tried at least two different antidepressant medications without seeing a significant improvement.

The results of the two Phase 3 trials (COMP005 and COMP006) together with Phase 2b data represent a robust dataset of over 1,000 participants. COMP005 included only USA participants, while COMP006 included individuals from Europe and Canada as well as the USA.

In COMP005, 25% of participants achieved a clinically meaningful reduction in Montgomery-Åsberg Depression Rating Scale (MADRS) scores at Week 6, with that response maintained through 26 weeks after just one or two 25mg doses. COMP006 confirmed that the 25mg dose remains the preferred dose, showing a statistically significant difference of -3.8 MADRS against the 1mg control at Week 6.

Significant differences in symptoms were demonstrated the day after administration, representing a rapid onset of action. This stands in stark contrast to traditional SSRIs, which often require a "test drive" of several weeks before a clinician can determine if they are effective.

The data suggests that retreatment can be a powerful tool. In Part B of the COMP005 trial, over 40% of patients who showed progress but had not yet remitted by Week 6 went into full remission after receiving a second dose.

COMP360 is a standardised chemical entity designed for use within a strictly controlled medical framework. The therapy is delivered through a unique three-step treatment model involving preparation, administration in a clinical setting with a therapist present, and integration sessions to help patients process insights gained during the session.

Currently, TRD has only 1 approved drug in the USA (Spravato). In the UK, MHRA requires strict supervision for the administration of Spravato as it is classified as a Schedule 2 controlled substance. The company is currently moving through a rolling submission process and expects to complete their full New Drug Application (NDA) by the 4th quarter.

According to the STAR D trial (Sequenced Treatment Alternatives to Relieve Depression), the chances of achieving remission are essentially cut in half once a patient is forced to move to a third line of antidepressants. TRD is associated with significantly longer episode duration, individuals are more likely to have chronic depression greater than 2 years, time till remission is longer, and relapse rates are higher. Those with TRD face a significantly higher risk of suicide.