Until now, it has been commonly thought that selective serotonin reuptake inhibitors (SSRIs) could interfere with the therapeutic potential of psilocybin treatment. However, new results from a study show this may not be the case.
COMPASS Pathways has published results from its open-label study of its psilocybin treatment – a proprietary formulation of synthetic psilocybin called COMP360 – alongside antidepressants.
The results suggest that serotonin reuptake inhibitors (SSRIs) do not interfere with the potential therapeutic effect of the treatment.
The open-label, fixed-dose design study investigated the safety and efficacy of a single dose of 25mg of COMP360 psilocybin with psychological support, in addition to an SSRI.
Results of the exploratory Phase 2 trial, which involved 19 participants experiencing treatment-resistant depression, have been published in the Nature journal, Neuropsychopharmacology.
Chief Medical Officer at COMPASS Pathways, Dr Guy Goodwin, stated: “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.”
Study results
Results from the study showed a 50% reduction from baseline in participants’ Montgomery–Åsberg Depression Rating Scale (MADRS) total score – a measure used to establish the severity of depression – and showed remission (MADRS total score of 10 or less) in 42% of participants at week three.
Additionally, according to the results, COMP360 psilocybin treatment was well tolerated, with the most common adverse event being a headache.
COMPASS has stated that the efficacy findings were similar to those from its Phase 2b study of 25mg of COMP360 psilocybin in treatment-resistant depression, where patients were withdrawn from their antidepressants prior to receiving COMP360. This study showed 42% response and remission rates at week three versus 37% and 29%, respectively.
Goodwin added: “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.”
The company is currently conducting a Phase 3 clinical programme of COMP360 psilocybin treatment in treatment-resistant depression, the largest of its kind ever conducted.
