Psilocybin Therapy Combined With SSRI Antidepressants Is Possible, COMPASS Study Confirms

Psilocybin-focused mental health care company COMPASS Pathways plc CMPS announced Monday it had achieved positive results from its exploratory study of COMP360 psilocybin therapy in conjunction with SSRI use. SSRI, or selective serotonin reuptake inhibitors, are the most commonly prescribed antidepressants.

The study revealed that SSRI medications combined with psilocybin treatment do not interfere with psilocybin’s therapeutic effect.

Study Highlights And Results

• This open-label study included 19 patients from clinical sites in Ireland and the United States. The majority of patients were female (68.4%) and the average age was 42 years. The primary endpoint was the change in baseline MADRS1 total score at 3 weeks in patients having 25mg COMP360 psilocybin therapy given in augmentation with their existing SSRI antidepressant regimen.

• COMP360 psilocybin therapy using a 25mg dose showed overall signs of improvement in most other measures including improvement in anxiety, clinician and self-rated depressive symptoms, and positive and negative affect.
• 25mg COMP360 psilocybin therapy was generally well-tolerated when it was administered simultaneously with the patient’s SSRI treatment. There were no treatment-emergent adverse events (TEAEs) classed as serious (life-threatening, leading to disabilities, hospitalisation or in general medically significant) and no TEAEs related to suicidal ideation or behaviour or intentional self-injury.

“The results of this study challenge the widely-held belief that the use of SSRI medication together with psilocybin could interfere with psilocybin’s therapeutic effect,” Guy Goodwin, COMPASS Pathways’ chief medical officer said. "Our findings provide a strong signal that COMP360 psilocybin therapy could be an adjunctive treatment to SSRI antidepressant as well as a monotherapy. For some patients with treatment-resistant depression, withdrawal is a difficult step even though, by definition, ‘treatment-resistant’ means that those antidepressants are not working. This is exactly why we conduct rigorous research to help guide our clinical trial design - including addressing barriers to adoption of COMP360 therapy.”

The company is preparing for a meeting with the FDA in early 2022 and will include these results in that discussion. COMPASS expects to finalize a phase III program design with the FDA and anticipates commencing that program in Q3 2022.

Global Depression Disorder Statistics

More than 320 million people suffer from major depressive disorder (MDD), a leading cause of disability worldwide and one of the fastest-growing mental health conditions. About a third of these patients - 100 million - are not helped by existing therapies and suffer from treatment-resistant depression (TRD). As many as 30% of these attempt suicide at least once during their lifetime. The TRD population is by definition more difficult to treat and more likely to relapse than patients with major depressive disorder. In 2018, COMPASS received FDA Breakthrough Therapy designation for its COMP360 psilocybin therapy for TRD.

Price Action

COMPASS’ shares traded 0.95% higher at $25.58 during Monday pre-market session.

Photo: Courtesy of Mari-Liis Link on Unsplash