The World’s Largest Psilocybin Therapy Trial Is Close to Completion. Why Does This Matter?

Photo by Christopher Ott | Unsplash


Photo by Christopher Ott | Unsplash

Over the last few years, against a backdrop of a growing global mental health crisis, excitement has been building around psychedelic therapies that appear to have an extraordinary capacity to create life-changing experiences.


Psilocybin therapy is one of the most promising innovations in psychiatry today and has the potential to transform the lives of millions of people suffering with mental health challenges. In the model of psilocybin therapy we are developing at COMPASS Pathways, our synthetic psilocybin, COMP360, is administered in conjunction with psychological support from specially trained therapists. COMP360 has been designated a Breakthrough Therapy by the US Food and Drug Administration (FDA), for treatment-resistant depression (TRD), indicating that the regulator believes this therapy may show substantial improvement over existing treatments.


Earlier this month, we announced the completion of the psilocybin administration phase of our phase IIb clinical trial of COMP360 psilocybin therapy for TRD. Taking place in 22 sites and 10 countries, with 233 patients, this is the world’s largest psilocybin therapy trial. Data are expected later in the year.


This is a huge milestone and marks a pivotal moment in our quest to develop better treatments for the 100 million people worldwide who are not helped by existing treatments such as antidepressants, and who are labeled “treatment-resistant”. Depression is one of the leading causes of disability worldwide, affecting more than 320 million people worldwide and 17 million people in the US. According to the World Health Organization, every 40 seconds, one person dies from suicide, and in that same time, another 20 people attempt it. Approximately 90% of those who die from suicide in the US have an underlying mental illness, and many suffer with depression. It’s no surprise that COVID has exacerbated this mental health crisis. The Centers for Disease Control and Prevention have reported that more than 40% of adults in the US had suffered symptoms of anxiety and depressive disorders during the pandemic.


In the face of this significant unmet need, early signals from academic studies have shown that psilocybin therapy has the potential to improve outcomes for patients suffering with TRD, with rapid reductions in depression symptoms and effects lasting up to six months, after administration of a single high dose. In April this year, the New England Journal of Medicine published a small study conducted by Imperial College London, in which psilocybin therapy was compared with an antidepressant for the first time, in patients with major depressive disorder. The study showed signals of positive activity in COMP360 psilocybin compared with one of the most prescribed antidepressants, escitalopram, and concluded that larger studies were needed.


Psilocybin and other psychedelics are also enjoying the legislative spotlight. Psilocybin has now been decriminalized in Oregon; Ann Arbor, MI; Denver, CO; Oakland, CA; Santa Clara, CA; and Washington, DC, reflecting a continuing shift in public and political favor. A legalization measure was passed in Oregon last November, kickstarting a two-year development program looking at how to bring psilocybin to people in supervised, licensed facilities.


While we welcome the growing interest in psilocybin and its potential, our focus remains firmly on helping those with serious mental health illnesses, rather than on making psychedelic therapy available to everyone.


This means we need to get psilocybin therapy approved by regulators, reimbursed, and integrated into the health system. It must be prescribed by doctors and paid for by insurers or their equivalents. Only then does it become truly accessible.


Working backward from this goal, payers are looking for therapies that have been approved by regulators and can demonstrate cost-effectiveness as well as improved outcomes for patients. Regulators will approve therapies that show safety, efficacy, and quality, evidenced by data generated in rigorous, large-scale clinical trials.


Our phase IIb study is not about psychedelics, it’s about mental health. It’s about generating data that will, we hope, enable us to progress to a pivotal phase III trial, and from there to regulatory approval, with support from payers, by 2024/25. This is the best chance we have of bringing this much-needed innovation, quickly and safely, to patients suffering with serious mental health illnesses, regardless of their ability to pay – and on a large scale.


The completion of the trial is the culmination of a tremendous effort by hundreds of people. We are privileged to be working with a talented and dedicated team across our 22 trial sites, as well as our supply chain and clinical research partners. The data generated will enable us to move closer to our goal of helping millions of patients in urgent need of better mental health care. That’s why it matters.


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