Researchers from King’s College London, in conjunction with mental health care company Compass Pathways, are reporting positive results from an early Phase 1 trial exploring the safety profile of different psilocybin doses in healthy adults. As well as demonstrating the psychedelic drug to be safe, with no serious adverse effects reported, the trial also explored the potential of group dosing sessions as a way to speed up research and expand patient access if the treatment is ultimately approved.
The trial data was revealed during a presentation at the annual meeting of the American College of Neuropsychopharmacology (ACNP). The double-blind, placebo controlled study is the largest trial conducted to date into the safety and tolerability of psilocybin. While Compass Pathways is currently conducting Phase 2b dose-ranging trials investigating the efficacy of psilocybin in subjects with treatment-resistant depression, this earlier study was focused on the effects and safety profile of the drug instead of any specific therapeutic efficacy.
The trial recruited 89 healthy subjects to compare the effects of a placebo against either 10 mg or 25 mg of psilocybin. In terms of demonstrating the safety profile of psilocybin, the trial suggests no serious adverse effects were reported from the acute day of dosage, up to 12 weeks of follow-up.
The trial revealed the psilocybin, of course, resulted in acute psychedelic effects on the day of dosage, but all of those hallucinatory ‘adverse effects’ resolved swiftly within hours, suggesting the drug does not cause residual negative psychoactive symptoms in the days or weeks following a dose. In other words, no subjects suffered from any kind of hallucinatory flashback in the weeks after taking psilocybin.
“The results of the study are clinically reassuring and support further development of psilocybin as a treatment for patients with mental health problems that haven’t improved with conventional therapy, such as treatment resistant depression,” says James Rucker, lead investigator on the study from King’s College London.
Perhaps one of the more interesting aspects of this trial was the secondary exploration into the feasibility of simultaneous group administration of psilocybin. The trial encompassed 25 dosing sessions, in a variety of different group size permutations, the largest of which comprised six subjects being treated in the same space simultaneously.
In these group sessions, each subject is accompanied by their own therapist, with the entire session supervised by a lead therapist and study psychiatrist. As Compass Pathways’ Communications Officer Tracey Cheung tells New Atlas via email, the motivation behind these group dosage experiments is primarily about exploring ways to streamline the treatment process. Scheduling more than one patient at a time offers the potential for accelerating the pace of clinical trials. Plus, looking further down the line, Cheung suggests this strategy could enhance patient access once the psychedelic treatment was approved and clinically deployed.
“This study is part of our overall clinical development program in treatment-resistant depression; we wanted to look at the safety and tolerability profile of our psilocybin, and to look at the feasibility of a model where up to six 1:1 sessions are held at the same time,” says Compass Pathways co-founder Ekaterina Malievskaia. “We are focused on getting psilocybin therapy safely to as many patients who would benefit from it as possible.”
There is no indication in the data presented so far to suggest the administration of psilocybin in this kind of group setting enhances the risk of negative responses to the treatment. The results presented at the annual ACNP meeting clearly state these simultaneous group dosages generated psychedelic effects that were consistent with what prior studies have identified. Plus, the researchers note the study achieved high retention rates with all participants willing to undergo this kind of simultaneous psilocybin administration.
However, it is worth noting, this particular study was conducted with psychologically healthy individuals, and not subjects suffering from mental health concerns. So, it is unclear at this point whether psychedelic group sessions are as efficacious from a treatment perspective.
After psilocybin therapy received a Breakthrough Therapy designation from the FDA late in 2018, Compass Pathways started a major international multi-site trial hoping to enrol over 200 subjects to test the efficacy of a range of psilocybin doses for treatment-resistant depression. A number of locations across Europe, Canada, the UK and US are still recruiting subjects so it may be some time before the large Phase 2 trial offers up clear results.
The new trial data was presented at the annual meeting of the American College of Neuropsychopharmacology (ACNP).
Source: Compass Pathways