Compass Pathways’ New Psilocybin For Depression Trial, Explained

The article Compass Pathways’ New Psilocybin For Depression Trial, Explained was originally published on Microdose.

On February 17th, psychedelic medicine company Compass Pathways (Nasdaq: CMPS) registered a new Phase 2 clinical trial attempting to treat Major Depressive Disorder using psilocybin-assisted therapy.

The new trial will include 102 Major Depressive Disorder patients, two-thirds of whom will receive 25 mg of Comp360 — a large, hallucinogenic dose of Compass Pathways’ proprietary formulation of psilocybin — while the last third will receive 1 mg — the placebo group. In order to be eligible for treatment, patients must have undergone one prior unsuccessful treatment combating their current depressive episode.

Before getting into more details about the new trial, let’s take a moment to discuss its significance for Compass Pathways, and the psychedelic medicines industry more generally.

Psilocybin for depression: Major Depressive Disorder or Treatment-Resistant Depression

To start, by attempting to treat Major Depressive Disorder with psilocybin therapy, Compass is expanding the potential patient pool for their psychedelic medicine. Until now, the company has been focused on treating Treatment-Resistant Depression (as well as other conditions such as PTSD and anorexia).

The distinction is important.

If a person has Treatment-Resistant Depression, it means that they have been diagnosed with Major Depressive Disorder and have unsuccessfully attempted at least two different forms of treatment. A treatment is usually considered successful if measured symptoms fall by at least 50%. In other words, people with Treatment-Resistant Depression are by definition the hardest individuals to treat.

By focusing on the Treatment-Resistant portion of those with depression, Compass was attempting to bring help to those who need it most. However, there are two key points that must therefore be made when discussing their treatment attempts.

First, by only treating those defined as Treatment-Resistant, Compass’ Comp360-therapy  program left out the majority of people with depression. Though estimates vary, only around 29% to 46% of depression patients can be considered “Treatment-Resistant.” Therefore, with Compass’ new trial, they are greatly expanding the potential number of patients that they hope to treat if Comp360-therapy is approved (however, the requirement that patients must have had one prior unsuccessful treatment does limit the expansion somewhat).

Expanding the pool of patients, and potential for stronger results

Next, as well as expanding the number of potential patients, by attempting to treat people whose depression may be less severe, it is possible that Compass may achieve more impressive clinical trial results for this trial than for their Treatment-Resistant patients — though of course this is speculation and must be born out in the data.

Compass is preparing to start two separate Phase 3 trials attempting to treat Treatment-Resistant Depression with psilocybin therapy. This follows their already completed Phase 2b trial attempting the same thing.

That trial saw positive results, though not as breathtaking as other psychedelic medicine trials. It found that three weeks after treatment, 36.7% of patients saw a decrease in their depressive symptoms of at least 50% — as measured by the MADRS scale — though this decreased to 24.1% after 12 weeks.

While perhaps not revolutionary numbers, bringing relief to almost a quarter of patients who had tried at least twice previously to ameliorate their symptoms is still very impressive. Hopefully, psilocybin therapy will be even more effective for those with a less severe diagnosis.

In sum then, if Compass Pathways’ successfully brings their psilocybin therapy for Major Depressive Disorder treatment through the full clinical trial process, it will allow the company to treat a greater number of depressed patients, and hopefully the success rate for those with a less severe form of depression is greater.

It must be noted that from a business perspective, Compass faces lots of competition in the psilocybin therapy for Major Depressive Disorder space. Companies such as Braxia Scientific (CSE: BRAX, OTC: BRAXF), Cybin (NEO:CYBN, NYSE American:CYBN), and MindSet Pharma (CSE:MSET, OTCQB:MSSTF) are all developing psilocybin or psilocybin analogs for the treatment of Major Depressive Disorder, as are nonprofits such as Usona and Beckley Psytech.

From a humanist perspective, however, this is a very good thing as the competition between institutions will help ensure that patients eventually receive the best version of psilocybin therapy possible.

Returning to the clinical trial at hand, the primary objectives of the trial are to measure the “Safety and tolerability of COMP360 Psilocybin”, as well as the “Proportion of patients with adverse events.”

As there have already been many psilocybin trials up to this point, it is likely that Compass will find Comp360 safe and tolerable, and most adverse events will likely not be serious.

We are more interested in the so-called “secondary outcome measures.” The most interesting is the change in depression levels three and six weeks after treatment, as compared to what they were before treatment, using the MADRS scale.

The other is measuring the plasma concentration of psilocybin and other compounds in patients. This is important for seeing how similar the effects of a given dose of psilocybin are between individuals.

As this trial is newly announced, and Compass is just beginning recruitment, it will likely be more than a year before we see data. Nevertheless, this move increases the probability that those suffering from Major Depressive Disorder will get a treatment that works for them. 

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