Reunion Neuroscience has reported a mid-stage success with its short-acting psychedelic drug in postpartum depression (PPD), paving the way for the company to initiate a registrational trial next year.
The biotech’s candidate, known as RE104, met the primary endpoint of change in the Montgomery-Åsberg Depression Rating Scale (MADRS) total score at seven days in a Phase 2 trial called RECONNECT. The drug given at 30 mg produced a 23-point MADRS reduction versus a 17.2-point reduction for the active control arm, which translates to a p-value of 0.0094.
Participants in the control arm received a 1.5 mg dose of RE104. Using a subtherapeutic dose of a drug as control is a common strategy in psychedelic trials, because opting for a traditional placebo can result in what’s known as functional unblinding and expectation bias.
The Phase 2 study enrolled 84 adults with moderate to severe PPD, according to a Monday release.
RE104 is a short-acting prodrug of a psychedelic compound called 4-OH-DiPT, which is similar to psilocybin. It is given as a single dose without psychotherapy and most patients are ready for discharge within four hours of injection, Reunion said.
The biotech plans to advance RE104 into a Phase 3 PPD study in 2026. The Phase 3 will likely need to include a standard placebo arm and potentially a third arm that contains an active but lower dose of RE104, Reunion’s chief medical officer Mark Pollack told
Endpoints News
in an interview.
Current treatments for PPD are “slow-acting and burdensome,” lead investigator Anita Clayton said in the release. Sage and Biogen’s Zurzuvae
secured FDA approval
for the condition in 2023 based on data from a pair of Phase 3 studies which showed it improved symptoms as early as three days. Before Zurzuvae, patients only had access to treatments that took several weeks to work.
RE104 achieved “clinically meaningful reductions” in MADRS as soon as the first day after administration in the Phase 2 study, according to Reunion. Just over 70% of patients in the treatment arm were in remission at seven days compared with 41% of patients in the active control group.
Remission rates in most depression trials are “maybe half or even a third” of what RE104 achieved in the mid-stage trial, Pollack said. “So to see that kind of rapid movement of patients [in the study] into remission is unusual” in a positive way, he said.
The drug is also in development for adjustment disorder related to cancer and other medical illnesses, with a Phase 2 trial due to start in the third quarter.
Reunion was a publicly traded company, but was
taken private
in 2023 by the investment firm MPM BioImpact. The biotech secured
$103 million
in a Series A raise last year that was supported by MPM and Novo Holdings, among others. The cash should fund its activities through 2027.
Reunion said it is fully prepared to potentially launch and commercialize RE104 by itself.
Editor’s note: This article was updated throughout with interview comments from Reunion.