Reunion's Psychedelic Drug Shows Promise in Postpartum Depression, Advancing to Late-Stage Trials

Reunion Neuroscience, a small New Jersey-based drug developer, has announced positive results from a phase 2 study of its experimental psychedelic compound RE104 for the treatment of postpartum depression (PPD). The success of this trial paves the way for late-stage testing, potentially offering a new treatment option for a condition that affects approximately 15% of new mothers within a year of giving birth.

Promising Phase 2 Results

The mid-stage study enrolled 84 women with moderate to severe postpartum depression, divided into two groups. One group received a full 30 mg dose of RE104, while the other served as an "active control" arm, receiving a much lower dose of 1.5 mg.

Key findings from the study include:

• The 30 mg group showed significantly greater reductions on a widely used depression scale, with scores falling by 23 points after seven days, compared to 17.2 points in the control arm.
• 77.1% of patients in the 30 mg group saw at least a 50% improvement in depression scores at Day 7, versus 61.6% in the control group.
• 71.4% of patients in the 30 mg group achieved "remission" of their depression symptoms at Day 7, compared to 41% in the control group.
• The drug was well-tolerated, with no serious adverse events reported.

Dr. Anita Clayton, the trial's lead investigator and chair of psychiatry and neurobehavioral sciences at the University of Virginia School of Medicine, called the findings "promising" in light of the limited treatment options currently available for PPD.

Advancing to Phase 3 and Expanding Applications

Based on these favorable results, Reunion plans to initiate a Phase 3 trial of RE104 for postpartum depression in 2026. The company is also exploring the drug's potential in other mental health conditions:

• A Phase 2 study for adjustment disorder related to cancer and other medical illnesses is set to begin later this year.
• Another Phase 2 trial for an undisclosed "significant mental health indication" is planned for early 2026.

Additionally, preliminary results from a clinical lactation study suggest that mothers may be able to return to breastfeeding shortly after RE104 treatment, with metabolite levels in breast milk falling below potentially risky thresholds for infants.

Financial Backing and Industry Context

Reunion's progress comes on the heels of significant financial support. In May 2024, the company raised $103 million in a Series A funding round co-led by MPM Capital and attracting investors such as Novo Holdings, the parent company of Novo Nordisk.

The development of RE104 is part of a broader trend in psychedelic medicine research. The drug functions similarly to psilocybin, a compound found in some psychedelic mushroom species, but is designed to have a shorter duration of effect. This could potentially offer advantages over other psychedelic treatments in development, such as Compass Pathways' COMP360, which recently showed positive results in a Phase 3 trial for treatment-resistant depression.

As Reunion advances RE104 into late-stage trials, it joins a growing field of companies exploring psychedelic compounds for mental health conditions, potentially reshaping treatment paradigms for disorders like postpartum depression in the coming years.