Reunion Neuroscience has secured $103 million in Series A funding to advance its lead psychedelic compound RE104 for treating postpartum depression, marking a significant milestone for the company that was nearly delisted from Nasdaq just two years ago. The funding round was led by MPM Capital and Novo Holdings, with participation from Arkin Bio Ventures, Mitsui & Co. Global Investment, Plaisance Capital, FemHealth Ventures, and Palo Santo.
Novel Psychedelic Compound Shows Promise
RE104 represents a breakthrough in psychedelic medicine as a prodrug of 4-OH-DiPT, a synthetic compound structurally similar to psilocin found in "magic mushrooms." The key advantage of RE104 lies in its shortened duration of action. According to Phase 1 clinical trial data, RE104 produces "a psychedelic state similar in intensity and quality to psilocybin, but lasting only about half the time (3 to 4 hours)."
This shorter duration directly addresses recent FDA draft guidelines highlighting safety concerns with psychedelic treatments. The FDA noted that patients can remain in a vulnerable state for up to 12 hours during psychedelic sessions, necessitating the presence of two healthcare providers throughout treatment. RE104's abbreviated timeframe requires only about half a day in the clinic, potentially reducing resource requirements and improving treatment accessibility.
RECONNECT Trial Targets Postpartum Depression
The company has launched the RECONNECT Phase 2 clinical trial, with participant enrollment beginning by the end of June and results anticipated by the second quarter of next year. The double-blind randomized controlled trial will evaluate RE104's efficacy in treating postpartum depression, a condition affecting a significant portion of new mothers.
Eligible participants must be within 12 months postpartum and meet DSM-5 criteria for a postpartum major depressive episode with moderate to severe severity, defined as a HAM-D score of 24 or greater. The study specifically targets episodes with onset during the last trimester of pregnancy or within 4 weeks of delivery.
The trial excludes individuals with certain psychiatric conditions, including history of postpartum psychosis and current treatment-resistant depression, as well as those with significant suicide risk or prior psychedelic use. Participants receive either a single 30 mg subcutaneous dose of RE104 or a 1.5 mg comparator dose, with depression severity assessed at days 1, 7, 14, and 28.
Safety Considerations and Treatment Protocol
The RECONNECT trial includes important safety measures, requiring participants to stop breastfeeding before or at screening to prevent potential drug transfer to infants through breast milk. The study protocol does not specify whether breastfeeding can be resumed after drug administration.
The treatment protocol incorporates psychological support elements standard in psychedelic therapy, including a preparation session before the first dose and two integration sessions following medication administration. Notably, participants are not required to be hospitalized for the duration of the trial.
Mechanism of Action and Broader Applications
Like other compounds in Reunion's portfolio, RE104 targets the serotonin 2A receptor, a protein linked to learning, memory, and various mental disorders. This receptor is also the primary site where psychedelic drugs exert their hallucinogenic effects.
Beyond postpartum depression, Reunion is exploring RE104's potential in treating adjustment disorder in cancer patients, a condition characterized by maladaptive responses to cancer diagnosis lasting over two weeks. According to the company, approximately 40% of cancer patients develop mood disorders, representing a substantial unmet medical need.
Company Transformation and Market Context
The funding represents a remarkable turnaround for Reunion, which faced potential Nasdaq delisting due to minimum share price violations two years ago. Originally operating as Field Trip Health, the company underwent a strategic split in April 2022, with drug discovery activities rebranded as Reunion. Following the split, Reunion consolidated shares on a 5:1 basis to maintain Nasdaq compliance before agreeing to an all-cash acquisition by MPM valued at just over $13 million in May 2023.
The psychedelic drug development field has attracted increasing investment as companies work to overcome previous legal, scientific, and regulatory barriers. Compass Pathways raised nearly $150 million through an IPO in 2020 for psilocybin research targeting PTSD and depression, while Cybin secured $150 million in March through stock sales to selected investors.
Natalie Sacks, a venture partner at Novo Holdings, expressed optimism about RE104's potential, emphasizing its promise in improving outcomes for patients with limited treatment options. The investment reflects growing confidence in psychedelic medicine's therapeutic potential, particularly for conditions with significant unmet medical needs like postpartum depression.
