Reunion Neuroscience

Market position

Reunion competes in the psychedelic and neuropsychiatric therapeutics segment, positioning RE104/luvesilocin as a potential best-in-class, shorter-duration alternative to longer-acting psychedelics such as psilocybin, LSD and MDMA-assisted therapy. Sector context cited includes a reported 500% rise in psychedelic partnership deals between 2019 and 2023 and the FDA's 2024 rejection of Lykos' MDMA therapy, which prompted companies in the field to redesign trials.

The company differentiates luvesilocin on duration and practicality: a single subcutaneous dose producing an approximately three-to-four-hour psychoactive experience requiring about half a day of in-clinic monitoring, versus the six-to-eight hours typical of psilocybin, plus patent protection on the 4-OH-DiPT prodrug.

Technology

Luvesilocin (RE104) is a proprietary, patented prodrug of 4-OH-DiPT, a synthetic, shorter-acting psilocybin derivative that acts as an agonist at the serotonin 2A receptor (5-HT2AR). It is administered subcutaneously and is designed to produce a psychoactive experience of roughly three to four hours, compared with approximately six to eight hours for psilocybin, allowing administration within about half a day in the clinic under healthcare professional supervision. Phase 1 results reported the drug was well tolerated with robust pharmacodynamic effects, and were published in the Journal of Clinical Psychopharmacology.

Go-to-market

Development is advanced through company-sponsored clinical trials, FDA regulatory pathways including an investigational new drug application and Breakthrough Therapy Designation, peer-reviewed publication and scientific conference presentations (ACNP, ASCP, APA), and participation in investor conferences.

Patients with underserved mental health conditions, initially adult women with moderate-to-severe postpartum depression, patients with adjustment disorder related to cancer and other medical illnesses, and adults with generalized anxiety disorder; treatment is delivered in clinical settings under healthcare professional supervision. GAD is estimated to affect 6.8 million US adults annually, with about half of patients failing to respond to initial SSRI or SNRI treatment.

Geography

Headquartered in Morristown, New Jersey, United States; RE104 was initially investigated clinically in Australia before US IND clearance.

History

Reunion Neuroscience was formerly a publicly traded company. In June 2023 MPM BioImpact acquired Reunion in a $13.1 million take-private transaction; per then-CEO Greg Mayes, the deal was announced on June 1 and closed on August 1, roughly 60 days. After going private, the company launched a Series A financing anchored by MPM BioImpact, initially targeting $80 million and oversubscribed to $103 million, announced in May 2024 and co-led by MPM BioImpact and Novo Holdings. In September 2025 the final Series A tranche was increased following positive RECONNECT results, bringing the round total to $133 million. Greg Mayes was succeeded as President and CEO by Sahil V. Kirpekar, M.D., in June 2026.

Risks & controversies

The company operates in a sector where institutional healthcare investment has been limited and where psychedelic development is regarded by many investors as a "show-me story" on safety, efficacy and intellectual property protection. Sector-wide sentiment was affected by the FDA's August 2024 rejection of Lykos Therapeutics' MDMA-assisted therapy. Key clinical readouts remain pending, including REKINDLE topline results anticipated in 2027.