Reunion Neuroscience Secures $103M Series A Funding Co-Led by MPM BioImpact and Novo Holdings

Reunion Neuroscience Inc., a clinical-stage biopharmaceutical company dedicated to advancing neuroscience, has successfully closed a $103 million Series A financing round. The round was co-led by major institutional investors MPM BioImpact and Novo Holdings, with additional support from Arkin Bio Capital, Mitsui & Co. Global Investment, Plaisance Capital, FemHealth Ventures, and Palo Santo. This substantial financial boost will be pivotal in advancing the company’s innovative research and development programs.

The President and CEO of Reunion, Greg Mayes, expressed gratitude for the support from these top-tier healthcare investors. He emphasized the potential of Reunion Neuroscience to revolutionize mental health treatment and address the global mental health crisis. The financing will primarily support the clinical advancement of their leading drug candidate, RE104, in treating postpartum depression (PPD) and other psychiatric disorders with high unmet needs, such as adjustment disorder in cancer (ADC).

Dr. Ansbert Gadicke, Managing Partner at MPM BioImpact, praised Reunion’s efforts to transform the treatment landscape for severe mental health disorders. He noted the potential of RE104 to deliver meaningful and long-lasting antidepressant effects. Similarly, Dr. Natalie Sacks from Novo Holdings highlighted the promise of RE104 as a best-in-class therapy that could significantly improve outcomes for patients with limited treatment options in PPD and other mental health conditions.

Reunion Neuroscience's flagship asset, RE104, is a proprietary, patented prodrug of 4-OH-DiPT designed to target the serotonin 2A receptor, which is crucial for the antidepressant effects of psychedelic compounds. According to recent FDA guidelines, such drugs necessitate supervision by trained healthcare professionals. RE104 is engineered to provide a short-duration psychedelic experience, requiring only about half a day in a clinical setting, unlike other psychedelics like psilocybin and MDMA that require longer durations.

In a Phase 1 study, RE104 demonstrated a psychoactive state similar in intensity to psilocybin but with a shorter duration of 3-4 hours and a favorable safety profile. The company plans to begin patient enrollment for the RECONNECT Trial, a Phase 2 study evaluating RE104 in moderate to severe PPD patients, with results anticipated by the second quarter of 2025. PPD is a severe form of major depression affecting 10-15% of new mothers and is a leading cause of pregnancy-related deaths due to mental health conditions such as suicide and substance use disorder.

RE104 aims to address the significant unmet need in PPD treatment by offering improved safety, faster onset of action, greater efficacy after a single dose, minimal breastfeeding interruption, and a quicker return to daily activities. Beyond PPD, Reunion is exploring the use of RE104 in other neuropsychiatric conditions, including adjustment disorder in cancer (ADC), characterized by a maladaptive response to a cancer diagnosis that persists beyond two weeks. This disorder affects about 40% of cancer patients by inducing mood disorders.

Reunion Neuroscience, as part of MPM BioImpact’s portfolio, continues to push the boundaries of neuroscience to develop groundbreaking therapeutic solutions for PPD and other underserved mental health disorders. The company's commitment to innovation is evident in its development of RE104, which holds promise for rapid symptom relief and lasting efficacy across multiple psychiatric indications.