Definium Therapeutics

Definium Therapeutics (operating at definiumtx.com) is a clinical biopharmaceutical company engineered for developing novel product candidates to treat brain health disorders. Founded in 2019 by Jamon "JR" Rahn, Stephen Hurst, and Scott Freeman and headquartered in New York, Definium Therapeutics is forging a new era in psychiatry by harnessing the full therapeutic potential of psychedelic medicine. Under the hood, the company is applying precision to psychedelic medicine. This allows researchers and patients to explore new treatment options for brain health disorders. Backed by a $259 million equity financing in 4Q 2025.