Definium Therapeutics, Inc., a clinical biopharmaceutical company, develops novel product candidates to treat brain health disorders. The company's lead product candidates DT120, which is in phase 3 for the treatment of generalized anxiety disorder, major depressive disorder, and other brain health disorders; and DT402, a R-enantiomer of 3,4-methylenedioxymethamphetamine, which is in phase 2a clinical trials for the treatment of autism spectrum disorder. The company was formerly known as Mind Medicine (MindMed) Inc. and changed its name to Definium Therapeutics, Inc. in January 2026. Definium Therapeutics, Inc. is headquartered in New York, New York.