A Phase 2A Trial of MM402 for Autism Spectrum Disorder

This Phase II, open-label trial (n=20) will evaluate the effects of a single administration of MM402, the R-enantiomer of MDMA, in adults aged 18 to 45 with Autism Spectrum Disorder (ASD). The primary aim is to assess changes in social responsiveness and communication deficits, as measured by an 11-point Numerical Rating Scale (NRS) at various time points post-dose. The study will include approximately twenty participants diagnosed with ASD who exhibit clinically significant deficits in socialisation and communication. Participants will receive a single dose of 200 mg MM402, with assessments occurring at baseline, pre-dose, and at 2, 4, 6, 8, and 24 hours post-dose, as well as on day 15. The trial will exclude individuals with certain eye movement abnormalities, a history of psychotic or bipolar disorders, current substance use disorders, or any clinically significant unstable illness. The study is sponsored by Definium Therapeutics US, Inc., with an estimated start date in December 2025 and completion anticipated by August 2027.