MM120 · program
Lysergide D-tartrate (MM120 / LSD) for Post-traumatic stress disorder
Indications for MM120: Generalized anxiety disorder · Phase 3 Attention-deficit/hyperactivity disorder · Discontinued Major depressive disorder · Phase 3 Post-traumatic stress disorder · Phase 3
DT120 ODT (formerly MM120; lysergide D-tartrate / LSD) for posttraumatic stress disorder (PTSD) - the third indication after the lead GAD program (Voyage/Panorama) and MDD (Emerge/Ascend). Announced at Definium Therapeutics' April 22, 2026 Investor & Analyst Day as a planned Phase 3 study named 'Haven': ~200 participants randomized 1:1 to a single dose of DT120 ODT vs placebo, primary endpoint change in Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) at Week 8, study initiation expected in 2027. Not yet registered on ClinicalTrials.gov.
Development timeline
- Definium Therapeutics announced expansion of the DT120 ODT program into PTSD with the planned Phase 3 'Haven' study (~200 participants, 1:1 DT120 ODT vs placebo, primary endpoint CAPS-5 at Week 8), initiation expected in 2027. No NCT registered as of this record.↗
Readouts
- 2027AnticipatedRegistry results
Phase 3 Haven study of DT120 ODT in PTSD expected to initiate in 2027 ↗
Mechanism of action
LSD acts across serotonin receptor subtypes; the company describes MM120 as a 5-HT2A partial agonist (IUPHAR classifies LSD as a full 5-HT2A agonist). Antidepressant effects attributed primarily to 5-HT2A agonism.
| Target | Action | Affinity |
|---|---|---|
| 5-HT2AprimaryHTR2A | Partial agonist | pKi 9.4ⓘ |
| 5-HT1AHTR1A | Agonist | pKi 9ⓘ |
| 5-HT2CHTR2C | Agonist | pKi 8.2ⓘ |
← Full MM120 compound page (identity, identifiers, all indications)