MM120 (lysergide D-tartrate)

May 12, 2026 — Definium Therapeutics, Inc. (Nasdaq: DFTX) announced the first patient dosed in Ascend, its second Phase 3 pivotal trial evaluating DT120 Orally Disintegrating Tablet (ODT; lysergide tartrate, a proprietary LSD formulation) for major depressive disorder (MDD). The U.S. study is expected to enroll 175 participants and compares DT120 ODT vs placebo.

Ascend has two parts: Part A is a 12-week randomized, double-blind, placebo-controlled, parallel-group period; Part B is a 40-week open-label extension based on symptom severity. Participants are randomized 2:1:2 to DT120 ODT 100 µg, DT120 ODT 50 µg, or placebo; the 50 µg arm is intended to reduce dose-guessing (“functional unblinding”). The primary endpoint is change from baseline in MADRS at Week 6 for 100 µg vs placebo.

The company said Ascend builds on positive Phase 2b results in generalized anxiety disorder that suggested potential antidepressant effects. Topline data from Part A are anticipated in 2027, positioning Ascend as a key late-stage efficacy/safety readout in Definium’s MDD program.