Definium’s LSD-Based DT120 ODT Delivers Landmark Phase 3 Victory in Major Depressive Disorder
On June 22, 2026, Definium Therapeutics (formerly MindMed) announced positive topline results from its pivotal Phase 3 Emerge trial (NCT06941844) evaluating DT120 ODT (orally disintegrating tablet), a proprietary formulation of lysergide (LSD), in patients with Major Depressive Disorder (MDD). The 149-patient study met its primary and key secondary endpoints with statistical significance, demonstrating some of the most robust efficacy data seen in depression clinical trials to date.
At the 6-week primary endpoint, patients treated with a single 100µg dose of DT120 ODT experienced an 8.1-point placebo-adjusted reduction in symptom severity on the Montgomery-Åsberg Depression Rating Scale (MADRS). At 12 weeks, the therapeutic effect remained highly durable, showing a 7.1-point placebo-adjusted reduction on the MADRS. The drug was well tolerated with no new safety signals and no evidence of increased suicidal ideation or behavior.
Definium’s Chief Medical Officer, Daniel Karlin, M.D., highlighted the choice of molecule:
"We have every reason to think that LSD specifically is the best drug in the category... remarkably potent and uniquely gentle when exerting its effects."
The trial's design required patients to be monitored by a trained chaperone for an 8-hour session to provide a "grounding force," but deliberately omitted active psychological interventions to isolate the drug's biological effect.
This breakthrough comes amid intense political focus on psychedelic medicine. In April 2026, President Trump signed an executive order instructing the FDA to grant priority review vouchers to psychedelic drug developers. While competitors like Compass Pathways and the Usona Institute secured vouchers, Definium did not. However, company leadership expressed relief at avoiding the political fray, with Dr. Karlin stating:
"What we don't want is an approval that has a political flavor to it. The last thing we'd want is for anybody to think that we got shortcuts or that our review and approval was unscientific in some way."
Definium is currently running two Phase 3 trials in generalized anxiety disorder (GAD) and a low-dose Phase 3 depression trial, with additional readouts expected by the end of 2026.