Definium Therapeutics announced on June 22, 2026, that its Phase 3 EMERGE study of DT120 orally disintegrating tablet, a proprietary formulation of lysergide (LSD) dosed at 100 micrograms, met its primary endpoint in adults with major depressive disorder. The results place DT120 among the most closely watched CNS readouts of 2026 and add meaningful Phase 3 evidence to the nascent psychedelic-adjacent medicine category.

The EMERGE study was a randomised, double-blind, placebo-controlled trial in adults with MDD. The primary endpoint was the change from baseline in Montgomery-Asberg Depression Rating Scale (MADRS) total score at Week 6 following a single administration of DT120. Participants who received the active treatment showed a least-squares mean change of -13.3 points, compared with -5.2 points for those on placebo, a least-squares mean difference of -8.1 points (p<0.0001). By conventional interpretation, an MADRS reduction of 8 points is considered clinically meaningful, and the placebo-adjusted effect size here comfortably exceeds that threshold. What is particularly notable is the speed of onset. A placebo-adjusted reduction of -14.2 MADRS points was observed at Week 1 (p<0.0001), suggesting antidepressant activity that materially outpaces conventional selective serotonin reuptake inhibitors, which typically require two to six weeks to demonstrate clinical effect. Sustained separation from placebo was evident at Week 12 with a reduction of -7.3 points (p<0.0001), indicating that a single-dose regimen produces effects that extend well beyond the acute pharmacological window. DT120 had no serious adverse events reported in EMERGE and no suicidality signal, a finding that will carry weight with the FDA given the black-box warning landscape for psychiatric medications in younger patient populations. The oral disintegrating tablet format is a deliberate design choice aimed at improving dosing convenience and potentially supporting supervised outpatient administration models, distinct from intravenous ketamine or psilocybin protocols that require clinic attendance. MDD remains one of the most prevalent and disabling conditions globally, affecting an estimated 280 million people. Existing pharmacotherapy, while effective in many patients, leaves a substantial proportion without adequate response after one or more treatment trials. The treatment-resistant MDD population, in particular, has driven substantial clinical and investor interest in rapid-acting mechanisms, including glutamatergic compounds such as esketamine and, now, lysergide derivatives. The EMERGE results build a scientific foundation for a future FDA submission, though the regulatory pathway for lysergide-based medicines remains novel. Definium will present full data and is expected to discuss its NDA strategy and the schedule for potential confirmatory studies in coming months.