Definium Therapeutics Inc. presented Phase III clinical trial results for DT120, a psychedelic-derived drug candidate, at the TD Cowen 6th Annual Novel Mechanisms in Neuropsychiatry Summit on September 23, 2026. The drug is being evaluated for generalized anxiety disorder (GAD) and major depressive disorder (MDD), both carrying FDA breakthrough designations. DT120 demonstrated statistically significant improvements across three studies conducted over a 10-week primary observation period in summer 2024, with no adjunctive psychotherapy or medication allowed during the initial phases.
In the GAD trials, VOYAGE and PANORAMA, patients averaged severe baseline scores on the Hamilton Anxiety Rating Scale (HAM-A) of around 28. DT120 produced a 5.4-point reduction in VOYAGE and a 5.1-point reduction in PANORAMA versus placebo, with p-values below 0.0001. Response rates were 43% and 32% respectively, while remission rates were 14% and 15%. The MDD study, EMERGE, showed an 8.1-point improvement on the Montgomery-Åsberg Depression Rating Scale (MADRS) versus placebo, with a p-value under 0.0001, yielding a 43% response rate and 20% remission rate at week 12. Odds ratios for response and remission ranged from nearly 4 to 2.5–4.
The trials expanded into Part B extensions, extending observations for up to 40 weeks with open-label treatment opportunities, allowing for retreatment if patients reached moderate severity thresholds (MADRS 20 or HAM-A 16). In the initial open-label phase, remission rates converged toward 60%–70% with repeated dosing, with patients typically receiving 1–3 treatments over six months, no more than monthly, and a maximum of five treatments annually. Safety metrics indicated rapid clearance—median and mean times around six hours, with 97% of patients cleared by hour eight—and a quick assessment of decision-making capacity taking under a minute.
Definium is engaged in ongoing discussions with the FDA’s Division of Psychiatry, covering clinical pharmacology, safety, and manufacturing controls. A pre-NDA meeting is planned to determine whether to submit applications for GAD and MDD simultaneously, sequentially, or overlapping. The company is also evaluating commercial distribution models, including buy-and-bill and white-bagging, which currently split the SPRAVATO market evenly.
The data underscore DT120’s potential as a standalone treatment for GAD and MDD, with Phase II precedent showing nearly 50% remission rates, though further regulatory and commercial validation remains necessary.
