Definium Therapeutics has reported another successful Phase 3 trial for DT120, its LSD-based orally disintegrating tablet for generalized anxiety disorder. The Panorama study met its primary endpoint and all key secondary efficacy endpoints, giving the company a second positive Phase 3 result in anxiety and a third positive late-stage result for DT120 overall. Definium is now preparing for a pre-New Drug Application meeting with the US Food and Drug Administration in the fourth quarter of 2026, with an NDA filing planned for the first half of 2027.
Panorama enrolled 245 adults with generalized anxiety disorder across roughly 32 study sites. Participants were randomized to receive a single 100-microgram dose of DT120, a 50-microgram dose or placebo, with the lower-dose arm included partly to address concerns about functional unblinding in psychedelic trials. The main comparison showed that patients receiving 100 micrograms improved by 9.8 points on the Hamilton Anxiety Rating Scale after 12 weeks, compared with a 4.7-point reduction for placebo.
That produced a placebo-adjusted difference of 5.1 points, which was statistically significant with a p-value below 0.0001 and an effect size of 0.64. Definium also reported that benefits were detectable as early as Day 2 and remained present across the measured timepoints during the 12-week double-blind portion of the study. The trial met key secondary measures including improvement on the Clinical Global Impression-Severity scale at Week 12 and Day 2, as well as HAM-A improvement at Week 1.
Response and remission measures also favored the higher dose. At Week 12, 32% of patients in the 100-microgram group achieved at least a 50% reduction in HAM-A scores compared with 14% of placebo patients, while 15% met the study’s remission threshold compared with 4% on placebo. Definium said 35% of treated patients reached a mild-or-better anxiety score, versus 17% in the placebo arm.
The study also included 52 participants who received 50 micrograms of DT120, although Definium says that arm was not powered for formal statistical comparisons. The lower dose produced a smaller placebo-adjusted improvement than the 100-microgram dose, supporting the company’s argument that the stronger therapeutic effect is dose-related rather than simply a consequence of participants recognizing that they received a psychoactive drug. Functional unblinding has become a significant regulatory concern in psychedelic trials because subjective drug effects can make it difficult to maintain a truly blinded study.
Safety results were broadly consistent with earlier DT120 studies, according to Definium. Most treatment-emergent adverse events were mild to moderate, temporary and concentrated on the dosing day, with illusion, nausea and headache among the most frequently reported events. The company reported no new safety signals, no suicidality signal and no drug-related serious adverse events.
DT120 is administered as a single supervised dose rather than a daily medication. Participants remained under observation for at least eight hours after dosing, with Definium reporting that 94% of patients receiving the 100-microgram dose met discharge criteria within that period. Across more than 1,000 Phase 3 treatment sessions conducted through September 10, the company says 97% of participants met those criteria by eight hours.
Panorama follows the positive Voyage Phase 3 study in generalized anxiety disorder announced in August. That trial produced a similar placebo-adjusted improvement on the HAM-A scale, strengthening Definium’s case that the effect can be reproduced across separate late-stage studies. The company also reported positive Phase 3 results from its Emerge trial in major depressive disorder in June, meaning DT120 has now produced three successful pivotal readouts across the two indications.
Definium is seeking to position DT120 for both generalized anxiety disorder and major depressive disorder. The FDA granted the therapy Breakthrough Therapy designation for major depressive disorder earlier in September, and the company still has another Phase 3 depression study underway. Management says the upcoming pre-NDA meeting will help determine the filing strategy and sequence for the two indications.
The latest data move DT120 closer to a possible regulatory submission, but the treatment is not yet FDA-approved and the Panorama results remain topline findings rather than a completed regulatory review. Definium currently expects to file an NDA in the first half of 2027 after discussing the Phase 3 package with the FDA later this year.
