Definium Achieves Second Positive Phase 3 for GAD

NEW YORK – Definium Therapeutics Inc. released topline data from its second pivotal Phase 3 trial (Panorama study) of DT120 in generalized anxiety disorder (GAD), adding to earlier positive findings in the same indication and in major depressive disorder (MDD).

The trial evaluated a single dose of DT120, an orally disintegrating tablet formulation of lysergide (LSD) D-tartrate, against placebo in adults with DSM-5-confirmed GAD. According to the company’s press release, Panorama met its primary endpoint of change from baseline in Hamilton Anxiety Rating Scale (HAM-A) total score at Week 12. Participants receiving the 100 µg dose showed a least-squares mean improvement of 9.8 points, compared with 4.7 points for placebo, for a placebo-adjusted difference of 5.1 points. The standardized effect size was 0.64. Key secondary endpoints, including Clinical Global Impression-Severity (CGI-S) scores at Week 12 and Day 2 as well as the HAM-A change at Week 1, were also met. Benefits appeared as early as Day 2 and held through the 12-week double-blind period.

The study enrolled 245 participants aged 18 to 74 across roughly 32 U.S. centers, with randomization to 100 µg DT120, a 50 µg control arm, or placebo. The lower-dose arm was included to support blinding and was not powered for formal comparison; it produced a smaller placebo-adjusted change consistent with earlier dose-response observations. DT120 was generally well tolerated. Most treatment-emergent adverse events were mild to moderate, transient, and concentrated on dosing day. No new safety signals emerged, and discontinuation rates were similar across groups.

Panorama follows the positive Voyage Phase 3 results in GAD announced in August and the Emerge Phase 3 results in MDD reported in June. DT120 holds FDA Breakthrough Therapy designation for both indications. Definium has scheduled a pre-NDA meeting for Q4 2026 and anticipates a new drug application filing in H1 2027.

The consistent placebo-adjusted HAM-A separations across the two GAD trials, combined with rapid onset after a single administration and a manageable session profile, supply regulators and clinicians with a coherent data package in an indication that has seen limited new approvals for nearly two decades. The inclusion of the low-dose arm and the overall safety consistency strengthen the evidentiary foundation heading into regulatory discussions. Complete study reports and the forthcoming pre-NDA feedback will determine the precise path and timeline for potential review.