Definium's LSD-Based Psychedelic DT120 ODT Achieves Second Phase 3 Victory in Generalized Anxiety Disorder

Definium's LSD-Based Psychedelic DT120 ODT Achieves Second Phase 3 Victory in Generalized Anxiety Disorder

Definium Therapeutics (formerly MindMed) has announced highly positive topline results from its Phase 3 Voyage study evaluating DT120 (lysergide tartrate) Orally Disintegrating Tablet (ODT) in adults with generalized anxiety disorder (GAD). This represents the second major clinical victory for the company's proprietary formulation of LSD, following a positive Phase 3 Emerge readout in major depressive disorder (MDD) in June 2026.

Highly Significant and Rapid Anxiety Reductions

The Phase 3 Voyage study evaluated a single 100 µg dose of DT120 ODT against placebo in 214 adults with moderate-to-severe GAD over a 12-week double-blind period (Part A). The trial met its primary and all key secondary endpoints with high statistical significance:

• Primary Endpoint: At Week 12, patients treated with a single dose of DT120 ODT achieved a statistically significant and clinically meaningful reduction in Hamilton Anxiety Rating Scale (HAM-A) total score, showing a placebo-adjusted change of 5.4 points from baseline ($p < 0.0001$, Cohen's $d = 0.81$).
• Rapid Onset: Efficacy emerged as early as Day 2, demonstrating a placebo-adjusted improvement of 0.8 points on the Clinical Global Impression-Severity (CGI-S) scale ($p < 0.0001$), and was sustained at all post-baseline timepoints.
• Response and Remission: At Week 12, the HAM-A response rate (defined as $\ge 50%$ improvement) was 43% for DT120 ODT vs. 16% for placebo ($p < 0.0001$). The clinical remission rate (HAM-A $\le 7$) was 14% for DT120 ODT vs. 4% for placebo ($p = 0.0222$).

Favorable Safety Profile and Clinical Session Predictability

Unlike traditional GAD treatments that require daily dosing and long-term maintenance, DT120 ODT is designed as a single-dose intervention with a rapid and predictable clinical session profile¹, which is highly advantageous for clinical adoption²:

• Tolerability: DT120 ODT was generally well tolerated. Most treatment-emergent adverse events (TEAEs) were mild-to-moderate, transient, and occurred primarily on the day of dosing. The most common TEAEs included illusions (75% on dosing day vs. 0% for placebo) and nausea (38% on dosing day vs. 3% for placebo).
• No Suicidality Signal: Crucially, there were no serious adverse events (SAEs) reported in the active treatment arm, and no suicidality signals or suicidal behaviors were observed.
• Session Predictability: The average time for patients to clear the End of Session Checklist (EoSC) was 6.4 hours, with 92% of participants clearing the checklist by Hour 8, providing strong evidence of predictable 5-to-8-hour clinical sessions.

Clinical and Regulatory Context

Generalized anxiety disorder affects approximately 26 million adults in the United States and has seen virtually no pharmacological innovation since the last drug approval in 2007. Having received FDA Breakthrough Therapy designation for GAD, Definium is advancing DT120 ODT toward a potential regulatory filing. The company is currently conducting its second Phase 3 GAD trial, Panorama, which includes a low-dose 50 µg arm to confound functional unblinding. Topline data from the Panorama trial are expected in September 2026.

"The unprecedented efficacy demonstrated in Voyage should raise the bar for what patients and clinicians expect from GAD treatments and reinforces our belief that DT120 has the potential to redefine care for the millions of patients in need." — Rob Barrow, Chief Executive Officer of Definium Therapeutics

"A single-dose treatment option delivering meaningful benefits for 12 weeks is a promising step forward not found in today’s therapies. If approved, it could give patients and their physicians a treatment option that works through an entirely different mechanism than anything currently used in clinical practice." — Brian Barnett, MD, Vice Chair of Psychiatry at Cleveland Clinic, and a Voyage principal investigator