Definium’s Psychedelic Anxiety Drug DT120 Moves Closer to the Mainstream With a Phase 3 Win

Definium Therapeutics reported positive Phase 3 results for DT120, its LSD-based treatment for generalized anxiety disorder, marking the drug’s second late-stage clinical success in less than two months. A single 100-microgram dose significantly reduced anxiety symptoms compared with placebo in the 214-patient Voyage trial, with benefits emerging within two days and continuing through Week 12.

The results strengthen Definium’s late-stage program across anxiety and major depressive disorder as the company prepares additional Phase 3 data and evaluates a potential regulatory path. DT120 remains investigational, and the company must complete further trials and secure FDA approval before the treatment can reach patients.

The Voyage Trial, By the Numbers

Definium Therapeutics said Wednesday that DT120, its lysergide-based orally disintegrating tablet, met the primary endpoint of Voyage, a Phase 3 trial in generalized anxiety disorder, the company announced. Participants who received a single 100-microgram dose saw their Hamilton Anxiety Rating Scale score fall by 11.6 points from baseline at Week 12, versus 6.2 points for placebo — a placebo-adjusted difference of 5.4 points. The 214-patient trial also cleared its key secondary endpoints: 43% of DT120 patients achieved at least a 50% improvement in symptoms, compared with 16% on placebo, and 14% reached remission versus 4% on placebo. Improvements were detectable within two days of dosing and held through the full 12-week assessment period.

A Second Win Follows a First in Depression

Voyage is Definium’s second positive Phase 3 readout this summer. In June, the company reported that Emerge, a 149-patient trial of the same DT120 dose in major depressive disorder, produced an 8.1-point placebo-adjusted improvement on the Montgomery-Åsberg Depression Rating Scale at Week 6, with the effect still measurable at Week 12, according to Definium’s own release. Both trials tested a single dose rather than a repeated regimen, a structural feature the company has positioned as a practical advantage over daily antidepressants and clinic-based treatments that require repeat visits.

Definium Chief Executive Rob Barrow called the anxiety improvement “a sea change” in patients’ treatment prospects, noting the company had never before seen a pivotal study top a five-point placebo-adjusted change on this scale.

The results also provide context for the drug’s potential commercial scale. Leerink Partners neuroscience analyst Marc Goodman previously estimated peak sales of $1.5 billion to $2 billion for the major depressive disorder indication alone. While such forecasts remain subject to regulatory approval, market access, and clinical adoption, the estimate illustrates the commercial opportunity already associated with the program before its potential expansion into anxiety and other psychiatric indications.

Definium, listed on Nasdaq under the ticker DFTX, was formerly known as MindMed before rebranding around its lead compound. The company reported roughly $1.1 billion in cash, cash equivalents, and investments as of June 30, giving it runway to fund its remaining late-stage trials without an immediate need to raise capital, according to its second-quarter results. DT120 is formulated as an orally disintegrating tablet of lysergide — the exact chemical name for LSD — designed to deliver a standardized, reproducible dose rather than the variable-potency products associated with illicit use.

What’s Next: More Data and a Regulatory Path

Definium’s second pivotal Phase 3 trial in generalized anxiety disorder, Panorama (NCT06809595), is expected to report topline results in September 2026. The study enrolled 245 participants across the United States and Europe, randomized to receive DT120 ODT at 100 µg, a 50 µg active-control dose, or placebo. The lower-dose arm is intended to reduce the risk of functional unblinding—a particular challenge in psychedelic trials because participants may recognize the drug’s psychoactive effects. Results from Panorama will complement those from Voyage (NCT06741228), providing evidence from two pivotal studies of DT120 ODT in generalized anxiety disorder.

The company is also enrolling participants in Ascend (NCT07592689), its second Phase 3 trial in major depressive disorder, with topline data expected in 2027. Ascend will assess changes in depression severity at Week 6 and, like Panorama, includes a 50 µg active-control arm alongside the 100 µg dose and placebo. Beyond depression and anxiety, Definium plans to initiate Haven, a Phase 3 PTSD study, in 2027; the proposed trial would enroll approximately 200 participants and measure PTSD symptoms at Week 8. No ClinicalTrials.gov identifier has yet been published for Haven, and Definium has not announced a target date for an FDA submission. However, the growing Phase 3 dataset across multiple indications is expected to inform the company’s eventual regulatory strategy for DT120 ODT, and executives have described their regulatory dialogue as constructive.

Regulatory Landscape: DEA Scheduling Still Looms

Even a successful FDA review would not be the final hurdle. LSD remains a Schedule I controlled substance under federal law, meaning the Drug Enforcement Administration would need to reschedule it before DT120 could be prescribed commercially — a step that has trailed FDA decisions for other psychedelic-derived medicines in development. Compass Pathways, whose psilocybin candidate is further along in a separate rolling FDA submission, has flagged the same rescheduling requirement as a condition of its own planned 2027 launch, the company has said.

Where Definium Fits in a Broader Resurgence

Definium’s back-to-back Phase 3 wins land amid a broader run of pharmaceutical investment in psychedelic-derived medicines, including Eli Lilly’s $2.8 billion acquisition of AtaiBeckley in July and AbbVie’s earlier deal for Gilgamesh Pharmaceuticals’ bretisilocin program. Each company is betting on a different molecule and a different indication, but all are chasing the same premise Definium’s data appears to support: that a carefully dosed, single-administration psychedelic compound can produce effects that outlast anything currently on the market.

Author

Bernice Lottering

Related Post

Trials & Approvals

Tokyo’s Taiho and Cullinan Announce Positive Phase 3 Lung Cancer Results

2026-08-20

Neuroscience & Mental Health

Breakthrough or Bubble? The High-Stakes 2026 Readouts for Psychedelic Giants

2026-01-27

go prime

New Combo Therapy Shows Major Survival Gains in Cisplatin-Ineligible Bladder Cancer

2025-08-13