Definium's LSD-Based Therapy Beats Analyst Expectations in Phase 3 Anxiety Trial

Definium Therapeutics' single-dose oral LSD candidate DT120 significantly reduced anxiety symptoms compared with placebo in a highly anticipated Phase 3 study, the company said Wednesday — its second late-stage win this summer and a result that beat Wall Street expectations, BioSpace reported.

The Voyage Results

The 12-week Voyage trial enrolled 214 adults with generalized anxiety disorder. Participants receiving DT120, also called lysergide tartrate, experienced a statistically significant placebo-adjusted reduction of 5.4 points from baseline on a clinician-administered anxiety scale, with p < 0.0001 — ahead of the 5-point drop analysts had projected. Jefferies wrote that the drug has shown one of the strongest placebo-adjusted efficacy benefits in GAD, while Stifel dubbed the data a clean win. No serious adverse events occurred, most patients were ready for discharge after six hours, and no suicidality signal was recorded.

Building on the MDD Win

The results follow a separate Phase 3 success for DT120 in major depressive disorder reported in June, which saw an 8.1-point placebo-adjusted change over six weeks, also exceeding analyst expectations. The efficacy is slightly below the Phase 2b GAD finding of a 7.7-point reduction, which analysts said was expected given the larger patient population. Definium is moving DT120 into a 40-week extension phase and awaiting a second GAD study, Panorama, with a readout due next month; success there would position the company to file a new drug application likely in the first half of next year, Stifel wrote.

The drug has secured FDA Breakthrough Therapy designation in GAD, and Jefferies has modeled at least $1.5 billion in peak sales for the indication. DT120 is also being developed for post-traumatic stress disorder, with a late-stage trial slated to launch next year — as Compass Pathways advances a psilocybin program through a rolling FDA filing.