Definium's LSD candidate receives a second FDA Breakthrough Therapy designation for major depressive disorder

Definium Therapeutics' LSD candidate DT120 received its second FDA Breakthrough Therapy designation, this time for major depressive disorder, after previously receiving the status for generalized anxiety disorder in 2024. The MDD designation is supported by the Phase 3 Emerge trial, which reported an 8.1-point placebo-adjusted improvement on a standard depression scale at six weeks, with a 7.3-point advantage remaining at week 12. Breakthrough Therapy status can provide closer FDA interaction, trial-design guidance, and flexible application submission, but it does not guarantee approval or shorten the formal review clock. The piece contrasts this development-stage advantage with the post-submission acceleration offered by priority vouchers held by Compass Pathways and Usona. It also notes that the evidence remains preliminary, company-reported results are not yet fully peer reviewed, and no drug in this class has completed approval.