Definium Therapeutics Inc

We are a late-stage clinical biopharmaceutical company developing novel product candidates to treat brain health disorders. Our mission is to forge a new era of psychiatry by applying scientific rigor to psychedelics, with the goal of developing accessible treatments that unlock healing at scale. We are developing a pipeline of innovative product candidates targeting neurotransmitter pathways that play key roles in brain health disorders. This specifically includes pharmaceutically optimized product candidates derived from the psychedelic and empathogen drug classes including DT120 (previously referred to as MM120), and DT402 (previously referred to as MM402), our lead product candidates.

Our first lead product candidate, DT120 ODT, is a proprietary, pharmaceutically optimized form of lysergide D-tartrate that we are developing for the treatment of adults with generalized anxiety disorder and major depressive disorder. In December 2023, we announced positive topline results from our Phase 2b clinical trial of DT120 for the treatment of GAD. The trial met its primary endpoint, with DT120 demonstrating statistically significant and clinically meaningful dose-dependent improvements on the Hamilton Anxiety Rating Scale ("HAM-A") compared to placebo at Week 4. In March 2024, we announced that the U.S. Food and Drug Administration ("FDA") granted breakthrough designation to our DT120 program for the treatment of GAD. We also announced in March 2024 that our Phase 2b clinical trial of DT120 in GAD met its key secondary endpoint, and 12-week topline data demonstrated clinically and statistically significant durability of activity observed through Week 12. In September 2025, we announced that the full results from our Phase 2b clinical trial of DT120 in GAD had been published in the Journal of the American Medical Association.

In June 2024, we announced the completion of our End-of-Phase 2 meeting with the FDA, supporting the advancement of DT120 into pivotal trials for the treatment of adults with GAD. Our Phase 3 clinical program for DT120 ODT is expected to consist of two clinical trials: the Voyage study (DT120-300) and the Panorama study (DT120-301). Both trials are comprised of two parts: Part A, which is a 12-week, randomized, double-blind, placebo-controlled, parallel-group trial assessing the efficacy and safety of DT120 ODT versus placebo; and Part B, which is a 40-week extension period during which participants will be eligible for open-label treatment with DT120 ODT, subject to certain conditions for treatment eligibility. Voyage is anticipated to enroll approximately 200 participants (randomized 1:1 to receive DT120 ODT 100 g or placebo) and Panorama is anticipated to enroll approximately 250 participants (randomized 2:1:2 to receive DT120 ODT 100 g, DT120 ODT 50 g or placebo). Both trials use an adaptive trial design with a blinded interim sample size re-estimation ("SSRE"), allowing for an increase in sample size by up to 50% in each trial depending on the observed values for certain nuisance parameters. The SSRE for Voyage has been completed and it was determined that no increase in the sample size of the trial is required. The primary endpoint for each trial is the change from baseline in HAM-A score at Week 12 between DT120 ODT 100 g and placebo. In December 2024, we announced the initiation of Voyage, and we anticipate a topline readout (Part A results) in early third quarter 2026. In January 2025, we announced the initiation of Panorama, with an anticipated topline readout (Part A results) in the second half of 2026.

In addition to our Phase 3 clinical program for GAD, we are developing DT120 ODT for the treatment of adults with MDD. In the first quarter of 2024, we held a pre-IND meeting with FDA to discuss the initiation of our Phase 3 clinical program for DT120 ODT in MDD and the trial design for the Emerge study (DT120-310), which like our pivotal trials in GAD, we anticipate will be comprised of two parts: Part A, which is a 12-week, randomized, double-blind, placebo-controlled, parallel group trial assessing the efficacy and safety of DT120 ODT versus placebo; and Part B, which is a 40-week extension period during which participants will be eligible for open-label treatment with DT120 ODT, subject to certain conditions for treatment eligibility. Emerge is fully enrolled with 149 participants randomized 1:1 to receive DT120 ODT 100 g or placebo. The primary endpoint is the change from baseline in Montgomery sberg Depression Rating Scale ("MADRS") score at Week 6 between DT120 ODT 100 g and placebo. In April 2025, we announced the initiation of Emerge, and we anticipate a topline readout (Part A results) in late second quarter 2026.