Precise science. Boundless impact.
Forging a New Era of Psychiatry
We believe progress shouldn’t inch ahead, it should leap forward.
We Measure Progress by the Lives We Transform
Guided by precision and scientific rigor, we are harnessing the full therapeutic potential of psychedelic medicine to develop accessible treatments that unlock healing at scale.
Redefining what treatment means for brain health disorders
Millions living with anxiety, depression and posttraumatic stress disorder (PTSD) have been stuck with a status quo that, for too long, has simply not worked for them. There’s broad recognition that today’s treatments fall short of what patients need and that those who suffer are out of options.
From day one, we have been powered by a radical idea: treatments for brain health disorders should bring real relief. Today, we are making that idea a reality. We are opening new routes for brain health by retracing LSD to its origins and unlocking its clinical promise as a transformative therapeutic. Our science is turning evidence into impact, serving as a catalyst that can help people renew their sense of self and reclaim more vibrant lives.
Moving psychiatry forward – beyond better, into a boundless future
Fueled by our combined decades of expertise at the forefront of biotech, our vision is to drive healing at scale. Whether we are advancing new molecules or building new partnerships, we measure progress by the lives we transform.
DT120 ODT
DT120 orally disintegrating tablet (ODT) is our proprietary and pharmaceutically optimized formulation of lysergide (LSD) D-tartrate. DT120 ODT increases connections between areas of the brain that aren’t normally connected, enabling changes that could treat depression, anxiety, PTSD, and other health disorders.
DT402
DT402 is the R-enantiomer of MDMA (R(-)-MDMA), selected for its serotonergic properties. In preclinical studies, DT402 has shown promising prosocial effects with a potentially superior tolerability profile compared to both racemic MDMA and the S-enantiomer.1 DT402 is being developed to target the core symptoms of autism spectrum disorder, specifically addressing social communication challenges.
Making healing possible for those who need more than better
GAD is a chronic, debilitating disorder characterized by excessive anxiety and worry lasting for 6 months or more. Patients with GAD find it difficult to control the worry, often resulting in impairment in social, occupational, or other areas of functioning.2
MDD is characterized by the presentation of five or more depressive symptoms, occurring for at least 2 weeks and can include feelings of worthlessness, fatigue, impaired social functioning, and recurrent thoughts of death.3
PTSD is a mental health disorder that can develop after experiencing or witnessing a traumatic event, including violence, accidents, or natural disasters. PTSD manifests as intrusive memories, negative changes in mood or thinking, and heightened reactions that may last for months or years and disrupt daily life.4 The majority of veterans diagnosed with PTSD also have a comorbid depressive or anxiety disorder.5
Approximately 5.4M people in the U.S. live with ASD.6 There are no drugs approved to treat the core symptoms, which include communication and social interaction challenges.
Adults in the U.S. living with GAD7,8
26M
Adults in the U.S. living with MDD7
41M
Adults in the U.S. experiencing PTSD annually9
11M
Adults in the U.S. living with ASD6
5.4M
Research & Development Pipeline
Our pipeline offers opportunities across diverse therapeutic areas and mechanisms of action.
- Formerly known as MM120; rINN: lysergide tartrate.
- Formerly known as MM402.
- Full trial details and clinicaltrials.gov links available on https://www.definiumtx.com/clinical-trials/.
- Studies in exploration and/or planning stage.
R(-)-MDMA: rectus-3,4-methylenedioxymethamphetamine
The Latest News
Precise science.
Boundless impact.
- “MM402 demonstrates better efficacy than S(+)-3,4-MDMA or (+/-)-MDMA in Fmr1 knockout mice, an animal model of autism spectrum disorder.” Presented at ECNP 2023. Data from “stranger” portion of “Duration in the arena” data.
- Ringeisen, H., et al. (2023). Mental and Substance Use Disorders Prevalence Study (MDPS): Findings Report. RTI International.
- APA. Diagnostic and statistical manual of mental disorders: DSM-5-TR. Fifth edition, text revision. ed. Washington, DC: American Psychiatric Association Publishing; 2022.
- National Institute of Mental Health. (2023). Post-traumatic stress disorder. U.S. Department of Health and Human Services, National Institutes of Health. https://www.nimh.nih.gov/health/publications/post-traumatic-stress-disorder-ptsd
- Trivedi RB, Post EP, et al. Prevalence, Comorbidity, and Prognosis of Mental Health Among US Veterans. Am J Public Health. 2015 Dec;105(12):2564-9.
- Dietz PM, Rose CE, McArthur D, Maenner M. National and State Estimates of Adults with Autism Spectrum Disorder. J Autism Dev Disord. 2020;50(12):4258-4266.
- Ringeisen, H., et al. (2023). Mental and Substance Use Disorders Prevalence Study (MDPS): Findings Report. RTI International and current U.S. Census data and internal company estimates.
- Ferries, E., et al. The Prevalence and Burden of Generalized Anxiety Disorder in the United States Healthcare System: Real-World Prevalence and Incidence from 2020-2023. Journal of Mood and Anxiety Disorders. 2026;13.
- Goldstein RB, et al. The epidemiology of DSM-5 posttraumatic stress disorder in the United States: results from the National Epidemiologic Survey on Alcohol and Related Conditions-III. Soc Psychiatry Psychiatr Epidemiol. 2016 Aug;51(8):1137-48.
The therapies we are investigating are not approved by the FDA or any other countries’ Health Authorities. This means their safety and efficacy are still being evaluated and have not been established.