Accelerated FDA Action for Psychedelics: Insights From Daniel R. Karlin, MD, MA

On April 18, 2026, President Trump issued an Executive Order directing the US Department of Health and Human Services to accelerate access to treatments for patients with serious mental illness—specifically psychedelics.¹

Daniel R. Karlin, MD, MA, the chief medical officer of Definium Therapeutics, while excited by this news, says nothing is changing for his company and their novel candidate, lysergide tartrate (DT120 ODT).

“We’re just absolutely thrilled for the positive regard and attention that this sort of a thing generates,” shared Karlin. “This sort of direction from the President is completely consistent with what we’ve been doing anyway.”

DT120 ODT is now under study for major depressive disorder (MDD) and generalized anxiety disorder (GAD). Just this week, Definium also announced an expansion of the DT120 ODT program with the planned initiation of the phase 3 Haven study in posttraumatic stress disorder (PTSD).² DT120 ODT is Definium’s proprietary and pharmaceutically optimized formulation of LSD. It is an ergoline derivative belonging to the group of classic serotonergic psychedelics, which acts as a partial agonist at serotonin-2A receptors.

“For us, the main focus continues to be that we do good science that demonstrates the conditions for safe and efficacious use of these drugs across the conditions we’re interested in, including MDD and GAD,” said Karlin.

This news will not slow or shift Definium’s scientific enterprise, Karlin told Psychiatric Times, but any efficiencies generated in the review process are welcome.

DT120 ODT Trials

MDD

DT120 ODT for the treatment of MDD is currently being evaluated in the Emerge study, which is fully enrolled with 149 participants randomly assigned 1:1 to receive DT120 ODT 100 µg or placebo. Topline data are anticipated in quarter 2 of 2026. It is also being evaluated in the upcoming Ascend study; sites are activated and first dosing is anticipated to begin soon. Investigators will enroll 175 participants randomly assigned 2:1:2 to DT120 ODT 100 µg, DT120 ODT 50 µg control, or placebo.

GAD

DT120 ODT for the treatment of GAD is currently being evaluated in Voyage study, which is also fully enrolled. The 214 participants are randomly assigned 1:1 to receive DT120 ODT 100 µg or placebo. Topline data are anticipated early in quarter 3 of 2026. Additionally, in the Panorama study, investigators have enrolled over 200 participants and screening is now closed. Participants will be randomly assigned 2:1:2 to receive DT120 ODT 100 µg, DT120 ODT 50 µg control, or placebo, with topline data now anticipated in late quarter 3 of 2026.

PTSD

Lastly, the phase 3 Haven study of DT120 ODT for the treatment of PTSD is expected to enroll approximately 200 participants, who will be randomly assigned 1:1 to receive DT120 ODT or placebo. The study’s primary endpoint is the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) at week 8. The study is expected to initiate in 2027.²

Dr Karlin is the chief medical officer of Definium Therapeutics.

References

1. Accelerating medical treatments for serious mental illness. The White House. April 18, 2026. Accessed April 24, 2026. https://www.whitehouse.gov/presidential-actions/2026/04/accelerating-medical-treatments-for-serious-mental-illness/

2. Definium Therapeutics highlights DT120 ODT (lysergide tartrate) clinical advancements and commercial strategy at Investor and Analyst Day. News release. April 22, 2026. Accessed April 24, 2026. https://ir.definiumtx.com/news-events/press-releases/detail/223/definium-therapeutics-highlights-dt120-odt-lysergide-tartrate-clinical-advancements-and-commercial-strategy-at-investor-and-analyst-day