Definium's LSD-based drug lowers anxiety in second successful late-stage study

Definium Therapeutics announced on Monday that its LSD-based treatment, DT120, effectively reduced symptoms of generalized anxiety disorder (GAD) in a recent trial, marking their second successful late-stage study for the condition. The single 100-microgram dose of DT120, which is the chemical name for the psychedelic drug LSD, resulted in a 9.8-point decrease in anxiety scores after 12 weeks, compared to a 4.7-point decline for placebo.

The company reported that these benefits appeared as early as the second day and were sustained through week 12.

Regulatory and investor enthusiasm for psychedelic-based therapies have driven Definium shares nearly triple in value this year. The company's CEO, Robert Barrow, stated that having two studies confirming the drug's efficacy will increase their chances of receiving approval, as around a dozen programs have attempted to secure approval for GAD and have failed. GAD affects approximately 26 million US adults and is typically treated with antidepressants, anti-anxiety medicines, and psychotherapy.

The new trial included 245 patients who received either the 100-microgram dose of DT120 or a lower 50-microgram dose, as well as a placebo. The lower-dose arm was added to address functional unblinding, a limitation in clinical trials where patients can guess treatment assignments due to distinct side effects or unmistakable drug experiences.

Despite this, at both doses, patients were able to accurately identify when they received the drug rather than the placebo, according to Barrow. The higher efficacy of the 100-microgram dose compared to the 50-microgram dose provides a more favorable discussion with regulators, he added.

Definium plans to file a marketing application with the US Food and Drug Administration (FDA) in the first half of 2027.