Definium rises on second successful late-stage study of LSD-based anxiety drug

Shares of biotech firm Definium Therapeutics DFTX.O rise 19.4% to $46.09 premarket.

The company said its experimental LSD-based anxiety disorder drug, DT120, met the main goal and all key secondary goals in a late-stage study in generalized anxiety disorder, a condition marked by persistent and excessive worry.

It said a single 100-microgram dose delivered a 5.1-point placebo-adjusted improvement on the Hamilton Anxiety Rating Scale at 12 weeks.

Patients showed improvement as early as Day 2, with benefits sustained through Week 12.

The company said 32% of treated patients achieved at least a 50% reduction in anxiety symptoms versus 14% on placebo.

Definium plans to meet U.S. regulators later this year and seek approval in the first half of 2027.

As of the last close, the stock was up about 190% year to date.