A Closer Look at Definium's Phase 3 LSD for Generalised Anxiety Disorder Readout and DT120's Efficacy

Definium Therapeutics' Phase 3 study of a single dose of LSD candidate DT120 for generalised anxiety disorder met its primary and key secondary endpoints, but researchers question whether the observed efficacy is competitive with established treatments. Neuroscientist Martijn Arns highlighted 14% remission and 43% response rates, compared with approximately 28-45% remission reported for some FDA-approved GAD medicines. He suggested that psychedelic trials may be under-dosing patients by using too few treatment sessions, while noting that response and remission appeared to increase with further re-treatment in interim Part B data. The article cautions that follow-up findings may be affected by selection bias and were not necessarily powered for definitive conclusions, but says similar trends across studies challenge the assumption that one psychedelic treatment should be sufficient. It also benchmarks single-dose results against chronically dosed GAD medicines using HAM-A changes and includes discussion with Definium CMO Dan Karlin.