MindMed links LSD to reduced anxiety in phase 2b, plots pivotal trials

Mind Medicine has linked its psychedelic medicine to improvements in patients with generalized anxiety disorder. After one hit of lysergide d-tartrate, a hallucinogen better known as LSD, patients in some of the phase 2b dose cohorts experienced reductions in anxiety that persisted through the four-week trial.

Investigators randomized 194 subjects to receive placebo or one of four doses of MM-120, its LSD drug candidate. Subjects took a single dose and were then tracked for four weeks, resulting in data that the biotech believes justify phase 3 development. Unlike in other psychedelic studies, no psychotherapeutic intervention was provided to help patients process the experience.

Scores on the Hamilton Anxiety rating scale (HAM-A) improved in all arms, including the placebo cohorts. After four weeks, subjects on the top two doses of drug candidate experienced significant improvements on HAM-A compared to placebo. The biggest change, a 7.6-point reduction compared to placebo, was seen in the 100 µg cohort. MindMed tested a 200 µg dose but it performed numerically worse than 100 µg on the primary endpoint. 

“Some evidence that there is an underperformance in the 200 µg dose group may represent that level, historically, has been associated with perhaps some more challenging experiences ... that may mitigate some of the positive experience,” Chief Medical Officer Daniel Karlin, M.D., said on a call with investors Thursday. “What we see in the data strongly points us toward the 100 µg dose group as the appropriate go-forward dose,”

MindMed will analyze the data before deciding on its phase 3 dose. 

Other analyses also generated little evidence to suggest there are benefits to increasing the dose beyond 100 µg. MindMed saw significant improvements in psychopathology scores at the top two doses but 100 µg outperformed the higher dose. Similarly, the proportion of patients in remission, as measured by HAM-A, was higher, 50%, at 100 µg than 200 µg, at 35%. 

There are other benefits to the lower dose. MindMed held patients for 12 hours after dosing to ensure perceptual effects had cleared but began checking to see if they were safe to leave earlier. At 100 µg, a wait of eight to 10 hours would have been enough.

Last month, MindMed CEO Robert Barrow told investors the lowest, 25 µg dose was at the “threshold” of activity and the next level up, 50 µg, was “intermediate.” Neither dose had a significant effect on HAM-A.

In terms of safety and tolerability, MindMed saw mostly transient mild-to-moderate adverse events. The most common adverse events at the top two doses were consistent with LSD—illusion, hallucinations and euphoric mood—and 97.5% of those subjects completed the four-week trial. There were no incidents of suicidal or self-injurious behavior.