The US Food and Drug Administration (FDA) has granted breakthrough designation to an LSD-based treatment for generalized anxiety disorder (GAD) based on promising topline data from a phase 2b clinical trial. Mind Medicine (MindMed) Inc is developing the treatment — MM120 (lysergide d-tartrate).
In a news release the company reports that a single oral dose of MM120 met its key secondary endpoint, maintaining "clinically and statistically significant" reductions in Hamilton Anxiety Scale (HAM-A) score, compared with placebo, at 12 weeks with a 65% clinical response rate and 48% clinical remission rate.
The company previously announced statistically significant improvements on the HAM-A compared with placebo at 4 weeks, which was the trial's primary endpoint.
"I've conducted clinical research studies in psychiatry for over two decades and have seen studies of many drugs under development for the treatment of anxiety. That MM120 exhibited rapid and robust efficacy, solidly sustained for 12 weeks after a single dose, is truly remarkable," study investigator David Feifel, MD, PhD, professor emeritus of psychiatry at the University of California, San Diego, and director of the Kadima Neuropsychiatry Institute in La Jolla, California, said in the news release.
"These results suggest the potential MM120 has in the treatment of anxiety, and those of us who struggle every day to alleviate anxiety in our patients look forward to seeing results from future phase 3 trials," Feifel added.
MM120 was administered as a single dose in a monitored clinical setting with no additional therapeutic intervention. Prior to treatment with MM120, study participants were clinically tapered and then washed out from any anxiolytic or antidepressant treatments and did not receive any form of study-related psychotherapy for the duration of their participation in the study.
MM120 100 µg — the dose that demonstrated optimal clinical activity — produced a 7.7-point improvement over placebo at week 12 (P < .003; Cohen's d = 0.81), with a 65% clinical response rate and a 48% clinical remission rate sustained to week 12.
Also at week 12, Clinical Global Impressions-Severity (CGI-S) scores on average improved from 4.8 to 2.2 in the 100-µg dose group, representing a two-category shift from 'markedly ill' to 'borderline ill' at week 12 (P < .004), the company reported.
Improvement was noted as early as study day 2, and durable with further improvements observed in mean HAM-A or CGI-S scores between 4 and 12 weeks.
MM120 was generally well-tolerated with most adverse events rated as mild to moderate and transient and occurred on the day of administration day, in line with the expected acute effects of the study drug.
The most common adverse events on dosing day included illusion, hallucinations, euphoric mood, anxiety, abnormal thinking, headache, paresthesia, dizziness, tremor, nausea, vomiting, feeling abnormal, mydriasis, and hyperhidrosis.
The company plans to hold an end-of-phase 2 meeting with the FDA in the first half of 2024 and start phase 3 testing in the second half of 2024.
"The FDA's decision to designate MM120 as a breakthrough therapy for GAD and the durability data from our phase 2b study provide further validation of the important potential role this treatment can play in addressing the huge unmet need among individuals living with GAD," Robert Barrow, director and CEO of MindMed said in the release.
The primary data analyses from the trial will be presented at the American Psychiatric Association (APA) annual meeting in May.
