Single Treatment With MM120 (Lysergide) in Generalized Anxiety Disorder: A Randomized Clinical Trial

This Phase IIb randomised, double-blind, placebo-controlled trial (n=198) found that single doses of 100 µg and 200 µg of MM120 (lysergide D-tartrate) significantly reduced anxiety symptoms at 4 weeks in adults with moderate to severe generalised anxiety disorder (GAD), with dose-dependent effects and adverse events including visual perceptual changes, nausea, and headache.

Abstract of Single Treatment With MM120 (Lysergide) in Generalized Anxiety Disorder

Importance: Effective and well-tolerated pharmacotherapies for generalized anxiety disorder (GAD), which is one of the most common psychiatric disorders, are needed.

Objective: To determine the dose-response relationship of MM120 (lysergide D-tartrate) in adults with moderate to severe GAD.

Design, Settings, and Participants: This phase 2b, multicenter, randomized, double-blind, placebo-controlled study enrolled 198 adults aged 18 to 74 years with a primary GAD diagnosis who presented with moderate to severe symptoms (defined by a Hamilton Anxiety Rating Scale [HAM-A] score ≥20) and was conducted at 22 outpatient psychiatric research sites in the US from August 2022 to August 2023. The anxiety and depression end point assessments were conducted by independent central raters who were blinded to the trial protocol, treatment allocation, and study visit date. The last date of follow-up was November 27, 2023.

Interventions: Participants were randomized to receive a single (freebase equivalent) treatment dose with 25 µg (n = 39), 50 µg (n = 40), 100 µg (n = 40), or 200 µg (n = 40) of MM120 or placebo (n = 39).

Main Outcome and Measures: The primary outcome was a dose-response relationship assessed using the multiple comparison procedure modeling (MCP-Mod) method for change in HAM-A score at 4 weeks (score range, 0-56; higher scores indicate greater severity; ≤7 indicates no or minimal anxiety; 8-14, mild; 15-23, moderate; and ≥24, severe). The minimal clinically important difference was 2.5 points.

Results: Of the 198 participants randomized, 194 were included in the full analysis set (mean age, 41.3 [SD, 13.6] years; 56.7% were female; and 3.6% were Asian, 7.7% were Black or African American, and 83.0% were White). The dose-response relationship assessed using the MCP-Mod method for change in HAM-A score at week 4 was statistically significant for the 100-µg and the 200-µg dose groups vs placebo (least-squares mean difference, −5.0 points [95% CI, −9.6 to −0.4 points] with 100 µg of MM120 and −6.0 points [95% CI, −9.8 to −2.0 points] with 200 µg of MM120) but the 25-µg and 50-µg dose groups did not reach significance vs placebo (least-squares mean difference, −1.2 points [95% CI, −6.0 to 3.5 points] with 25 µg of MM120 and −1.8 points [95% CI, −7.6 to 4.0 points] with 50 µg of MM120). The adverse events were consistent with the expected effects of MM120. The most common adverse events were visual perceptual changes (illusion, pseudo-hallucination, and visual hallucination), which occurred in 46.2% of participants who received 25 µg of MM120, in 75.0% who received 50 µg, in 92.5% who received 100 µg, in 100% who received 200 µg, and in 10.3% who received placebo; nausea occurred in 7.7%, 27.5%, 40.0%, 60.0%, and 7.7%, respectively; and headache occurred in 12.8%, 22.5%, 35.0%, 27.5%, and 23.1%.

Conclusions and Relevance: In participants with moderate to severe GAD, a single dose of MM120 produced a dose-dependent reduction in anxiety. These results support the dose-dependent efficacy of MM120 and inform the dose selection for phase 3 pivotal trials.

Authors: Reid Robison, Robert Barrow, Craig Conant, Eric Foster, Jamie M. Freedman, Paula L. Jacobsen, Jamileh Jemison, Sarah M. Karas, Daniel R. Karlin, Todd M. Solomon, Miri Halperin Wernli & Maurizio Fava

Summary of Single Treatment With MM120 (Lysergide) in Generalized Anxiety Disorder

The authors begin by discussing generalised anxiety disorder (GAD), which is characterised by excessive and persistent worry that is difficult to control and often accompanied by physical symptoms such as restlessness, muscle tension, and difficulty sleeping. GAD is both common and disabling, leading to significant impairment in daily functioning and quality of life. Standard treatments include antidepressants, benzodiazepines, and psychotherapy. However, many patients either fail to respond adequately or discontinue due to side effects, highlighting the urgent need for alternative therapeutic approaches.

The authors note growing interest in psychedelic-assisted treatments, with early research showing potential benefits in various psychiatric disorders. In this study, they focus on MM120, an experimental formulation of lysergide D-tartrate (a form of LSD), hypothesising that a single dose may alleviate symptoms of GAD. Previous smaller studies suggested that psychedelics could reduce anxiety and depression through effects on serotonin receptors and by promoting neuroplasticity, which refers to the brain’s ability to reorganise itself and form new neural connections.

The purpose of this Phase IIb study was to rigorously test the efficacy, safety, and dose-response relationship of MM120 in adults with moderate to severe GAD. The researchers aimed to determine whether MM120 could provide sustained relief from anxiety symptoms following a single administration, and to identify the optimal therapeutic dose for future trials.

Methods

Study design

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Find this paper

Single Treatment With MM120 (Lysergide) in Generalized Anxiety Disorder: A Randomized Clinical Trial

https://doi.org/10.1001/jama.2025.13481

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Cite this paper (APA)

Robison, R., Barrow, R., Conant, C., Foster, E., Freedman, J. M., Jacobsen, P. L., ... & Fava, M. (2025). Single treatment with MM120 (lysergide) in generalized anxiety disorder: a randomized clinical trial. JAMA.

Study details

Compounds studied
LSD

Topics studied
Anxiety

Study characteristics
Original Placebo-Controlled Active Placebo Double-Blind Randomized

Participants
198 Humans

Institutes

Institutes associated with this publication

MindMed
MindMed is one of the largest companies in the psychedelics space and is developing various psychedelics for mental health disorders.

Compound Details

The psychedelics given at which dose and how many times

LSD 100 - 200
μg | 1x

Linked Clinical Trial

A Dose-Finding Study of MM-120 for the Treatment of Anxiety Symptoms
This is a Phase II, multi-centre, randomized, double-blind, parallel-group, dose-finding study to assess the effect of four doses of MM-120 (25, 50, 100 or 200 μg LSD freebase-equivalent) for the treatment of anxiety symptoms in subjects diagnosed with generalized anxiety disorder (GAD).