Client Alerts  - Psychedelics and Mental Health Therapeutics Mar 21, 2024

FDA Breakthrough Therapy Designation for LSD Formulation

MindMed Announces FDA Breakthrough Therapy Designation and Positive Findings from Phase 2B Study of LSD Formulation for Generalized Anxiety Disorder

On March 7, 2024, the biopharmaceutical company Mind Medicine (MindMed) Inc. announced that the U.S. Food and Drug Administration (FDA) has granted breakthrough therapy designation to one of the company’s products in development, MM120 (lysergide d-tartrate) — an innovative LSD formulation, targeting the treatment of Generalized Anxiety Disorder (GAD).1 This designation not only spotlights LSD’s potential in medicinal psychedelics but also marks a significant leap towards addressing the pressing need for effective GAD therapies.

Breakthrough therapy designation by the FDA is intended to speed up the development and review of medications for serious conditions where preliminary clinical evidence has suggested the medication may show a substantial advantage over existing treatments on a clinically significant endpoint(s).2

This marks a significant development for the medicinal psychedelics sector — adding an LSD formulation to the list of compounds (MDMA and psilocybin) within the psychedelic space to have received this type of breakthrough therapy designation from the FDA. In 2017, the FDA granted breakthrough therapy designation to Lykos Therapeutics (formerly MAPS PBC) for their formulation of MDMA, a psychoactive compound often grouped in the category of psychedelics, in combination with psychotherapy, for the treatment of post-traumatic stress disorder (PTSD).3 In addition, breakthrough therapy designation was granted by the FDA to Compass Pathways in 2018 for psilocybin therapy for treatment-resistant depression4 and to Usona Institute in 2019 for psilocybin for major depressive disorder (MDD).5 Just recently, on March 13, 2024, Cybin announced that the FDA granted breakthrough therapy designation to the company’s deuterated psilocybin analog, CYB003, for the adjunctive treatment (i.e., in patients taking one or more antidepressant medications) of MDD.6

According to MindMed’s press release, the FDA breakthrough therapy designation was granted based on initial clinical data from their Phase 2b study — a dose-finding study to evaluate the effect of four doses of MM120 (25, 50, 100 or 200 micrograms (μg)) on GAD, other research conducted by MindMed and an unmet need for GAD therapies, especially in patients who have not responded to existing medications. In the press release, MindMed’s CEO Robert Barrow stated: “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.”7

Notably, unlike Lykos Therapeutics’ product of MDMA with accompanying psychotherapy, the LSD formulation in MindMed’s Phase 2b study was administered in a supervised setting, but without any accompanying psychotherapy.

MindMed’s Phase 2b Study

MindMed’s Phase 2b study (known as MMED008) is a dose-optimization, double-blind, randomized placebo-controlled trial of 198 patients with severe GAD symptoms. Patients were randomized to receive a single dose of MM120 25, 50, 100, 200 μg or placebo in a monitored clinical setting with no additional psychotherapy. Prior to treatment, patients were tapered off antianxiety or antidepressant treatments.

The company previously announced achievement of the study’s primary endpoint — a statistically significant reduction compared to placebo on Hamilton Anxiety rating scale (HAM-A) scores at week four. In their March 7, 2024 press release, the company announced meeting the study’s key secondary endpoint with MM120 100 μg, the dose determined to have optimal clinical activity. MindMed reported a statistically significant reduction with MM120 100 μg compared to placebo in HAM-A scores at week 12, with a 65% clinical response rate and 48% clinical remission rate sustained to week 12. The company also reported statistically significant improvement in Clinical Global Impressions – Severity (CGI-S) scores in the 100 μg group at week 12. These findings underscore MM120’s potential as a standalone treatment, offering a simplified administration method without the need for accompanying psychotherapy.

According to the press release, treatment with MM120 was “generally well-tolerated with most adverse events rated as mild to moderate, transient and occurring on dosing day, and being consistent with expected acute effects of the study drug.”8 Some of the adverse events included hallucinations, euphoric mood, anxiety, abnormal thinking or feeling, headache, pins and needles sensation, dizziness, tremor, nausea, vomiting and excessive sweating.

Findings from this study will be presented at the American Psychiatric Association’s annual meeting on May 4-8, 2024, and are also being submitted for publication in a medical journal. According to the press release, MindMed intends to have an End-of-Phase 2 meeting with the FDA in the first half of 2024 and begin its Phase 3 clinical program in the second half of 2024.


Yet another breakthrough therapy designation by the FDA for a medicinal psychedelic product in development is a possible sign that the FDA is increasingly recognizing the potential of psychedelic therapies to meet the unmet needs of patients for effective treatments of mental health conditions such as PTSD, depression and anxiety.

A notable distinction of MindMed’s Phase 2b trial is that potentially favorable results were reported with supervised administration of MM120 alone without additional psychotherapy. The effects of Lykos Therapeutics’ MDMA product were studied alongside accompanying psychotherapy, and those of Compass Pathways’ and Usona Institute’s psilocybin products were studied along with psychological support.9, 10, 11 The associated additional costs to psychedelic medications requiring accompanying psychotherapy, such as therapist training and compensation as well as additional infrastructure needs, will likely differ greatly from medications which only require supervised administration. This has implications for drug developers as well as clinicians, health care organizations and insurers who are trying to plan for the rollout of psychedelic therapies if — and likely when — they ultimately gain FDA approval.

An accompanying conference call/webcast by MindMed on March 7, 2024,12 included a discussion on the commercial model of MM120, which was compared to that of Spravato (esketamine) nasal spray — an FDA-approved dissociative medication used for treatment of depression and administered under the supervision of a healthcare provider.13 MindMed discussed that more than 3,500 certified clinics exist for the delivery of Spravato and could represent initial targets for MM120 if the product gains FDA approval. According to MindMed, the certified clinics for Spravato delivery could seamlessly transition to delivery of MM120 upon FDA approval by engaging with the current infrastructure and using similar space, equipment, reimbursement, documentation and logistic pathways.

MindMed’s achievement signifies a potential shift in mental health treatment paradigms, suggesting a future with additional effective and manageable treatments for anxiety disorders, pending additional testing and FDA approval. Unlike therapies requiring comprehensive psychotherapy, MM120 promises a more streamlined approach to treatment, potentially reducing costs and logistical hurdles. Staying informed on how psychedelic medications are moving through the FDA-approval process is key for drug developers trying to optimize their chances of FDA approval and for clinicians, health care organizations and insurers planning for psychedelic medication rollouts.

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1   Press Release, MindMed, MindMed Receives FDA Breakthrough Therapy Designation and Announces Positive 12-Week Durability Data From Phase 2B Study of MM120 for Generalized Anxiety Disorder (Mar. 07, 2024, 6:00 AM),

2   U.S. Food & Drug Admin., Breakthrough Therapy (Jan. 4, 2018),

3   Press Release, Lykos Therapeutics, MAPS PBC Announces Submission of New Drug Application to the FDA for MDMA-Assisted Therapy for PTSD (Dec. 12, 2023),

4   Press Release, Compass Pathways, Compass Pathways receives FDA Breakthrough Therapy designation for psilocybin therapy for treatment-resistant depression (Oct. 23, 2018),

5   Press Release, Usona Institute, FDA grants Breakthrough Therapy Designation to Usona Institute’s psilocybin program for major depressive disorder (Nov. 22, 2019),

6   Press Release, Cybin, Cybin Receives FDA Breakthrough Therapy Designation for its Novel Psychedelic Molecule CYB003 and Announces Positive Four-Month Durability Data in Major Depressive Disorder (Mar 13, 2024),

7   MindMed, supra note 1.

8   Id.

9   Mitchell, J.M., Ot’alora G., M., van der Kolk, B. et al., MDMA-assisted therapy for moderate to severe PTSD: a randomized, placebo-controlled phase 3 trial, Nat Med 2023 Oct;29(10):2473-2480.

10   Goodwin GM, Aaronson ST, Alvarez O, et al., Single-Dose Psilocybin for a Treatment-Resistant Episode of Major Depression, N Engl J Med 2022 Nov 3;387(18):1637-1648.

11   Raison CL, Sanacora G, Woolley J, et al., Single-Dose Psilocybin Treatment for Major Depressive Disorder: A Randomized Clinical Trial, JAMA 2023 Sep 5;330(9):843-853. Erratum in: JAMA 2024 Feb. 27;331(8):710.

12   MindMed Conference Call and Webcast (Mar. 7, 2024),

13   Spravato Prescribing Information (Oct. 2023),

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