The goal of this clinical trial is to learn if MDMA-assisted therapy is safe and effective in people with at least severe PTSD.

The main question it aims to answer is: Do three sessions of MDMA-assisted therapy reduce PTSD symptoms?

Researchers will compare three sessions of MDMA-assisted therapy with an initial dose of 80 to 120 mg to three sessions of placebo with therapy.

Participants will undergo three preparatory sessions without any study drug, followed by three MDMA-assisted therapy or placebo with therapy sessions. Each medication session will be followed by three integrative therapy sessions without study drug.

This multi-site, double-blind, placebo-controlled, randomized Phase 3 study will assess the efficacy and safety of MDMA-assisted therapy versus placebo with therapy in participants diagnosed with at least severe PTSD. The study will be conducted in N ≈ 100 participants. Participants will be randomized to one of two groups at a 1:1 ratio. An initial dose of midomafetamine HCl or placebo, followed by a supplemental half-dose unless contraindicated, is administered during the Treatment Period with manualized therapy in three monthly Experimental Sessions. This ~12-week Treatment Period is preceded by three Preparatory Sessions. During the Treatment Period, each Experimental Session is followed by three Integrative Sessions of non-drug psychotherapy. Initial doses per Experimental Session include 80 mg or 120 mg of midomafetamine HCl or placebo followed 1.5 to 2 hours later by a supplemental half-dose (40 or 60 mg). Total amounts of midomafetamine HCl to be administered per Experimental Session range from 80 mg to 180 mg.

The primary endpoint is change from baseline in Clinician Administered PTSD Scale for DSM-V (CAPS-5) to 18 weeks post-Baseline. Drug safety will be assessed by measuring blood pressure, heart rate and body temperature during Experimental Sessions, collecting adverse events and measuring suicidal thoughts or behaviors with the Columbia Suicide Severity Rating Scale (adapted C-SSRS).

Inclusion Criteria:

• Are at least 18 years old
• Are fluent in speaking and reading the predominantly used or recognized language of the study site
• Are able to swallow pills
• Agree to have study visits recorded, including Experimental Sessions, Independent Rater assessments, and non-drug psychotherapy sessions
• Must provide a contact (relative, spouse, close friend or other caregiver) who is willing and able to be reached by the investigators in the event of a participant becoming suicidal or unreachable.
• Must agree to inform the investigators within 48 hours of any medical conditions and procedures
• If of childbearing potential, must have a negative pregnancy test at study entry and prior to each Experimental Session, and must agree to use adequate birth control through 10 days after the last Experimental Session.
• Must not participate in any other interventional clinical trials during the duration of the study
• Must be willing to remain overnight at the study site after each Experimental Session and be driven home after, and commit to medication dosing, therapy, and study procedures
• At baseline, meet DSM-5 criteria for current severe PTSD

Exclusion Criteria:

• Are not able to give adequate informed consent
• Have uncontrolled hypertension
• Have a marked baseline prolongation of QT/QTc interval (e.g., repeated demonstration of a QTc interval >450 milliseconds [ms] in males and >460 ms in females corrected by Bazett's formula)
• Have a history of additional risk factors for Torsade de pointes (e.g., heart failure, hypokalemia, family history of Long QT Syndrome)
• Have evidence or history of significant medical disorders, such as myocardial infarction, cerebrovascular accident, or aneurysm
• Have symptomatic liver disease
• Have history of hyponatremia or hyperthermia
• Weigh less than 48 kilograms (kg)
• Are pregnant or nursing, or are of childbearing potential and are not practicing an effective means of birth control
• Have an active illicit or prescription drug use disorder
• Have used Ecstasy (material represented as containing MDMA) more than 10 times within the last 10 years or at least once within 6 months of the first Experimental Session; or have previously participated in a MAPS-sponsored MDMA clinical trial.

We will share outcome data appearing in any published reports upon request.

Data and study-related documents will be available when the database has been locked and data has been unblinded.

Interested persons should correspond with the central contact for the multisite study.

Use of separate databases for outcome measures and safety data. Assessment made by pool of independent raters. Randomization will be managed via an Interactive Web Randomization System (IWRS) based on a centralized randomization schedule developed by an independent third-party vendor to maintain blinding.