Phase 2 Pilot Safety Study of MDMA-assisted Therapy for Social Anxiety in Autistic Adults

The main objective of this study was to collect safety data to examine whether MDMA-assisted therapy was tolerated and to estimate symptom reduction in social anxiety and other psychiatric symptoms that are common in the adult autistic population as evaluated by standard clinical measures. The primary outcome measure was change in social anxiety symptoms as measured by the Liebowitz Social Anxiety Scale (LSAS) \[Heimberg et al., 1999\]. Each of the 12 subjects participated in two blinded experimental sessions, with either MDMA or placebo, which lasted seven hours. Before experimental sessions, participants underwent three separate hour-long preparatory sessions to learn what to expect and complete pre-treatment assignments. After each experimental session, participants underwent three separate hour-long integrative sessions to help integrate their experiences and insights from the experimental sessions. This study was designed as a dose escalation study to assist with the exploration of safety and finding the most effective dose in this population. Upon enrollment, participants (Group 1) were randomized to receive one dose of either placebo or 75 mg of midomafetamine HCl. In the second experimental session one month later, Group 1 subjects randomized to MDMA escalated to 100 mg of midomafetamine HCl, unless contraindicated. The second group of subjects enrolled (Group 2) were randomized to receive one dose of either placebo or 100 mg of midomafetamine HCl. In the second experimental session one month later, Group 2 subjects randomized to MDMA escalated to 125 mg of midomafetamine HCl, unless contraindicated. The blind was maintained through the six-month follow-up. In Stage 2 after the blind was broken, subjects who received placebo in Stage 1 were offered an open-label extension with two experimental sessions of MDMA-assisted therapy scheduled one month apart. Subjects received 75 mg of midomafetamine HCl in the first session and escalated to 125 mg of midomafetamine HCl in the second session, unless contraindicated.