AtaiBeckley NV (NASDAQ:ATAI, XETRA:9VC) reported positive topline results from an exploratory Phase 2a trial evaluating its oral R-MDMA candidate, EMP-01, in adults with social anxiety disorder (SAD), with the study meeting its primary safety objective and showing encouraging efficacy signals.
The clinical-stage biotechnology company said the randomized, double-blind, placebo-controlled study enrolled 71 adults with moderate-to-severe SAD across seven sites in the United Kingdom. Participants received two in-clinic administrations of EMP-01 (225 mg) or placebo spaced 28 days apart, without adjunctive psychotherapy.
The trial’s primary endpoint of safety and tolerability through Day 43 was achieved. The company reported no serious adverse events and no treatment-emergent suicidal behaviour or intent. Most adverse events were mild or moderate and resolved without intervention.
On secondary measures, EMP-01 demonstrated greater symptom reduction than placebo on the Liebowitz Social Anxiety Scale (LSAS). At Day 43, the treatment group showed a least squares mean reduction of 28.53 points from baseline compared with 16.67 points for placebo. The placebo-adjusted reduction of 11.85 points corresponded to a moderate effect size.
AtaiBeckley noted the study was not powered for statistical significance but said the magnitude of improvement was consistent with clinically meaningful benefit. The company also highlighted that symptom reductions observed after two doses over six weeks were comparable in cross-trial comparisons to outcomes typically reported after 8 to 12 weeks of daily SSRI or SNRI therapy.
On the Clinician Global Impression–Improvement (CGI-I) scale, 49% of patients receiving EMP-01 were rated as “very much improved” or “much improved,” compared with 15% in the placebo arm, according to AtaiBeckley. The 34-percentage-point difference equated to a number needed to treat of 2.95.
Subscale analysis of the LSAS showed improvements in both fear and avoidance domains. By Day 43, fear scores improved by 13.7 points (25.4%) in the EMP-01 group versus 8.1 points (15.5%) for placebo, while avoidance improved by 15.1 points (28.6%) versus 8.5 points (17.1%), respectively.
The company said the early, parallel improvements across both emotional and behavioral measures, observed after two dosing sessions without psychotherapy, suggest EMP-01 may affect multiple dimensions of social anxiety disorder.
“We are encouraged by both the strength of the signal and our ability to deliver the topline results from this exploratory Phase 2a study on time and with a robust dataset,” AtaiBeckley CEO Srinivas Rao said in a statement.
“The consistent pattern of improvement observed across secondary and exploratory efficacy endpoints, together with a generally favorable safety and tolerability profile, provides meaningful validation of both the compound and our clinical development model as we assess the next phase of advancement.”
Professor Murray Stein, Distinguished Professor of Psychiatry and Public Health at the University of California San Diego (UCSD), and consultant to AtaiBeckley, described the initial findings from the trial as “remarkable.”
“Social Anxiety Disorder is a serious, often chronic and disabling condition affecting millions of Americans, and there have been no therapeutic advances in its pharmacological treatment in over 20 years,” Professor Stein said. “While preliminary, this study suggests that EMP-01 has the potential to make a tremendous impact on the lives of patients and their families. I hope future trials will be conducted to confirm these very exciting findings.”
AtaiBeckley said more detailed analyses will be presented at upcoming scientific meetings and will inform its future development plans.