atai Life Sciences (NASDAQ:ATAI) ("atai"), a clinical-stage biopharmaceutical company on a mission to develop highly effective mental health treatments to transform patient outcomes, and Beckley Psytech Limited ("Beckley Psytech"), a private clinical-stage biopharmaceutical company pioneering the next generation of mental health treatments, today jointly announced positive topline results from the eight-week, quadruple-masked, dose-finding, core stage of the Phase 2b clinical trial evaluating the efficacy and safety of a single dose of BPL-003 (intranasal mebufotenin (5-MeO-DMT) benzoate) in patients with treatment-resistant depression (TRD). The study achieved its primary endpoint as well as all key secondary endpoints. At Day 29, a single 12 mg dose of BPL-003 demonstrated a statistically significant reduction in depressive symptoms, as measured by the Montgomery-Åsberg Depression Rating Scale (MADRS), with a mean decrease of 11.1 points from baseline compared to a 5.8 point reduction in the 0.3 mg comparator group (p = 0.0038). For the key secondary efficacy endpoints, a single 8 mg dose of BPL-003 also showed significant improvement at Day 29, with a mean MADRS score reduction of 12.1 points (p=0.0025 for change vs. 0.3 mg control). Notably, both the 8mg and 12mg doses of BPL-003 showed statistically significant improvements in MADRS scores as early as one day after dosing, with effects generally maintained out to Week 8.
Safety and efficacy results from this study support the selection of the 8 mg dose of BPL-003 for advancement into Phase 3 clinical studies. atai and Beckley Psytech plan to engage with the U.S. Food and Drug Administration (FDA) and other applicable agencies regarding the Phase 3 trial design for patients with treatment-resistant depression in the coming months.
With these positive Phase 2b results, the pre-agreed success criteria for the proposed strategic combination between atai and Beckley Psytech, which was announced in June 2025, has been achieved and the strategic combination is now expected to progress to atai shareholder approval stage. The atai Beckley combination is expected to create a global leader in short time in-clinic psychedelic-based mental health therapies.
Cosmo Feilding Mellen, Chief Executive Officer and Co-Founder of Beckley Psytech, said: "The achievement of our primary and secondary endpoints in this study represents an important milestone in the development of BPL-003 and reinforces its potential to be a viable treatment option for patients and healthcare systems. We are particularly encouraged that a single 8 mg or 12 mg dose of BPL-003 showed rapid and durable efficacy results, favourable tolerability and a short time in-clinic, giving us important flexibility in optimising the design of future trials. Thank you to all of the patients and study partners who participated in this study - we now look forward to preparing for end-of-Phase 2 meetings with regulators and moving forward with our strategic combination with atai Life Sciences to form atai Beckley, a global leader in psychedelic-based mental health treatments."
The Phase 2b clinical study was conducted at 38 sites across six countries and enrolled a total of 193 patients with moderate-to-severe TRD (defined as non-response to two or more prior treatments in the current depressive episode) (NCT05870540). It is the largest controlled clinical study to investigate mebufotenin and the only blinded Phase 2b study of mebufotenin to include the United States. Patients were randomized to receive a single 12 mg (n=73), 8 mg (n=46), or 0.3 mg comparator (n=74) dose of BPL-003 and were followed for eight weeks with efficacy assessments conducted by centralised, blinded raters using the MADRS at Day 2, Day 8, Day 29 and Day 57.
Key efficacy findings:
Key safety findings:
Additional data from the core study is expected to be shared through publications and medical meetings in the future.