The study enrolled 223 adults suffering from moderate to severe depression who have found limited success with standard antidepressant regimens. By testing HLP003—a deuterated psilocin analogue—against a placebo in a two-dose cycle, researchers aim to establish a more effective alternative to existing adjunctive therapies, which are often hampered by side effects like sedation and weight gain.

Interim CEO Eric So credited the early completion to rigorous site selection and efficient screening, noting that the trial population matches the severity levels seen in the company's earlier Phase 2 data. That previous study reported significant efficacy, with participants showing a 23-point reduction on the Montgomery-Asberg Depression Rating Scale 12 months after treatment. With the APPROACH cohort now finalized, the company is turning its attention to its secondary trial, EMBRACE, and the EXTEND long-term safety study, while preparing for a potential FDA submission in 2028.