That could cost you big, Acadia Pharmaceuticals stock tumbles on mixed trial results

Acadia Pharmaceuticals Inc. (NASDAQ: ACAD) shares fell 6% after the company announced Phase 2 results from its RADIANT study of remlifanserin for the treatment of Alzheimer’s disease psychosis that narrowly missed the primary endpoint.

The study missed its primary endpoint of SAPS H+D with a p-value of 0.0603, though it achieved nominal significance on the key secondary endpoint of CGI-S-ADP with a p-value of 0.0077. The 60 mg once daily dose of remlifanserin demonstrated a change of -12.6 versus -10.4 for placebo at week 6 on the primary endpoint, yielding a standardized effect size of 0.26.

For the key secondary endpoint measuring Clinical Global Impression-Severity, the 60 mg dose achieved a change from baseline of -1.3 versus -0.9 for placebo at week 6, with a standardized effect size of 0.37. The 30 mg dose showed minimal improvement across endpoints compared to placebo.

Despite missing the primary endpoint, Acadia plans to continue enrolling its two ongoing Phase 3 studies evaluating remlifanserin in Alzheimer’s disease psychosis while removing the 30 mg dosage arm from the program.