Acadia Pharmaceuticals Announces Phase 3 Enabling Topline Results from Phase 2 RADIANT Study of Remlifanserin for the Treatment of Alzheimer’s Disease Psychosis (ADP)

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SAN DIEGO — Acadia Pharmaceuticals Inc. (Nasdaq: ACAD) today announced Phase 3 enabling topline results from the Phase 2 portion of the ongoing RADIANT clinical trial program evaluating remlifanserin for the treatment of hallucinations and delusions associated with Alzheimer’s disease psychosis (ADP).

For the primary endpoint of change from baseline in the Scale for the Assessment of Positive Symptoms-Hallucinations and Delusions subscales (SAPS-H+D), once daily 60 mg remlifanserin demonstrated a change of -12.6 versus a -10.4 change for placebo at week 6, yielding a standardized effect size of 0.26 (p=0.0603). For the key secondary endpoint, Clinical Global Impression – Severity (CGI-S-ADP), the 60 mg dose achieved a change from baseline of -1.3 versus a change of -0.9 for placebo at week 6, yielding a standardized effect size of 0.37 [p=0.0077 (nominal)]. On both efficacy measures, the difference in the 60 mg dose versus placebo increased through the 6-week treatment period. The 30 mg dose showed minimal improvement across endpoints compared to placebo. All analyses were performed in the pre-specified modified full analysis set (mFAS 1 ) population.

In this study, across both doses, remlifanserin demonstrated a favorable safety profile, with rates of adverse events, serious adverse events, and discontinuations due to adverse events, similar to placebo. There was no signal of QT prolongation versus placebo. This dataset suggests no negative impact on motor symptoms or cognition. Additionally, there were no deaths in the remlifanserin treatment arms.

Given these data, Acadia plans to continue enrolling its two ongoing Phase 3 studies evaluating remlifanserin in ADP while implementing amendments to the Phase 3 program, including removing the 30 mg dosage arm.

“We are pleased that the Phase 2 RADIANT data support continuation of the Phase 3 ADP program, with new insights helping us to refine the program for future regulatory success. These results provide valuable information regarding the efficacy, safety and tolerability of once daily remlifanserin in Alzheimer’s disease psychosis,” said Catherine Owen Adams, Chief Executive Officer of Acadia Pharmaceuticals. “We are excited about the potential of remlifanserin in this area of high unmet need, for which there are no currently approved therapies.”

“The Phase 2 RADIANT findings provide encouraging evidence that 60 mg once daily remlifanserin may have the potential to reduce hallucinations and delusions in patients with Alzheimer’s disease,” said Jeffrey Cummings, M.D., Sc.D., Director of the Chambers-Grundy Center for Transformative Neuroscience, University of Nevada, Las Vegas. “This patient population has a significant need for an efficacious medication that is well tolerated, convenient to administer, and is compatible with the many concomitant medications commonly used by patients with Alzheimer’s disease.