-- Meaningful and consistent efficacy trends across endpoints support continuing with Phase 3 development of 60 mg once daily remlifanserin in ADP, with demonstrated evidence of dose effect

-- Narrowly missed primary endpoint of SAPS H+D (p=0.0603) with significance (nominal) on key secondary endpoint of CGI-S-ADP (p=0.0077)

-- Favorable safety and tolerability profile across both doses

-- Detailed results to be presented at upcoming Clinical Trials on Alzheimer's Disease (CTAD) conference in November

-- Conference call and webcast to be held today at 8:00 a.m. Eastern Time

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 (mFAS1) 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.