ACADIA ANNOUNCES ACP-103 TRIAL RESULTS

Acadia has reported results from a planned interim trend analysis of its ongoing multicenter Phase II clinical trial of ACP-103 for treatment-induced psychosis in patients with Parkinson's disease.

Results of the interim analysis demonstrated that the ACP-103 treatment group showed a greater reduction in psychotic symptoms on both rating scales, relative to the placebo treatment group. Only two patients dropped from the study, one on placebo and one on ACP-103. No serious adverse events were reported.

The interim findings are limited to trends relative to the trial's endpoints of efficacy and are not necessarily indicative of the trial's final results. Acadia is continuing to enroll patients in the study and expects to report results from a complete statistical analysis of all clinical endpoints on all 60 patients in late-2005 or early-2006.