ACADIA Pharmaceuticals Inc. (NASDAQ: ACAD), a biopharmaceutical company focused on innovative treatments that address unmet medical needs in neurological and related central nervous system disorders, today announced the completion of enrollment in its ongoing pivotal Phase III trial with pimavanserin in patients with Parkinson’s disease psychosis (PDP). Top-line results from this trial are expected to be announced by the end of November 2012. The Phase III trial, referred to as the -020 Study, is a multi-center, double-blind, placebo-controlled study designed to evaluate the efficacy, tolerability and safety of pimavanserin as a treatment for patients with PDP. The -020 Study incorporates several design enhancements that were guided by previous data in ACADIA’s PDP program. A total of 198 patients have been enrolled in the study and were randomized on a one-to-one basis to receive either 40 mg of pimavanserin or placebo once-daily for six weeks. The primary endpoint of the -020 Study is antipsychotic efficacy as measured using nine items from the hallucinations and delusions domains of the Scale for the Assessment of Positive Symptoms, or SAPS. An independent group of centralized raters is used to assess the primary endpoint in the study. Motoric tolerability is a key secondary endpoint in the study and is measured using Parts II and III of the Unified Parkinson’s Disease Rating Scale, or UPDRS. About Pimavanserin Pimavanserin is ACADIA’s proprietary small molecule that acts selectively as an antagonist/inverse agonist on serotonin 5-HT 2A receptors and is in Phase III development as a potential first-in-class treatment for Parkinson’s disease psychosis. Pimavanserin can be taken orally as a tablet once-a-day. ACADIA discovered and holds worldwide rights to pimavanserin. About Parkinson’s Disease Psychosis According to the National Parkinson’s Foundation, about one million people in the United States and from four to six million people worldwide suffer from Parkinson’s disease. Parkinson’s disease psychosis, or PDP, is a debilitating disorder that develops in up to 60 percent of patients with Parkinson’s disease. Currently, there is no FDA-approved therapy to treat PDP in the United States. PDP, commonly consisting of visual hallucinations and delusions, substantially contributes to the burden of Parkinson’s disease and deeply affects the quality of life of patients. PDP is associated with increased caregiver stress and burden, nursing home placement, and increased morbidity and mortality. There is a large unmet medical need for new therapies that will effectively treat PDP without compromising motor control in patients with Parkinson’s disease.