ACADIA Pharmaceuticals Inc. (NASDAQ: ACAD), a biopharmaceutical company focused on innovative treatments that address unmet medical needs in central nervous system disorders, today announced the initiation of ADVANCE, a Phase II study to evaluate pimavanserin for adjunctive treatment in patients with negative symptoms of schizophrenia. Studies show that about 40 to 50 percent of schizophrenia patients suffer from prominent negative symptoms. There is currently no drug approved by the U.S. Food and Drug Administration for the treatment of these negative symptoms. As a selective serotonin inverse agonist (SSIA), pimavanserin is a new class of antipsychotic medication with a distinct mechanism of action targeting serotonergic 5-HT 2A receptors while avoiding activity at dopamine and other receptors commonly targeted by other antipsychotics. "Currently available treatments do not adequately address negative symptoms of schizophrenia, which are highly prevalent and contribute significantly to the long term disability and functional impairment of people with this disease," said Serge Stankovic, M.D., M.S.P.H., ACADIA's Executive Vice President, Head of Research and Development. "With its highly selective pharmacological profile, we believe pimavanserin may address this unmet need and improve clinical outcomes for these patients." About ADVANCE ADVANCE is a Phase II, 26-week, randomized, double-blind, placebo-controlled, multi-center study designed to examine the efficacy and safety of adjunctive use of pimavanserin in patients with schizophrenia who have predominant negative symptoms. Approximately 380 patients will be randomized to receive either pimavanserin or placebo, orally, once daily, in addition to their ongoing antipsychotic in a flexible dosing regimen. The starting daily dose of 20 mg of pimavanserin at baseline may be adjusted to 34 mg or 10 mg during the first eight weeks of treatment. The primary endpoint of the study is the change from baseline to week 26 on the Negative Symptom Assessment-16 (NSA-16) total score. Following participation in ADVANCE, patients will be eligible to enroll in a 52-week open-label extension study.