ACADIA Pharmaceuticals Initiates Phase IIb Clinical Trial with ACP-104

ACADIA Pharmaceuticals Inc. has announced the initiation of a Phase IIb clinical trial designed to evaluate the safety and efficacy of ACP-104 as a treatment for patients with schizophrenia.

The Phase IIb trial is a multi-centre, double-blind, placebo-controlled study designed to evaluate the safety and efficacy of ACP-104 in approximately 250 patients with schizophrenia who are experiencing an acute psychotic episode. Patients in the trial will be randomized to three different study arms, including two different doses of ACP-104, 100 mg twice daily and 200 mg twice daily, and one placebo arm. Patients will receive oral doses of either ACP-104 or placebo for six weeks. The primary endpoint of the trial is antipsychotic efficacy as measured using the Positive and Negative Syndrome Scale, or PANSS, an industry standard rating scale commonly used in schizophrenia trials.

ACP-104 or N-desmethylclozapine is the major metabolite of clozapine that ACADIA is developing as a novel stand-alone therapy for schizophrenia. ACP-104 is designed to provide an atypical antipsychotic efficacy profile with the added potential benefit of enhanced cognition.

For further information please contact:

Bo-Ragner Tolf,

Vice President

Tel: +46 40 601 34 00

Email: btolf@acadia-pharm.com

Or visit www.acadia-pharm.com