ACADIA Pharmaceuticals Identifies Molecular Properties of ACP-104

ACADIA Pharmaceuticals Inc. has announced publication of research in the Journal of Pharmacology and Experimental Therapeutics, JPET, showing that ACP-104, the major metabolite of clozapine, is a partial agonist that causes weak activation of dopamine D2 and D3 receptors, whereas clozapine and most other antipsychotic drugs block these receptors. ACADIA believes that these partial agonist properties of ACP-104 may lead to less motoric side effects than seen with most other antipsychotic drugs. ACADIA is developing ACP-104 as a novel therapy for schizophrenia, with the added potential benefit of improving cognition.

The JPET article describes the research conducted by ACADIA scientists of 41 marketed and experimental antipsychotic drugs and their ability to alter the activities of dopamine D2, D3, and D4 receptors. Using ACADIA's proprietary R-SAT technology platform, the scientists developed assays that detect subtle changes in the activities of these receptors. Among the 41 drugs, only two of them, ACP-104 and aripiprazole, were partial agonists causing weak activation of dopamine D2 and D3 receptors. Most antipsychotic drugs were shown to block these dopamine receptors. Prior research has shown that blockade of the dopamine receptors may cause undesirable motoric side effects, including Parkinson-like symptoms and tardive dyskinesia.

ACP-104 is a small molecule drug candidate that ACADIA has discovered and is developing as a novel, stand-alone therapy for schizophrenia. It combines an atypical antipsychotic efficacy profile with the added potential benefit of improving cognition, one of the major challenges in treating schizophrenia today. ACP-104, or N-desmethylclozapine, is the major metabolite of clozapine, and has a unique ability to stimulate M1 muscarinic receptors. The M1 muscarinic receptors are widely known to play an important role in cognition.

ACADIA Pharmaceuticals Inc. is a biopharmaceutical company utilizing innovative technology to fuel drug discovery and clinical development of novel treatments for CNS disorders. ACADIA currently has four drug programs in clinical development as well as a portfolio of preclinical and discovery assets directed at large unmet medical needs, including schizophrenia, Parkinson's disease, neuropathic pain, and glaucoma. Using its proprietary drug discovery platform, ACADIA has discovered all of the drug candidates in its product pipeline. ACADIA's corporate headquarters is located in San Diego, California and it maintains research and development operations in both San Diego and Medeon Science Park, Sweden.

For further information please contact:

Bo-Ragner Tolf,

Vice President

Tel: +45 43 29 30 00

Email: btolf@acadia-pharm.com

Or visit: www.acadia-pharm.com