ACADIA Pharmaceuticals to Present Preclinical Data on ACP-104, ACP-105 and Its Muscarinic Discovery Program at Experimental Biology 2008 Meeting.

SAN DIEGO -- ACADIA Pharmaceuticals Inc. (Nasdaq: ACAD), a biopharmaceutical company utilizing innovative technology to fuel drug discovery and clinical development of novel treatments for central nervous system disorders, today announced that the company will present preclinical data on its ACP-104 schizophrenia program, its ACP-105 Selective Androgen Receptor Modulator (SARM) program, and its muscarinic discovery program at the Experimental Biology 2008 Meeting to be held from April 5-9, 2008 in San Diego, California, and the related Satellite Symposium on Recent Advances in Muscarinic Receptor Pharmacology and Therapeutics to be held from April 4-5, 2008.

ACP-104's Pro-cognitive and Antipsychotic Actions in Animal Models are Based on Simultaneous Interactions with M1, 5-HT2A, and D2 Receptors

In poster presentations titled, "ACP-104 is a Unique Atypical Antipsychotic Agent with M1 Muscarinic Activity" and "In Vivo Receptor Occupancy of ACP-104 and Clozapine," ACADIA researchers present new preclinical data on ACP-104, its novel drug candidate currently in Phase II development for the treatment of schizophrenia. The data show that ACP-104 demonstrates pro-cognitive actions in an animal model by a muscarinic M1 receptor dependent mechanism. ACADIA researchers also show that ACP-104 interacts with M1, 5-HT2A, and D2 receptors in vivo at doses that are effective in animal models of psychosis and cognition. In addition, the combined antagonism at 5-HT2A and partial agonism at D2 receptors in vivo suggests ACP-104 may produce antipsychotic activity with reduced extrapyramidal side effects. Furthermore, the findings that ACP-104 binds to and activates M1 receptors in vivo support the potential utility of ACP-104 as a pro-cognitive antipsychotic in the treatment of schizophrenia.

ACP-105, a Novel Non-Steroidal SARM

In a poster presentation titled, "In Vitro and In Vivo Profile of a Novel Tissue Selective, Orally Bioavailable Non-Steroidal Androgen Receptor Modulator," ACADIA researchers present findings on ACP-105, a novel non-steroidal SARM. ACP-105 is shown to be as potent and efficacious as testosterone in in vitro assays without interaction at other hormone receptors. In addition, ACP-105 demonstrates potent anabolic effects on muscle and bone with minimal effect on prostrate in preclinical models.

AC-260584, a Novel and Selective Muscarinic M1 Agonist

In poster presentations titled, "Characterization of the Intrinsic Efficacies of M1 Muscarinic Receptor Agonists" and "Pharmacological Characterization of AC-260584, a Potent and Selective M1 Muscarinic Receptor Agonist," ACADIA researchers describe the pharmacology of a novel, potent, and selective muscarinic M1 receptor subtype agonist. AC-260584 activates muscarinic M1 receptors in the brain and also has pro-cognitive actions in animal models. Further studies using a range of in vitro techniques reveal notable differences in the intrinsic activities of muscarinic M1 receptor agonists and demonstrate that allosteric agonists such as AC-260584 can have high intrinsic activity at muscarinic M1 receptors.

About ACP-104

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. ACP-104 combines M1 muscarinic agonism, 5-HT2A inverse agonism, and D2 and D3 dopamine partial agonism in a single compound and, therefore, uniquely addresses what ACADIA believes are the three most promising target mechanisms for treating schizophrenia. ACADIA has completed enrollment in a Phase IIb trial to evaluate the safety and efficacy of ACP-104 in patients with schizophrenia. ACADIA's development program for ACP-104 has been supported in part by the Stanley Medical Research Center.

About ACP-105

ACP-105 is a non-steroidal and selective androgen receptor agonist. ACP-105 is part of a class of molecules referred to as selective androgen receptor modulators (SARMs). SARMs may advance the standard of treatment for a variety of disorders including muscle-wasting conditions and osteoporosis, with fewer side effects as compared to current treatments based on testosterone replacement. ACP-105 has exhibited promising pharmacological properties and a favorable safety profile in preclinical testing.

About ACADIA Pharmaceuticals

ACADIA is a biopharmaceutical company utilizing innovative technology to fuel drug discovery and clinical development of novel treatments for central nervous system disorders. ACADIA currently has five mid-to-late stage clinical programs as well as a portfolio of preclinical and discovery assets directed at diseases with large unmet medical needs, including schizophrenia, Parkinson's disease psychosis, sleep maintenance insomnia, and neuropathic pain. All of the drug candidates in ACADIA's product pipeline emanate from discoveries made using its proprietary drug discovery platform. ACADIA's corporate headquarters is located in San Diego, California and it maintains research and development operations in both San Diego and Malmo, Sweden.

Forward-Looking Statements

Statements in this press release that are not strictly historical in nature are forward-looking statements. These statements include but are not limited to statements related to benefits to be derived from ACADIA's preclinical and drug development programs, including the potential advantages of the use of ACP-104 as a stand-alone treatment for schizophrenia, including pro-cognitive benefits, the use of ACP-105 as a treatment for bone and muscle wasting with minimal side effects, and the use of AC-260594 to activate M1 receptors and provide cognitive benefits. These statements are only predictions based on current information and expectations and involve a number of risks and uncertainties. Actual events or results may differ materially from those projected in any of such statements due to various factors, including the risks and uncertainties inherent in clinical trials, and drug development and commercialization, including the uncertainty of whether results in clinical testing of ACP-104 to date will be predictive of results in later stages of development and whether preclinical testing of ACP-104, ACP-105 and AC-260584 in animal models will be predictive of results in later stages of development. For a discussion of these and other factors, please refer to ACADIA's annual report on Form 10-K for the year ended December 31, 2007 as well as other subsequent filings with the Securities and Exchange Commission. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof. This caution is made under the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. All forward-looking statements are qualified in their entirety by this cautionary statement and ACADIA undertakes no obligation to revise or update this press release to reflect events or circumstances after the date hereof.