ACADIA Pharmaceuticals Announces $86 Million Equity Financing

—Proceeds to Support Completion of Pimavanserin Phase IIIProgram—

SAN DIEGO—(BUSINESS WIRE)—Dec. 12, 2012—ACADIA Pharmaceuticals Inc. (NASDAQ: ACAD) a biopharmaceutical companyfocused on innovative treatments that address unmet medical needs inneurological and related central nervous system disorders, todayannounced a private placement equity financing pursuant to which ACADIAwill receive gross proceeds of $86.4 million from the sale of itssecurities. Shares of ACADIA’s common stock will be sold at $4.43 pershare, the closing market price on December 11, 2012. The privateplacement is expected to close on December 17, 2012 and is subject tothe satisfaction of customary closing conditions.

The anticipated proceeds from the private placement will be usedprimarily to support completion of ACADIA’s Phase III pimavanserinprogram, including its planned confirmatory Phase III pivotal trial inParkinson’s disease psychosis.

Jefferies & Company, Inc. and Cowen and Company, LLC acted as joint leadplacement agents; JMP Securities LLC acted as co-placement agent in thetransaction.

This press release shall not constitute an offer to sell or thesolicitation of an offer to buy these securities, nor shall there be anysale of these securities in any jurisdiction in which such offer,solicitation or sale would be unlawful prior to the registration orqualification under the securities laws of any such jurisdiction.

The securities being sold in the private placement have not beenregistered under the Securities Act of 1933, as amended, or statesecurities laws and may not be offered or sold in the United Statesabsent registration with the Securities and Exchange Commission (“SEC”)or an applicable exemption from such registration requirements. ACADIAhas agreed to file a registration statement with the SEC covering theresale of the shares of common stock issuable in connection with theprivate placement.

About ACADIA Pharmaceuticals

ACADIA is a biopharmaceutical company focused on innovative treatmentsthat address unmet medical needs in neurological and related centralnervous system disorders. ACADIA has a pipeline of product candidatesled by pimavanserin, which is in Phase III development as a potentialfirst-in-class treatment for Parkinson's disease psychosis. ACADIA alsohas clinical-stage programs for chronic pain and glaucoma incollaboration with Allergan, Inc. and two advanced preclinical programsdirected at Parkinson’s disease and other neurological disorders. Allproduct candidates are small molecules that emanate from discoveriesmade at ACADIA. ACADIA maintains a website at www.acadia-pharm.comto which ACADIA regularly posts copies of its press releases as well asadditional information and through which interested parties cansubscribe to receive email alerts.

Forward-Looking Statements

Statements in this press release that are not strictly historical innature are forward-looking statements. These statements include but arenot limited to statements related to the progress and timing of ACADIA’sdrug discovery and development programs, either alone or with a partner,including the progress of clinical trials, and the clinical benefits tobe derived from ACADIA’s product candidates, in each case includingpimavanserin. In particular, forward-looking statements includestatements regarding the expected proceeds from and timing of theclosing of the private placement, the use of proceeds from the privateplacement, including whether the proceeds will be sufficient to fund thecompletion of the Phase III program for pimavanserin, including theplanned confirmatory Phase III pivotal trial, and the anticipated filingof a registration statement to cover resales of common stock issuable inconnection with the private placement. These statements are onlypredictions based on current information and expectations and involve anumber of risks and uncertainties. Actual events or results may differmaterially from those projected in any of such statements due to variousfactors, including the risks and uncertainties inherent in drugdiscovery, development, regulatory review and commercialization,including in collaborations with others, the fact that past results ofclinical trials may not be indicative of future trial results, andACADIA’s ability to satisfy the conditions to closing the privateplacement. For a discussion of these and other factors, please refer toACADIA’s annual report on Form 10-K for the year ended December 31, 2011as well as ACADIA’s subsequent filings with the Securities and ExchangeCommission. You are cautioned not to place undue reliance on theseforward-looking statements, which speak only as of the date hereof. Thiscaution is made under the safe harbor provisions of the PrivateSecurities Litigation Reform Act of 1995. All forward-looking statementsare qualified in their entirety by this cautionary statement and ACADIAundertakes no obligation to revise or update this press release toreflect events or circumstances after the date hereof, except asrequired by law.

Source: ACADIA Pharmaceuticals Inc.

ACADIA Pharmaceuticals Inc.
Thomas H. Aasen, ExecutiveVice President,
Chief Financial Officer and Chief BusinessOfficer
858-558-2871