Arena Pharmaceuticals, Inc.
Apr 13, 2005

Arena Pharmaceuticals to Announce First Quarter 2005 Financial Results on Tuesday, April 26, 2005, and to Host Conference Call and Webcast on Wednesday, April 27, 2005

SAN DIEGO, April 13 /PRNewswire-FirstCall/ -- Arena Pharmaceuticals, Inc. (Nasdaq: ARNA) today announced that the company will release its financial results for the first quarter of 2005, after the NASDAQ National Market closes on Tuesday, April 26, 2005. Arena also announced today that Jack Lief, President and Chief Executive Officer, will host a conference call to discuss the financial results from the first quarter of 2005 and to provide a corporate update. The call will take place on Wednesday, April 27, 2005, at 9:00 a.m. EDT (6:00 a.m. PDT).

The conference call may be accessed by dialing 888-396-2369 for domestic callers and 617-847-8710 for international callers. Please specify to the operator that you would like to join the "Arena First Quarter Earnings Call." The conference call will be webcast live under the investor relations section of Arena's website at http://www.arenapharm.com , and will be archived there for 30 days following the call. Please connect to Arena's website several minutes prior to the start of the conference call to ensure adequate time for any software download that may be necessary.

About Arena Pharmaceuticals

Arena is a clinical-stage biopharmaceutical company focusing on the discovery, development and commercialization of small molecule drugs in four major therapeutic areas: metabolic, cardiovascular, inflammatory and central nervous system diseases. Arena is developing a broad pipeline of compounds that act on an important class of drug targets called G protein-coupled receptors, or GPCRs, using its proprietary technologies, including CART (Constitutively Activated Receptor Technology) and Melanophore. Arena's most advanced clinical compound, APD356, a selective 5-HT2C serotonin receptor agonist for the treatment of obesity, is in a Phase 2 clinical trial. Arena is also conducting a Phase 1 clinical trial on APD125, a compound with a novel mechanism of action (a selective 5-HT2A receptor antagonist) for the treatment of insomnia. Arena has research collaborations with Ortho-McNeil Pharmaceutical, Inc., Merck & Co., Inc. and other companies for products in a number of different indications.

Forward-Looking Statements

Certain statements in this press release are forward-looking statements that involve a number of risks and uncertainties. Such forward-looking statements include statements about Arena's strategy, technologies, preclinical and clinical programs, and ability to develop compounds. For such statements, Arena claims the protection of the Private Securities Litigation Reform Act of 1995. Actual events or results may differ materially from Arena's expectations. Factors that could cause actual results to differ materially from the forward-looking statements include, but are not limited to, the timing, success and cost of Arena's research, out-licensing endeavors and clinical studies, Arena's ability to obtain additional financing, and the timing and receipt of payments and fees, if any, from Arena's collaborators, including Ortho-McNeil and Merck. Additional factors that could cause actual results to differ materially from those stated or implied by Arena's forward-looking statements are disclosed in Arena's filings with the Securities and Exchange Commission. These forward-looking statements represent Arena's judgment as of the time of this release. Arena disclaims any intent or obligation to update these forward-looking statements, other than as may be required under applicable law.

NOTE: Arena Pharmaceuticals® and Arena® are registered service marks of the company. CART is an unregistered service mark of the company.

SOURCE Arena Pharmaceuticals, Inc.
04/13/2005
CONTACT: Jack Lief, President and CEO, or David Walsey, Director, Corporate Communications, both of Arena Pharmaceuticals, Inc., +1-858-453-7200; or Media & Investor Relations, Susan Neath of Atkins + Associates, +1-858-527-3486, for Arena Pharmaceuticals, Inc.
Web site: http://www.arenapharm.com