Arena Pharmaceuticals, Inc.
Feb 8, 2006

Arena Pharmaceuticals to Present at the BIO CEO & Investor Conference on Tuesday, February 14, 2006

SAN DIEGO, Feb. 8 /PRNewswire-FirstCall/ -- Arena Pharmaceuticals, Inc. (Nasdaq: ARNA) announced today that it will present at the BIO CEO & Investor Conference on Tuesday, February 14, 2006, at 2:30 p.m. Eastern Time (11:30 a.m. Pacific Time) at the Waldorf Astoria, New York, New York. Louis J. Scotti, Arena's Vice President, Marketing and Business Development, will provide a corporate overview and update of Arena and its clinical development and discovery programs.

A live audio webcast of the presentation will be available under the investor relations section of Arena's website at www.arenapharm.com. Replays of the presentation will be available for 30 days following the event. Please connect to Arena's website several minutes prior to the start of the broadcast 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, central nervous system, cardiovascular and inflammatory diseases. Arena is developing a broad pipeline of compounds targeting an important class of drug targets called G protein-coupled receptors, or GPCRs, using its knowledge of GPCRs and its technologies, including CART (Constitutively Activated Receptor Technology) and Melanophore. Arena has four internally discovered, clinical-stage drug candidates for major diseases. The most advanced is APD356, a selective 5-HT2C serotonin receptor agonist under investigation for the treatment of obesity that is expected to enter Phase 3 clinical development in the second half of 2006. Arena's lead drug candidate for the treatment of insomnia, APD125, is a compound with a novel mechanism of action (a selective 5-HT2A receptor inverse agonist) that is expected to enter Phase 2 clinical development in the first quarter of 2006. Arena also has two clinical-stage collaborations with major pharmaceutical companies. As part of its collaboration with Merck & Co., Inc., Merck began a Phase 1 clinical trial of an Arena-discovered drug candidate for the treatment of atherosclerosis and related disorders in the third quarter of 2005, and, as part of its collaboration with Ortho-McNeil, Inc., a Johnson & Johnson company, Ortho-McNeil began a Phase 1 clinical trial of APD668, an Arena-discovered drug candidate for the treatment of type 2 diabetes in February 2006.

Arena Pharmaceuticals® and Arena® are registered service marks of the company. CART is an unregistered service mark of the company. "APD" is an abbreviation for Arena Pharmaceuticals Development.

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 the timing of the expected Phase 2 clinical trial of APD125 and the expected Phase 3 clinical trial of APD356, and other statements about Arena's strategy, technologies, preclinical and clinical programs, and ability to develop compounds and commercialize drugs. 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 FDA may not allow the Phase 2 clinical trial of APD125 to proceed at the time Arena expects or at all, the results of preclinical studies or clinical trials may not be predictive of future results, Arena's ability to partner APD356, APD125 or other of its compounds or programs, the timing, success and cost of Arena's research, out-licensing endeavors and clinical trials, Arena's ability to obtain additional financing, Arena's ability to obtain and defend its patents, and the timing and receipt of payments and fees, if any, from Arena's collaborators. 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.

SOURCE Arena Pharmaceuticals, Inc.

CONTACT: Jack Lief, President and CEO, or David Walsey, Director, Corporate Communications, both of Arena Pharmaceuticals, Inc., +1-858-453-7200, ext. 1682; or Media & Investor Relations, Carin Canale of Porter Novelli Life Sciences, +1-858-527-3498, for Arena Pharmaceuticals, Inc.
Web site: http://www.arenapharm.com