Arena Pharmaceuticals to Present at Two Upcoming Investor Conferences

SAN DIEGO, June 4, 2010 /PRNewswire-FirstCall/ -- Arena Pharmaceuticals, Inc. announced today that Jack Lief, Arena's President and Chief Executive Officer, is scheduled to provide an overview of the company at two upcoming investor conferences in New York City:

-- Jefferies 2010 Global Life Sciences Conference ------------------------------------------------- Presentation: Wednesday, June 9, 2010, at 9:00 a.m. Eastern Time (6:00 a.m. Pacific Time) -- 9th Annual Needham Healthcare Conference ------------------------------------------- Presentation: Thursday, June 10, 2010, at 9:20 a.m. Eastern Time (6:20 a.m. Pacific Time)

A live audio webcast of each presentation will be available under the investor relations section of Arena's website at http://www.arenapharm.com/. A replay of each presentation will be available for 30 days following the event. Please connect to Arena's website several minutes prior to the start of the webcast to ensure adequate time for any software download that may be necessary.

About Arena Pharmaceuticals

Arena is a clinical-stage biopharmaceutical company focused on discovering, developing and commercializing oral drugs that target G protein-coupled receptors, an important class of validated drug targets, in four major therapeutic areas: cardiovascular, central nervous system, inflammatory and metabolic diseases. Arena's most advanced drug candidate, lorcaserin, is intended for weight management, including weight loss and maintenance of weight loss, and has completed a pivotal Phase 3 clinical trial program. Arena has filed an NDA for lorcaserin with the FDA, and the FDA has assigned a PDUFA date of October 22, 2010, for the review of the application.

Arena Pharmaceuticals(R) and Arena(R) are registered service marks of the company.

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 advancement, therapeutic indication, and regulatory review of lorcaserin; and Arena's focus, goals, strategy, research and development 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, regulatory authorities or advisors may not find data from Arena's clinical trials and other studies sufficient for regulatory approval; the timing and ability of Arena to receive regulatory approval for its drug candidates; the timing, success and cost of Arena's lorcaserin program and other of its research and development programs; results of clinical trials and other studies are subject to different interpretations and may not be predictive of future results; clinical trials and other studies may not proceed at the time or in the manner Arena or others expect or at all; Arena's ability to enter into agreements to develop or commercialize its compounds or programs; Arena's ability to commercialize lorcaserin with a pharmaceutical company or independently; Arena's ability to obtain adequate funds; 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.

Contact: Arena Pharmaceuticals, Inc. Media Contact: Russo Partners Jack Lief David Schull, President President and CEO [e-mail] 212.845.4271 Cindy McGee Manager, IR and Corporate Communications Anthony J. Russo, Ph.D., CEO 858.453.7200, ext. 1479 [e-mail] 212.845.4251

Arena Pharmaceuticals, Inc.

CONTACT: Jack Lief, President and CEO, or Cindy McGee, Manager, IR and
Corporate Communications, [phone], ext. 1479, both of Arena
Pharmaceuticals, Inc.; or David Schull, President, [phone],
[e-mail], or Anthony J. Russo, Ph.D., CEO,
[phone], [e-mail], both of Russo Partners, for
Arena Pharmaceuticals, Inc.

Web Site: http://www.arenapharm.com/