Arena Pharmaceuticals, Inc.
Aug 31, 2004

Webcast Alert: Arena Pharmaceuticals Presentation at Informed Investors Healthcare Virtual Stocks Forum to be Webcast on Tuesday, August 17, 2004, 10:00 AM ET (7:00 AM PT)

SAN DIEGO, Aug. 13 /PRNewswire/ -- Arena Pharmaceuticals (Nasdaq: ARNA) will present a corporate update at the following forum:

    What:    Arena Pharmaceuticals will give a presentation at Informed
             Investors Healthcare Virtual Stocks Forum

             Robin R. Young, CFA, Managing Director, Research Healthpoint
             Group, will deliver forum keynote at 9:00 AM Eastern Time
             (6:00 AM Pacific Time)

    When:    Arena will present on August 17, 2004 at 10:00 AM Eastern Time (7:00 AM Pacific Time)

    Where:   http://www.informedinvestors.com/IIF_Forum.asp?ForumID=88540 or
             on the Arena website at http://www.arenapharm.com under the
             "Investor Relations" section

    How:     Over the Internet-Simply log on to one of the web addresses above

Contact: Jack Lief, President and CEO of Arena, at 858-453-7200 or jlief@arenapharm.com

If you are unable to attend the original broadcast, the forum will be available via an archived webcast at http://www.informedinvestors.com/IIF_Forum.asp?ForumID=88540 or http://www.arenapharm.com under the "Investor Relations" section. The archive will be available for 30 days following the original broadcast.

About Arena

Arena is a clinical stage biopharmaceutical company focusing on the discovery, development and commercialization of 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, and that are being developed using Arena's proprietary technologies, including CART (Constitutively Activated Receptor Technology) and Melanophore. Arena also has research collaborations with Merck, Fujisawa, Taisho and TaiGen for products in a number of different indications. For additional information about Arena, visit their website at http://www.arenapharm.com.

FORUM CONTACT: Cary Loeser, Informed Investors, 804-327-3407, cloeser@wilink.com

Website: http://www.informedinvestors.com

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, ability to identify and develop drugs, future achievements, goals and expectations, as well as other statements that are not historical facts. 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. 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 SEC reports, including Arena's most recent quarterly report on Form 10-Q. These forward-looking statements represent Arena's judgment as of the date of this release. Arena disclaims any intent or obligation to update these forward-looking statements.

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

SOURCE Arena Pharmaceuticals
08/13/2004
CONTACT: Jack Lief, President and CEO of Arena, +1-858-453-7200, jlief@arenapharm.com; or Cary Loeser of Informed Investors, +1-804-327-3407, cloeser@wilink.com
Web site: http://www.informedinvestors.com/IIF_Forum.asp?ForumID=88540
http://www.arenapharm.com
http://www.informedinvestors.com