SAN DIEGO, July 7, 2009 /PRNewswire-FirstCall/ -- Arena Pharmaceuticals, Inc. (Nasdaq: ARNA) announced today that it intends to offer shares of its common stock in a public offering. Piper Jaffray & Co. will be the sole underwriter for the offering. The offering is being made pursuant to a shelf registration statement filed with the Securities and Exchange Commission on November 25, 2008, which became effective on December 3, 2008. A prospectus supplement relating to the offering will be filed with the Securities and Exchange Commission.

This press release shall not constitute an offer to sell or the solicitation of an offer to buy, nor shall there be any sale of, these securities in any state or other jurisdiction in which such offer, solicitation or sale would be unlawful prior to the registration or qualification under the securities laws of any such state or jurisdiction. When available, copies of the prospectus supplement relating to this offering may be obtained by contacting Piper Jaffray & Co. by mail at 800 Nicollet Mall, Suite 800, Minneapolis, MN 55402 or by telephone at 800.747.3924.

    Contact:  Jack Lief
              President and CEO
              Robert E. Hoffman
              VP, Finance and CFO
              Arena Pharmaceuticals, Inc.
              858.453.7200, ext. 222

www.arenapharm.com

SOURCE Arena Pharmaceuticals, Inc.