Arena Pharmaceuticals Announces Public Offering of Common Stock

SAN DIEGO, Oct. 19 /PRNewswire-FirstCall/ -- Arena Pharmaceuticals, Inc. announced today that it has filed a preliminary prospectus supplement to a shelf registration statement with the Securities and Exchange Commission relating to a proposed public offering of 10,000,000 shares of its common stock. In connection with this offering, Arena plans to grant to the underwriters a 30-day option to purchase up to an additional 1,500,000 shares of common stock to cover over-allotments, if any. All of the shares are being offered by Arena. CIBC World Markets and UBS Investment Bank are acting as joint book-running managers in this offering.

The securities may not be sold nor may offers to buy be accepted prior to the time that a final prospectus supplement is 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 jurisdiction in which such offer, solicitation or sale would be unlawful prior to the registration or qualification under the securities laws of any such jurisdiction. Copies of the preliminary prospectus may be obtained from CIBC World Markets by email at [e-mail], by phone at 212.667.7200, by fax at 212.667.6303, or by mail at CIBC World Markets, Attn: USE Prospectus Department, 425 Lexington Avenue, 5th floor, New York, NY 10017, or from UBS Investment Bank, Prospectus Department, 299 Park Avenue, 8th floor, New York, NY 10171 or by phone at 888.827.7275.

Contacts: Jack Lief Mary Claire Duch President and CEO WeissComm Partners Media Relations David Walsey 212.301.7228 Director, Corporate Communications Arena Pharmaceuticals, Inc. 858.453.7200, ext. 1682 http://www.arenapharm.com/