Arena Pharmaceuticals Prices Public Offering of Common Stock

Arena Pharmaceuticals announced the pricing of an underwritten public offering of 11,000,000 shares of its common stock, offered at a price to the public of $5.50 per share. The gross proceeds to Arena from this offering are expected to be $60.5 million, before deducting underwriting discounts and commissions and other estimated offering expenses payable by Arena. Arena has granted the underwriters a 30-day option to purchase up to an aggregate of 1,650,000 additional shares of common stock to cover over-allotments, if any. The offering is expected to close on or about May 21, 2012, subject to customary closing conditions. Arena anticipates using the net proceeds from the offering for general corporate purposes, which may include expenses related to the commercialization of lorcaserin, if approved, as well as for research and development expenses, capital expenditures, working capital, and general and administrative expenses. Jefferies & Company, Inc. and Piper Jaffray & Co. are acting as joint book-running managers for the offering. BMO Capital Markets is acting as a co-manager for the offering.