NEW YORK, NY--(Marketwire - September 20, 2010) - Kaplan Fox & Kilsheimer LLP (www.kaplanfox.com) has filed a class action suit against Arena Pharmaceuticals, Inc. ("Arena" or the "Company") (NASDAQ: ARNA) that alleges violations of the Securities Exchange Act of 1934 and the Securities Act of 1933 on behalf of purchasers of Arena securities during the period May 11, 2009 and September 16, 2010 inclusive, including investors who purchased Arena shares in the Company's public offerings of common stock during the Class Period (the "Class").