NEW YORK, NY--(Marketwire - September 21, 2010) - On September 21, 2010, the law firm of Sarraf Gentile LLP commenced a securities fraud class action lawsuit on behalf of those investors who acquired the securities of Arena Pharmaceuticals, Inc. ("Arena" or the "Company") (NASDAQ: ARNA) during the period March 30, 2009 to September 17, 2010, inclusive (the "Class Period"). The lawsuit is pending in the United States District Court for the Southern District of California and names as defendants Arena and certain of its top officers.