Kaplan Fox & Kilsheimer LLP has filed a class action suit against Arena Pharmaceuticals, Inc. 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").

The case is pending in the United States District Court for the Southern District of California. A copy of the complaint may be obtained from Kaplan Fox or the Court. The Complaint alleges that throughout the Class Period the Company represented to investors that the New Drug Application ("NDA") for its drug lorcaserin, or Lorqess, was based on extensive and robust data, and, that lorcaserin's combination of efficacy, safety and tolerability would position the drug candidate as first-line therapy for weight management.

The Complaint further alleges that on September 14, 2010, investors began to learn the truth about lorcaserin when the FDA disclosed a Briefing Document titled NDA 22529 Lorqess (lorcaserin hydrochloride) Tablets, 10 mg Sponsor: Arena Pharmaceuticals Advisory Committee - September 16, 2010, which revealed, among other things, that lorcaserin caused cancer in rats in certain preclinical studies.

On September 14, 2010, Arena shares declined from a close on September 13, 2010 of $6.85 per share, to close at $4.13 per share, a decline of $2.71 per share or approximately 40%. On September 16, 2010, the Wall Street Journal reported a federal advisory panel rejected lorcaserin. On September 17, 2010, Arena shares declined an additional $1.99 per share or approximately 47%.

If you are a member of the proposed Class, you may move the court no later than November 19, 2010 to serve as a lead plaintiff for the Class. You need not seek to become a lead plaintiff in order to share in any possible recovery.

Plaintiff seeks to recover damages on behalf of the Class and is represented by Kaplan Fox & Kilsheimer LLP. Our firm, with offices in New York, San Francisco, Los Angeles, Chicago and New Jersey, has many years of experience in prosecuting investor class actions and actions involving fraud. For more information about Kaplan Fox & Kilsheimer LLP, or to review a copy of the complaint filed in this action, you may visit our website at www.kaplanfox.com.