European health regulator raises concerns over Arena obesity drug

Jan 22 (Reuters) - Arena Pharmaceuticals Inc said the European health regulator had raised concerns with the company's obesity drug, Belviq, sending its shares down as much as 10 percent.

The European Medicines Agency's Committee for Medicinal Products for Human Use (CHMP) raised objections related to issues such as tumors in rats, heart valve disorders and psychiatric events, Arena said in a regulatory filing on Tuesday. (http://r.reuters.com/hym45t)

"The CHMP requests that we further justify Belviq's overall benefit-risk balance taking these issues into consideration," the San Diego, California-based company said.

Arena said it expects the regulator to make a final decision on Belviq in the first half of 2013. Belviq is designed to block appetite signals in the brain to help people feel full after eating smaller amounts of food.

The U.S. Food and Drug Administration had raised similar concerns over Belviq before eventually approving the drug in June 2012.

Arena had at that time argued that the incidence of tumors was specific to rodents and humans have different biological mechanisms.

The FDA's main concern though was Belviq's impact on heart valves, which could signal broader cardiac damage.

Post approval, the FDA directed Arena to conduct six follow-up studies, including a long-term study of whether Belviq increases the risk of heart attack or stroke.

Arena's shares fell 8 percent to $8.98 in mid-day trade on the Nasdaq.

(Reporting By Pallavi Ail in Bangalore; Editing by Supriya Kurane)