ANTI-OBESITY AGENT LORCASERIN RECEIVES POSITIVE VOTE FROM FDA ADVISORY COMMITTEE

Eisai Co., Ltd. (Headquarters: Tokyo, President & CEO: Haruo Naito, “Eisai”) announced today that the U.S. Food and Drug Administration (FDA) Endocrinologic and Metabolic Drugs Advisory Committee voted 18 to 4, with 1 abstention, at a meeting held on May 10, 2012 (local U.S. time) that the available data adequately demonstrate that the potential benefits of the anti-obesity agent lorcaserin outweigh the potential risks when used long-term in a population of overweight and obese individuals. Currently under regulatory review in the United States, lorcaserin is an investigational drug candidate that was discovered and is being developed by U.S.-based Arena Pharmaceuticals, Inc. (Headquarters: California, President & CEO: Jack Lief, “Arena”).

Lorcaserin is intended for weight management, including weight loss and maintenance of weight loss, in patients who are obese (BMI≥30) or patients who are overweight (BMI≥27) and have at least one weight-related co-morbid condition. Lorcaserin in the subject of an exclusive U.S. marketing and supply agreement concluded between Eisai’s U.S. subsidiary Eisai Inc. and Arena Pharmaceuticals GmbH, the wholly-owned Swiss subsidiary of Arena.

According to the U.S. Centers for Disease Control and Prevention, two thirds of American adults are overweight or obese. Furthermore, the prevalence of obesity in the United States more than doubled (from approx. 15% to approx. 36%) among adults from 1980 to 2010.

The results of the vote mean that the advisory committee supports lorcaserin as a potential new treatment option for the medical management of overweight and obese patients. Although advisory committees provide recommendations to the FDA, the agency makes the final decisions regarding approval. The Prescription Drug User Fee Act (PDUFA) date for the lorcaserin New Drug Application (NDA) resubmission is June 27, 2012, which is the target date for the agency to complete its review.

[ Please refer to the following notes for further information on lorcaserin and Arena Pharmaceuticals, Inc. ]

Lorcaserin, discovered and developed by Arena, is a new chemical entity that is believed to act as a selective serotonin 2C (5-HT2C) receptor agonist. The serotonin 2C receptor is expressed in the brain, including the hypothalamus, an area believed to be involved in the control of appetite and metabolism. Stimulation of this receptor is strongly associated with reducing hunger and increasing satiety.

Arena Pharmaceuticals, Inc. is a clinical-stage biopharmaceutical company focused on discovering, developing and commercializing oral drugs that target G protein-coupled receptors, an important class of validated drug targets, in four major therapeutic areas: cardiovascular, central nervous system, inflammatory and metabolic diseases.
Arena Pharmaceuticals® and Arena® are registered service marks of the company.