EISAI EXPANDS MARKETING AND SUPPLY AGREEMENT FOR ANTIOBESITY AGENT LORCASERIN TO INCLUDE MOST COUNTRIES WORLDWIDEAIMS TO ESTABLISH WEIGHT MANAGEMENT GLOBAL STANDARD THAT INCLUDES DRUG THERAPY

Eisai Co., Ltd. (Headquarters: Tokyo, President & CEO: Haruo Naito, “Eisai”) announced today that it has expanded the marketing and supply agreement it concluded with Arena Pharmaceuticals, Inc. (Headquarters: California, United States; President & CEO: Jack Lief, “Arena”) in July 2010 for the antiobesity agent lorcaserin hydrochloride (U.S. brand name: BELVIQ®; “lorcaserin”). While the previous agreement granted Eisai exclusive rights to market and distribute lorcaserin in 21 countries throughout the Americas, the expanded agreement now includes most countries and territories worldwide, most notably the European Union, Japan and China (and excluding South Korea, Taiwan, Australia, New Zealand, Israel).

Under this agreement, Eisai will be working in collaboration with Arena to develop and seek approval of lorcaserin as an antiobesity treatment in multiple eligible countries and territories worldwide. In addition to pursuing regulatory approval for weight management in the expanded territories, Eisai and Arena plan to investigate the potential of lorcaserin in new areas, such as smoking cessation, a once-daily formulation, a fixed-dose combination with phentermine, as well as explore lorcaserin's impact on diabetes and cardiovascular outcomes. Eisai's commercialization rights are subject to applicable regulatory approval.

BELVIQ is approved in the United States by the U.S. Food and Drug Administration (FDA) as an adjunct to a reduced-calorie diet and increased physical activity for chronic weight management in adult patients with an initial body mass index (BMI) of 30 kg/m2or greater, or 27 kg/m2or greater in the presence of at least one weight-related co-morbid condition. The drug has been marketed in the U.S. by Eisai's U.S. subsidiary, Eisai Inc. Marketing authorization has also been applied for in Mexico and Canada.

In recent years, obesity has become a major global health problem, with more than 1.4 billion adults worldwide believed to be overweight and approximately 500 million of that number qualifying as obese. Following the expansion of this license agreement, the Eisai Group seeks to provide a new treatment option for obesity in each country and territory while seeking to establish a weight management global standard that includes drug therapy so as to further contribute to increasing the benefits provided to patients and their families.

[ Please refer to the following notes for further information on BELVIQ and overweight and obesity worldwide. ]

Media Inquiries:

Public Relations Department,
Eisai Co., Ltd.
+81-(0)3-3817-5120

< Notes to editors >

1. About BELVIQ® (lorcaserin hydrochloride)

Discovered and developed by Arena Pharmaceuticals, Inc., BELVIQ is a new chemical entity that is believed to decrease food consumption and promote satiety by selectively activating serotonin 2C receptors in the brain. Activation of these receptors may help a person eat less and feel full after eating smaller amounts of food. BELVIQ is approved by the U.S. Food and Drug Administration (FDA) as an adjunct to a reduced-calorie diet and increased physical activity for chronic weight management in adult patients with an initial body mass index (BMI) of 30 kg/m2or greater (obese) or 27 kg/m2or greater (overweight) in the presence of at least one weight-related co-morbid condition. The use of BELVIQ in combination with other products for weight loss and its effectiveness on cardiovascular morbidity and mortality have not been established. BELVIQ was launched in the United States in June 2013 after receiving a final scheduling designation from the U.S. Drug Enforcement Administration (DEA). For further information on BELVIQ, including important safety information (ISI), please visit the BELVIQ product website ( http://www.belviq.com).

2. About Worldwide Overweight and Obesity

In recent years, obesity has become a major global health problem, with more than 1.4 billion adults worldwide believed to be overweight and approximately 500 million of that number qualifying as obese. By region, around 170 million people in the United States and 150 million people in Europe are reported to fall into one or both categories, while in Asia, the overweight and obese population includes an estimated 100 million people in China and a further 25 million people in Japan.