Patent Litigators Secure Final Victory for Eisai Against Generic Drugmakers

July 22, 2008

New York, NY (July 22, 2008) Paul, Hastings, Janofsky & Walker LLP, a leading international law firm, announced today that the U.S. Court of Appeals for the Federal Circuit has upheld district court decisions won on behalf of Eisai Co., Ltd. and its over a billion dollar a year stomach acid suppression medication, Aciphex (R).

The ruling affirmed a decision from the U.S. District Court in the Southern District of New York in May 2007, finding after trial that Eisai's patent on Aciphex's active ingredient, rabeprazole, was enforceable, and thwarted attempts by Teva Pharmaceuticals and Dr. Reddy's Laboratories to sell generic versions of the drug in the U.S. prior to the expiration of Eisai's patent in 2013.

The generic drugmakers had charged that Eisai's patent should be held unenforceable because Eisai had allegedly failed to disclose a copending patent application covering a drug molecule that was almost identical to the active ingredient of Aciphex. This failure was alleged to have been done with the intent to deceive the Patent Office.

The Federal Circuit also upheld the district court's summary judgment for Eisai, granted in October 2006, rejecting the generic challenger's invalidity arguments and finding Eisai's patent non-obvious.

The Paul Hastings team was led by New York partners Joseph O'Malley and Bruce Wexler, and included associates David Conca, Gary Ji and Quinn Clancy.

About Eisai Co., Ltd.: Eisai Co., Ltd. is a research-based human health care (hhc) company that discovers, develops and markets products throughout the world. Eisai focuses its efforts in three therapeutic areas: neurology, gastrointestinal disorders and oncology/critical care. Through a global network of research facilities, manufacturing sites and marketing affiliates, Eisai actively participates in all aspects of the worldwide healthcare system.

About Paul Hastings' Litigation Department: The Paul Hastings Litigation Department provides premier litigation services to clients facing complex legal issues in the U.S., Europe, South America, the Middle East and Asia. With more than 300 lawyers in the Litigation Department, in addition to 200 litigators in the Employment Department, Paul Hastings is well positioned to handle all aspects of a client's litigation needs. Our sophisticated litigation practice covers every major practice including securities, intellectual property, class action and employment litigation, international arbitration, and white-collar crime. The Litigation Department has an impressive track record of winning large and difficult cases.

Paul, Hastings, Janofsky & Walker LLP, founded in 1951, is a leading international law firm with over 1,200 attorneys in 18 offices. The firm serves a diverse client base including many of the leading global financial institutions and Fortune 500 companies and offers deep capabilities in capital markets, finance and restructuring, intellectual property, international arbitration and dispute resolution, investment management, labor and employment, mergers and acquisitions, private equity, product liability, project finance, real estate, securities litigation and tax advisory services. For additional information, please visit our website at www.paulhastings.com.