Cephalon files patent infringement lawsuit against Teva.

The article reports that Cephalon Inc. has filed a lawsuit in the U.S. District Court in Delaware against Teva Pharmaceuticals USA Inc. for infringement of several U.S. patent numbers for its product, Nuvigil tablets. Cephalon has a three-year period of marketing exclusivity for Nuvigil that extends until June 15, 2010. Teva did not challenge the U.S. patent number 4,927,855 which provides additional protection until October 22, 2010.