Cephalon has filed a patent lawsuit against Teva Pharmaceuticals, claiming infringement after Teva launched an Abbreviated New Drug Application (Anda) for a generic of the stimulant Nuvigil.

Cephalon holds patents for the drug, which is used to improve wakefulness in people who suffer from sleeping disorders and jet lag. The patents extend to 15 June 2010. In addition, Cephalon’s patent includes six-month pediatric extensions, which expire on 6 April 2015, 29 May 2024 and 18 June 2024.

Teva alleges that these Nuvigil patents are invalid and unenforceable and that in any case they will not be infringed by Teva’s manufacture, use or sale of the generic.

Cephalon, however, is insisting that the patents, approved by the US Patent & Trademark Office, are valid, enforceable and are indeed being infringed by the proposed Teva ANDA product.

Cephalon executive vice-president and general counsel Jerry Pappert said that the firm’s patent position for this product is strong and it intends to vigorously defend its intellectual property.

The filing of the lawsuit stays any Food and Drug Administration approval of the Teva ANDA until a district court judgment is reached.