AstraZeneca has filed a lawsuit in the United States District Court for the District of New Jersey against Teva Pharmaceuticals USA, Inc. and Teva Pharmaceuticals Industries, Ltd. for wilful infringement of AstraZeneca's substance patent protecting Seroquel.

The lawsuit is in response to an abbreviated new drug application filed by Teva with the US Food and Drug Administration regarding Teva's intent to market a generic version of AstraZeneca's Seroquel (quetiapine fumarate) in the US prior to the expiration of AstraZeneca's patent no. 4,879,288, which is listed in the FDA's orange book and which expires in 2011, subject to any extension, states a company release

AstraZeneca will continue to defend and enforce its intellectual property rights protecting Seroquel.