AstraZeneca settled a patent infringement lawsuit with Watson Laboratories, Actavis and EGIS Pharmaceuticals over the active ingredient in its cholesterol drug, Crestor.

Under the agreement, Watson and EGIS agreed that the patent for Crestor was valid, enforceable and would be infringed by Watson’s rosuvastatin zinc product and its rosuvastatin calcium product, according to London-based AstraZeneca.

AstraZeneca brought suit against Watson and EGIS in the U.S. District Court for the District of Delaware, alleging that Watson’s rosuvastatin zinc New Drug Application infringed AstraZeneca’s substance patent covering Crestor. Watson and EGIS filed counterclaims seeking declaratory judgment of noninfringement and invalidity of the substance patent.

The substance patent expires on Jan. 8, 2016, and a pediatric exclusivity period expires July 8, 2016. Under the settlement agreement, Watson will begin selling its generic version of Crestor and its rosuvastatin zinc product on May 2, 2016, at a fee to AstraZeneca until the end of pediatric exclusivity. The entry date could be earlier and the fees eliminated in certain circumstances.

All claims and counterclaims will be dismissed in a consent judgment entered by the U.S. District Court for the District of Delaware.