Aralez Pharmaceuticals Inc., two of its units and Pozen Inc. sued Teva Pharmaceuticals USA Inc., a unit of Teva Pharmaceutical Industries Ltd., for infringement of four patents covering Yosprala.

The suit, filed Jan. 23 in the U.S. District Court for the Eastern District of Texas, concerns an abbreviated new drug application filed by Teva with the U.S. FDA seeking approval to market generic versions of Yosprala prior to the expiration of the identified patents.

Three of the patents are listed in the approved drug products with therapeutic equivalence evaluations, known as the orange book, of the FDA. Pozen plans to list the fourth patent in the orange book.

Yosprala is a combination of aspirin and omeprazole, used to treat patients who need aspirin for secondary prevention of cardiovascular and cerebrovascular events and who are at risk of developing aspirin-associated gastric ulcers.