The U.S. District Court for the Eastern District of Virginia invalidated Pfizer’s method-of-use patent on its Celebrex painkiller. The basic chemical patent on Clebrex will lapse May 30, 2014. Pfizer hoped the method-of-use patent would allow it to maintain market exclusivity on Celebrex through Dec. 2, 2015. Pfizer currently enjoys $3 billion in annual sales from the drug. Pfizer will no doubt appeal the adverse patent decision to the Federal Circuit Court of Appeals.