The U.S. Court of Appeals for the Federal Circuit (CAFC) on Wednesday issued a precedential decision, affirming a district court ruling that Mylan Pharmaceuticals Inc. did not infringe two patents owned by Actelion Pharmaceuticals Ltd. covering a lyophilized epoprostenol formulation used to treat pulmonary arterial hypertension. The decision centered on how a single claim term, “a pH of 13 or higher,” should be measured, and whether Actelion could pursue infringement through the doctrine of equivalents.