The case has moved through the U.S. District Court for the Northern District of West Virginia and the Federal Circuit twice. In 2023, the Federal Circuit vacated an earlier infringement judgment and remanded for the district court to consider extrinsic evidence on how a person of ordinary skill would interpret the pH limitation. On remand, the district court again ruled for Mylan. The Federal Circuit's May 13, 2026 precedential decision now affirms that outcome.
The ruling matters because it removes a significant regulatory obstacle for Mylan's ANDA pathway to generic approval. Beyond this case, the decision establishes precedent on how courts construe measurement conditions in patent claims and applies both prosecution history estoppel and the disclosure-dedication rule to defeat doctrine-of-equivalents arguments. Attorneys handling pharmaceutical patent disputes should note the court's approach to technical claim construction and the weight given to extrinsic evidence in interpreting functional limitations.