Allergan has filed a petition for rehearing with the U.S. Court of Appeals for the Federal Circuit, challenging the court’s recent decision to overturn a $39 million jury verdict against Sandoz Inc. in a patent infringement case concerning the eyelash growth drug Latisse®. Allergan contends that the appellate court’s ruling misinterpreted the trial record and was based on an “indisputably false” premise.
The dispute centers on U.S. Patent No. 9,579,270, which covers methods of treating hair loss using compositions containing prostaglandin F (PGF) analogs. Allergan, in partnership with Duke University, alleged that Sandoz’s generic version of Latisse® infringed claim 30 of this patent. In 2018, a jury found in favor of Allergan, awarding $39 million in damages. However, on November 18, 2025, the Federal Circuit reversed this verdict, declaring claim 30 invalid for lack of adequate written description. The court concluded that the patent’s specification did not sufficiently demonstrate that the inventors possessed the full scope of the claimed subgenus of PGF analogs, including the specific compound bimatoprost used in Latisse®.
In its petition for rehearing, Allergan argues that the Federal Circuit’s decision misinterpreted the evidence presented at trial. The company asserts that the court’s conclusion was based on an incorrect understanding of the patent’s disclosure and the testimony of expert witnesses. Allergan maintains that the patent’s specification provides sufficient detail to demonstrate possession of the claimed invention and that the jury’s original verdict should be reinstated.
The Federal Circuit’s ruling has significant implications for the pharmaceutical industry, particularly concerning the standards for written description in patent applications. The decision reinforces the necessity for patent specifications to clearly demonstrate that the inventors were in possession of the full scope of the claimed invention at the time of filing. This case highlights the challenges innovators face in drafting patent applications that meet stringent legal requirements while adequately protecting their inventions.
As the legal proceedings continue, the outcome of Allergan’s petition for rehearing will be closely watched by legal professionals and industry stakeholders. The case underscores the importance of precise and comprehensive patent drafting, especially in the competitive pharmaceutical sector, where the validity of a patent can have substantial financial and market implications.