Federal Circuit rejects challenge to GSK’s Avodart and Jalyn

The US Appeals Court for the Federal Circuit has affirmed a lower court decision that GlaxoSmithKline’s (GSK’s) patent covering Avodart and Jalyn is valid, rejecting claims put forward by a group of generic drug makers.

Banner Pharmacaps, Impax Laboratories, Roxane Laboratories, Mylan Pharmaceuticals and Watson Laboratories had intended to make generic versions of GSK’s dutasteride drugs Avodart and Jalyn, which are used to treat enlargement of the prostate gland.

The drugs are protected by US patent 5,565,467, which relates to “dutasteride and its pharmaceutically acceptable solvates”.

GSK sued the companies for patent infringement at the US District Court for the District of Delaware which, after a three-day bench trial, decided that the defendants had not proved the claims invalid.

While stipulating to patent infringement, the generic makers appealed against the decision of patent validity, arguing that the term “solvate” in the asserted patent claims had not been adequately described by the court.

The parties disagreed about whether “solvate” refers to just crystalline complexes of solute and solvent molecules, where dutasteride is the solute, or whether it also includes non-crystalline complexes, with GSK arguing for the broader definition and the generics for the narrower.

“The district court acknowledged defendants’ ‘considerable extrinsic evidence’ that, in the pharmaceutical field, ‘solvate’ is limited to crystalline complexes, no matter how created, but it concluded that the specification of this particular patent ‘direct[ly] contradict[s]’ any such usage,” Judge Taranto said in the February 24 decision.

The Federal Circuit decided that the claim term ‘solvate’ refers to a molecular complex defined by structure and by the process of creating it, not what it does, and affirmed the district court’s decision.

GSK told LSIPR that it is pleased with the court’s decision. Mylan did not respond to a request for comment.