Split patent decison for Amgen and Shire

USA-headquartered Amgen, the world's largest biotechnology company, has won a partial victory in a patent dispute with fellow US firm Transkaryotic Therapies (now owned by the UK's Shire) and Aventis Pharmaceuticals, part of the French Sanofi-Aventis group, regarding the anemia drug erythropoietin.

The Court of Appeals for the Federal Circuit reviewed the 2004 District Court findings on the infringement and validity of two patents with claims to the production of EPO, which Amgen markets as Epogen, the infringement of one product patent under the doctrine of equivalents and the validity of one product patent.

The Appeals Court decided that the production patents were valid and infringed, thus effectively making sure that Shire's anemia drug Dynepo (epoetin delta) is kept off the US market. Aventis returned the rights to this product to Transkaryotic in 2004.