Kirin-Amgen, Inc. and Others v. Hoechst Marion Roussel Limited and Others

Kirin-Amgen, Inc. (Amgen) (plaintiff) held a patent on a recombinant-DNA process for producing erythropoietin (EPO), and sued Hoechst Marion Roussel Limited, Transkaryotic Therapies Inc., and others (collectively TKT) (defendants) for infringement based on TKT's development of a similar EPO-production process. The trial judge construed the claim terms literally and, applying the Protocol questions under Article 69 of the European Patent Convention, found TKT's process did not infringe; the Court of Appeal affirmed, and Amgen appealed further.