High Quality Content by WIKIPEDIA articles! Kirin-Amgen, Inc. v Hoechst Marion Roussel Ltd. is a decision by the House of Lords of England and Wales. The judgment was issued on 21 October 2004 and relates to the scope to be accorded to patent claims, including the doctrine of equivalents. The case and subsequent judgment affirmed principles from a prior case, Catnic Components Ltd. v. Hill & Smith Ltd.