Patent construction after Amgen: are patent claims construed more widely or narrowly than previously?

Legal context. This article considers the UK Courts' approachto patent construction since the House of Lords' decision inKirin-Amgen Inc v Hoechst Marion Roussel Limited, which washanded down in October 2004, and seeks to examine whether theUK Courts' construction of patents is wider or narrower thanpreviously. Key points. The available data appear to suggest that thereis little difference in outcome, whether the old Improver testis applied or the new Kirin-Amgen test; of more significanceremains the nature of the wording of the patent claims themselvesand the correct identification by the trial judge of the inventionunderlying the patent. Practical significance. By eschewing a literal approach andrefining the test used in order to ensure both compliance withthe EPC and consistency with courts in other European countries,the UK Courts continue to provide an attractive forum for resolutionof patent disputes.