The UK Supreme Court\u2019s decision in Actavis v Eli Lilly [2017] UKSC 48<\/a> represents a sea change in the determination of patent scope in the UK.\u00a0 In order to align more fully with the Protocol on the Interpretation of Article 69 EPC (European Patent Convention), the Court considered that the extant approach to claim construction needed to change.\u00a0 Accordingly, the single-stage \u201cpurposive\u201d assessment that had been the mainstay of the English courts\u2019 methodology of determining patent scope for the previous 35 years was swept away.\u00a0 Distinctions have therefore now been drawn between \u201cconstruction\u201d and \u201cscope\u201d, and explicit recourse to a doctrine of equivalents \u2013 a doctrine much derided under the previous regime \u2013 has (finally) been embraced.\u00a0 This lecture will examine the effects of the decision and the broader notion of equivalency within patent law.\u00a0 In doing so, it aims to address the benefits and disadvantages of the Supreme Court\u2019s approach and to assess the likely challenges that such a shift in approach will bring.<\/p>\n