On 12 July 2017, the Supreme Court handed down its judgment in Actavis UK Limited v Eli Lilly which reformulates the approach to be taken when determining the scope of a patent claim and sets out the extent to which the courts can step outside the wording of a claim to find infringement in relation to "equivalent" means.

In this alert, we summarise some of the key elements of the decision and the potential impact it could have going forward.

Key points

  • The Supreme Court has set out revised guidance which will result in slightly less emphasis being placed on the meaning of the words of a patent claim and greater emphasis on whether that equivalent or variant "should" fall within the scope of protection as a matter of fair protection for the patentee
  • There may be greater risk of infringement for technologies that have been specifically "designed around" the scope of existing patents by using equivalent means or variants to avoid infringement
  • The decision resurrected and reformulated the well-known Improver questions and also indicates an intentional shift to greater consistency in the approach to patent construction as between the UK and certain other European countries.

Initial impact

The guidance in Actavis is now to be applied when determining whether a patent has been infringed where a variant does not fall within the literal scope of the claims. The reformulated questions ask: (i) whether the variant achieves substantially the same result in substantially the same way as the invention; (ii) whether this would be obvious to a person skilled in the art (knowing that the variant achieves substantially the same result in substantially the same way); and (iii) whether that skilled person would conclude that the patentee would have intended strict compliance with the literal meaning of the claims or not. The reformulated questions represent a substantial departure from the first and second limbs of the previous Improver questions that were used by the courts as guidelines to assess equivalents. This represents a shift by the courts from the previous approach which attributed too much weight on the words of a claim (as a matter of traditional interpretation) to what now more closely embodies a "problem/solution" approach to claim construction.

The proper approach to infringement claims

The Court recognised the importance of maintaining a balance between "fair protection" for a patent proprietor on the one hand, and "a reasonable degree of legal certainty" for third parties on the other, as enshrined in the Protocol to the Interpretation of Art 69 EPC. A number of UK cases had previously provided specific guidance on the steps the courts must go through when considering whether this balance had been achieved. The Catnic and Improver questions famously outlined principles that the courts should follow when determining whether an "equivalent" was likely to infringe. These questions were subsequently approved and consolidated in another high profile case, Kirin-Amgen, which remained one of the main authorities on patent claim construction until now.

In the present case, the Supreme Court have stated that the previous approach put too great an emphasis on the traditional exercise of judicial interpretation and that actually, the problem of infringement is best approached by looking at two issues (of which the judicial exercise of interpretation was only one):

(i) does the variant infringe any of the claims as a matter of normal interpretation, and if not

(ii) does the variant nonetheless infringe because it varies from the invention in a way or ways that is or are immaterial?

If the answer to either issue is "yes", then there will be infringement. The Supreme Court went on to reformulate these issues into new judicial questions (set out under "Initial impact" above and paragraph [66] of the judgment) which now replace the previous case law on the issue. Importantly, the Court went on to emphasise that the reformulated questions were not "strict rules" and that the EPC remains the underlying rationale and authority for their application.

The relevance of prosecution history

The Supreme Court has also clarified the existing position in relation to the use of the prosecution file as an aid to interpretation. It emphasised that references to the prosecution file to determine the scope of a patent must be limited and would only be appropriate if: (i) the point at issue is truly unclear if one confines itself to the specification and claims of the patent (and the contents of the file unambiguously resolve the point); or (ii) it would be contrary to the public interest for the contents of the file to be ignored.

The full decision can be found here: Actavis UK Limited and others (Appellants) v Eli Lilly and Company [2017] UKSC 48