IP-Fälle und Artikel

UK Supreme Court changes law on scope of protection

On Wednesday 12 July 2017 the UK Supreme Court handed down judgment in Lilly v Actavis. In a decision that is likely to surprise many, the court appears to have fundamentally altered the law in the UK on scope of protection.

Prior to this decision, the approach to scope of protection in the UK was that set out in Amgen v Hoechst [2005] RPC 9 (another Supreme Court case), which essentially held that the question would be determined by deciding whether the alleged infringement fell within the meaning of the claim language when construed "purposively". The court in that case held that this approach was consistent with Article 69 of the European Patent Convention, and its Protocol (which expressly says that regard should be had to "equivalents"). The court in Amgen stated clearly that there was no doctrine of equivalents in the UK, and no accompanying doctrine of file wrapper estoppel.

New UK doctrine of equivalents

The decision of the Supreme Court today is a very substantial change from the "purposive construction" approach adopted up to now by the UK. Crucially, the court said that there can be a difference between the interpreted scope of a claim and the scope of protection afforded by it, apparently introducing a form of doctrine of equivalents into UK law. In summary, the Supreme Court stated that infringement should be approached by addressing two issues:

  1. Does the item in question infringe any of the claims as a matter of "normal" interpretation; and if not
  2. Although the item may be characterised as a variant, does it nonetheless infringe because it varies from the invention in a way which is immaterial?

If the answer to either is "yes", there is infringement.

As a guide to answering the second question, the so-called "Improver" (or "Protocol") questions, long used to assess variants under UK law before the Amgen case relegated them to secondary guidance only, have again become prominent. The court has reformulated these questions as follows, holding that they should be used to assess the second issue:

Notwithstanding that it is not within the literal meaning of the relevant claim(s) of the patent, does the variant achieve substantially the same result in substantially the same way as the invention, ie, the inventive concept revealed by the patent?

  1. Would it be obvious to the person skilled in the art, reading the patent at the priority date, but knowing that the variant achieves substantially the same result as the invention, that it does so substantially the same way as the invention?
  2. Would such a reader of the patent have concluded that the patentee nonetheless intended strict compliance with the literal meaning of the relevant claim(s) of the patent was an essential requirement of the invention?

File wrapper estoppel

In Amgen, the court held firmly that there was no file wrapper estoppel in the UK, mainly because it also said there was no doctrine of equivalents. Today's decision in Lilly v Actavis seems to open the door to a form of file wrapper estoppel. In his judgment today, Lord Neuberger held that UK courts should be sceptical but not absolutist in relation to reference to the prosecution file on the question of infringement. Without limiting the circumstances in which reference may be made, the court said that reference to the file would be appropriate where:

  • the point at issue is truly unclear but can be clarified by reference to the file; or
  • it would be contrary to the public interest for the contents of the file to be ignored.

In the case of the latter, the court gave as an example the situation where the patentee had made it clear to the EPO (or EPC national offices) that he was not seeking to contend that his patent, if granted, would cover the sort of variant which he later claimed infringed. This example opens the door to file wrapper estoppel, and disputes as to what constitutes "making clear" to the patent office in a given situation.


Today's decision opens the door to a doctrine of equivalents in the UK and substantially alters the approach to scope of protection previously adopted in the UK. Reference to the language of the claim, construed purposively, will no longer deal with the question of infringement. In addition, a limited form of file wrapper estoppel does now appear to be part of UK law when considering the question of infringement by a variant.

We would note that the court also dealt with infringement in France, Italy and Spain, reaching the same conclusion for similar reasons.

A more detailed analysis of this case and the parallel proceedings in Germany will be published soon.