Decision of the United Kingdom Supreme Court on Non-Literal Infringement

Author: Anna L. Hatt
Case Reports

The United Kingdom Supreme Court has issued a judgment this week in Eli Lilly and Company v Actavis UK Limited, establishing new law on the scope of claims for infringement purposes.  Judgments of the Supreme Court are rare and have binding precedent on other United Kingdom courts.  This is the first time that claim construction has been considered since the Supreme Court was established in 2009.

The judgment is a departure from UK case law on claim interpretation in recent years and has met with some surprise from patent lawyers and patent attorneys.

Before this decision, the scope of a claim for infringement purposes has been based on what the skilled person would have understood the author of the claim wording to mean, following the Kirin-Amgen Inc. v Hoechst Marion Roussel Limited decision of the House of Lords (then the highest UK court) in 2004.

The Supreme Court has now indicated in Lilly v Actavis that an additional step should be added after this assessment to check for possible infringement by variants of the claimed invention.  The court’s reasoning was that proper effect needed to be given to the provisions of the European Patent Convention on infringement by equivalents, with a harmonised approach being taken by EPC member states.

The additional step is based on an updated version of the so-called Improver questions which were formulated in 1990 to assess infringement by variants.  The test has three sub-steps as follows:

  1. 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?
  2. 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 in substantially the same way as the invention?
  3. Would such a reader of the patent have concluded that the patentee nonetheless intended that strict compliance with the literal meaning of the relevant claim(s) of the patent was an essential requirement of the invention?

In order to establish infringement in a case where there is no literal infringement, a patentee would have to establish that the answer to the first two questions was “yes” and that the answer to the third question was “no”.

In the case in question, the patent claim required the chemotherapeutic drug pemetrexed in the form of its disodium salt.  The question before the court was whether the claim was infringed by use of pemetrexed in the form of its dipotassium salt and other non-sodium salt forms.  The first instance court and Court of Appeal had held that the claim was not infringed.  Surprisingly, the Supreme Court held that the claim was infringed based on the reformulated Improver questions.

This decision will have an impact on patent infringement litigation in the United Kingdom, and may well be welcome to proprietors asserting patent infringement.

However, the wider implications of the decision are not yet clear and may cause difficulties.  Validity was not at issue in the Lilly v Actavis case, and the Supreme Court did not comment on how claims should be interpreted for validity purposes.  In addition, the newly emphasised possibility of non-literal infringement makes the outcome of infringement cases less certain, which may lead to higher levels of litigation, at least in the short term.

Our discussion of further aspects of this Supreme Court decision is found here.

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