Wednesday, 30th August, 2017

Big changes in how to interpret a patent’s scope of protection

A recent decision of the Supreme Court in the United Kingdom (UK), Actavis v Eli Lilly [2017] UKSC 48, has re-written the rules of claim construction. Specifically, how to interpret the scope of protection granted to a patent owner and, hence, whether a competitor’s activities infringe or not.

It has long been possible to argue a slightly broader scope than what is defined by all features of a patent claim. However, the new decision introduces a more comprehensive ‘doctrine of equivalents’. In other words, an essential feature in a claim could be substituted for an alternative, so long as that alternative achieves the same result in the same way as the original feature; i.e. it is ‘equivalent’ in the context of the inventive concept.

By issuing this decision, the Supreme Court judges have effectively further harmonised UK patent law with the law of other European countries where, in the past, different decisions have been reached for the same scope of patent claims. For example, in the Improver v Remington (1990) case regarding the Epilady™ epilation device, the UK court famously found non-infringement whereas courts in Germany, Italy and the Netherlands found infringement. The Supreme Court even went so far as to suggest that it may have decided the Improver case differently, had it been brought today.

The new guidance has sent shockwaves through the patent profession in the UK because it allows a broader interpretation of what amounts to an equivalent feature infringing a patent that may not have before. This is to the benefit of patent owners.

Also, somewhat controversial in the decision was the issue of whether comments/amendments made during the examination of a patent can be raised in later litigation. The Court has decided that file history can be taken into account when appropriate to interpret claim scope. This could potentially hinder a patent owner’s chance of success in proving infringement, although it did not have an adverse effect in the present case.

UK Supreme Court decisions do not bind New Zealand and Australian courts but it is likely that the new rules for determining whether an equivalent feature is an infringement or not will be highly persuasive in this part of the world. In any event, good practice is good practice wherever you are, so it is worth considering if the strength of a patent can be improved at the early stages of preparation. Additional consideration can, therefore, be given to:

  • providing disclosure of an invention at a general level, i.e. features described generically with alternatives provided where possible; 
  • discussion of the inventive concept, i.e. what the main features achieve rather than just specific form; and 
  • avoiding reference to ‘essential’ features in specifications and submissions during examination.

This decision of the UK Supreme Court will cause some uncertainty in the short term since existing infringement opinions may need to be revisited. However, in the long term, the new rules provide comparable certainty in the guidance they provide and enable greater harmonisation between patent systems.