Lord Neuberger’s reformulation of the so-called “Protocol questions” in the Activis v Eli Lilly decision in the UK Supreme Court seems likely to broaden the scope of patent protection in the UK by increasing the likelihood that an equivalent feature which does not literally infringe the wording of a patent claim but which otherwise achieves substantially the same result as a feature of a patent claim will be found to fall within the scope of the claim and thus comprise an infringement of the patent.

In assessing patent infringement it is first necessary to determine if the alleged infringement is covered by the literal wording of a patent claim. If it is not, it is then necessary to determine if the variant is an equivalent which nevertheless falls within the scope of the claim.

Before this new decision, this determination was carried out by considering the following questions, originating from Mr Justice Hoffman in the Improver case, where a variant will not infringe if any of the following are true:

1. The variant has a material effect on the way the invention works; 2. The fact that the variant has no material effect on the way the invention works would not have been obvious to an expert in the field at the date of publication of the patent; 3. That an expert in the field would have taken from the language used in the patent that strict compliance with the primary meaning was an essential requirement of the invention.

These questions have now been reformulated by Lord Neuberger to the following:

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, i.e. 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?

The full impact of this reformulation of the so-called “Protocol questions” will take time and further court decisions to be fully appreciated. However, imparting the skilled person with the knowledge that the variant achieves the same result as the invention seems to make it easier to conclude that it is obvious that it does so in substantially the same way and therefore that the variant falls within the scope of the patent claim. This knowledge is imparted at the date of infringement and therefore need not have been known at the date the patent was published (or drafted). Therefore it appears that the scope of a patent can be adapted to take account of recent advances.

Of crucial importance to patent attorneys is that the decision seems to have also increased the relevance of the prosecution history of the patent when determining the scope of a patent.

Previous decisions have taught that the prosecution history (i.e. correspondence with the Examiner before grant of the patent) should not be considered when determining the scope of a patent claim. However, in this Activis v Eli Lilly decision the UK Supreme Court concluded that reference to the prosecution history of the patent can be appropriate where (a) the point at issue is truly unclear if one confines oneself to the specification and claims of the patent, and the contents of the file unambiguously resolve the point, or (b) it would be contrary to the public interest for the contents of the file to be ignored. By virtue of this decision, every comment made to an Examiner during prosecution of a patent application may have a future impact upon the determination of the scope of the resulting patent by the court.