Actavis v. Eli Lilly*: Back to the Future—The UK Supreme Court Changes the Test for Patent Infringement

The UK Supreme Court rarely hears patent cases, and will only hear cases that it considers to be fundamentally important. The court's July 12 judgment is most significant for changing the test for infringement in the United Kingdom, widening the scope for infringement by equivalence. But it also opens the door for relying on patent prosecution history in litigation; emphasizes the importance of judgments of other European courts, thus showing that the UK court is seeking a common European patent law; and demonstrates that the UK court is willing to adjudicate on infringement of patents of other European states.

A new test for the scope of protection

The court set out an approach to infringement in line with its interpretation of Article 69 of the European Patent Convention, and the Protocol on its interpretation.

First, it is necessary to establish whether a variant infringes the claim as a matter of "normal" interpretation. Second, the most important aspect of the judgment is the new test1 for the scope of protection in relation to a variant on what is literally required by the claim, summarized as follows:

"i) Notwithstanding that it is not within the literal [i.e. contextual] 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?

ii) 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?

iii) 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?"

Under the new test, variants may now infringe even if the skilled addressee did not know in advance that they would work, and even if it was not obvious that they would work. The new test assumes that the skilled addressee knows that the variation works (to the extent that it actually does work).

Prosecution history may be admissible in some circumstances

In relation to patent prosecution history, the UK Supreme Court has diluted a previous rule that excluded its use in litigation. References to the file are still discouraged but "would only be appropriate where (i) the point at issue is truly unclear...