Of Mice And Patents — Kymab Beats Regeneron For Insufficiency

This article was first published in Lexis®PSL IP & IT analysis on 11 February 2016.

What does this case tell us about insufficiency? Dr Beatriz San Martin, partner at Fieldfisher, draws out key points and lessons from Regeneron Pharmaceuticals Inc v Kymab.

Regeneron Pharmaceuticals Inc v Kymab Ltd and another [2016] EWHC 87 (Pat) [2016] EWHC 87 (Pat)

The Patents Court made rulings in a claim concerning transgenic mice that could be used as platforms for therapeutic antibody discovery. In dismissing the claim of Regeneron Pharmaceuticals, the court held that the defendants' counterclaim for insufficiency of the patent succeeded.

What is the commercial and legal background to this judgment?

The claimant, Regeneron, brought a claim for infringement of two of its European patents (UK) — EP(UK)1,360,287 (the 287 Patent) and EP(UK)2,264,163 (the 163 Patent) — with priority dates of 16 February 2001 (the priority date), which relate to transgenic mice that can be used as platforms for therapeutic antibody discovery. Kymab, the defendant, offered various strains of transgenic mice that were alleged, either per se or through the process by which they are produced, to infringe claims 5 and 6 of the 287 Patent and claim 1 of the 163 Patent (the Claims).

Kymab denied infringement and, as is usual in these cases, counter-claimed for revocation of the patents on the basis of insufficiency, 'cross anticipation', lack of novelty, obviousness and added matter. There was a second defendant, Novo Nordisk, although the claim against it was abandoned shortly before trial. For the purposes of this article, the reference to Kymab is to both defendants.

Claim 1 of the 287 Patent was also considered in detail as being relevant to the construction of claims 5 and 6 and issues of validity.

What were the legal aspects of the insufficiency attack?

Henry Carr J provided a summary of the law on both 'classical insufficiency' and 'excessive claim breadth' insufficiency before concluding that claim 1 of the 287 Patent was invalid for insufficiency on the basis that the whole of the subject matter of claim 1 was not capable of being performed at the priority date without undue burden and without invention. According to Henry Carr J: 'the task contemplated was unprecedented and could not have been achieved, if at all, without a great deal of creative thinking at the priority date.'

As Henry Carr J had concluded that claims 5 and 6 of the 287 Patent were of considerably wider...