On 11 and 12 February the UK Supreme Court heard the appeal brought by Kymab against the judgment of the Court of Appeal which  found Regeneron’s European Patents (UK) No 1 360 287 and its divisional EP (UK) No 2 264 163 valid and infringed, reversing the invalidity finding of the first instance court (see our analysis of the first instance judgment here). The Supreme Court hearing can be viewed here.

Kymab appeals the Court of Appeal’s validity findings relating to sufficiency, arguing that the Court of Appeal wrongly interpreted and applied the law of insufficiency which requires the skilled person to be able, at the priority date, to perform the invention over the whole area claimed without undue burden or inventive skill. Kymab argues that, on the findings of the Court of Appeal, the skilled person could not, at the priority date, perform Regeneron’s invention which related to transgenic mice with reverse chimeric locus over the whole area of the claims (Claim 1 of EP’163 or Claims 5 and 6 of EP’287), without undue burden or inventive skill. Namely the skilled team could not create a transgenic mouse with a complete variable region of the human immunoglobulin locus which is covered by Claim 1 of EP’163.

Regeneron’s response is that the Patents are sufficient where the information disclosed in the specification enables the skilled team, as at the priority date, to produce transgenic mice within the scope of the claim, even though the information disclosed did not enable the skilled team, at that time, to make all transgenic mice with reverse chimeric loci which could fall within the scope of the claim. The reason why the information disclosed suffices is because the invention is a principle of general application, the skilled team would reasonably expect the invention to work across the scope of the claim, and the Patents only claim embodiments that use that technical contribution.

We await the Supreme Court’s judgment which may have potentially far-reaching implications on the law of sufficiency.

Monika Klajn
Monika Klajn
+44 20 7466 7604