Posted: April 26th, 2018
Regeneron Pharmaceuticals, Inc v Kymab Limited and Novo Nordisk A/S (UK Court of Appeal, 28 March 2018,  EWCA Civ 671)
The UK Court of Appeal has handed down judgment in the case of Regeneron Pharmaceuticals Inc. v Kymab Ltd and Novo Nordisk A/S ( EWCA Civ 671), which will now stand as an important authority on the law of insufficiency. At first instance Mr Justice Henry Carr had held that two Regeneron patents were invalid on the ground of insufficiency. He also held that, if valid, Kymab’s transgenic mice would have infringed the patents. Regeneron appealed the finding of insufficiency and Kymab appealed the finding of infringement.
Both patents in suit arise from an invention with two aspects: (1) the “in situ replacement” of the variable domain parts of the mouse antibody loci with human antibody encoding sequences creating a “reverse chimeric locus”; and (2) a molecular biological method for targeted replacement of endogenous genes (such as the mouse antibody loci) with foreign DNA.
The Court of Appeal first dealt with an issue of construction. Both patents use the phrase “in situ replacement” in claim 1. Kymab contended, as its main non-infringement argument, that the phrase required the endogenous mouse DNA to be deleted. The Court of Appeal rejected Kymab’s construction, agreeing with the trial judge’s view that what was required was “positional replacement” of the endogenous mouse DNA and that this did not require deletion of that DNA. This construction distinguished the claimed approach from methods that allowed random integration of foreign DNA. Kymab’s appeal on infringement was accordingly dismissed.
The Court of Appeal proceeded to review the law regarding insufficiency at length, referring to both EPO Board of Appeal decisions and to UK domestic jurisprudence.
The trial judge had held that claim 1 of one of the patents in suit was insufficient as it did not enable the genetic modification across the full breadth of the claim, in particular with all sizes of genetic sequence modification, without undue burden and without invention. The other claims at issue, being of wider scope, were also held to be insufficient.
In contrast, the Court of Appeal held that technical contribution of the patents was the use of a “reverse chimeric locus”. This was a principle of general application and was a feature of all claimed embodiments. A specific problem for Regeneron was that Example 3 of the patent, as described, could not have been performed by the skilled person. However, the Court held that the skilled person could have adapted Example 3 without undue effort and thereby produced transgenic mice falling within the patent claim.
The Court of Appeal noted, inter alia, that if the claim was limited to only those embodiments enabled at the priority date then protection would rapidly become ineffectual; that the skilled person was not bound to carry out the invention as described (i.e. Example 3); and further inventive improvements that work the invention still benefited from the reverse chimeric locus concept. As such the Court held that the patents claims were sufficient across their scope and allowed Regeneron’s appeal. Thus, the patents were valid and infringed.
A copy of the judgment can be read here.
Headnote: Ian Turner and Graham Burnett-Hall, Marks & Clerk Solicitors LLP