Regeneron v Kymab [2020] UKSC 27

24 June 2020

Michael Tappin QC, along with Iain Purvis QC, appeared on behalf of the Appellant in this appeal to the Supreme Court involving the patent issue of sufficiency. The Supreme Court allowed Kymab’s appeal by a majority of four to one, holding that Regeneron’s patents were invalid.

The patents concerned a new type of genetically modified mouse which combined a section of the mouse’s genetic material with a section of genetic material from a human. The Court of Appeal had upheld the patents over a range of mice even though Regeneron’s patents only contained enough information to enable the skilled person to make mice over a small part of the range, finding that Regeneron’s idea was a “principle of general application”. Kymab appealed to the Supreme Court.

The Supreme Court held that patentees must disclose enough information to enable the skilled person to make substantially all the types or embodiments of products within the scope of the claim, and may only rely upon a principle of general application if it enabled a significant, relevant, part of the claimed range to be made, as at the priority date. A range would be relevant if it was denominated by reference to a variable which significantly affected the value or utility of the product in achieving the purpose for which it was to be made.

The amount of human genetic material that could be combined to a mouse’s genetic material was understood to be a very important factor affecting the diversity of useful antibodies which the mouse would produce, so that the claimed range was a relevant one. Regeneron’s patents did not enable the skilled person to make mice across substantially the whole of that range and so were held to be invalid for insufficiency.

Lady Black gave a dissenting judgment, in substance agreeing with the Court of Appeal.

View judgment