Kymab emerges victorious in Regeneron patent battle

Cambridge, UK-based biopharma Kymab has emerged victorious from a long-standing battle with US biotech Regeneron over the validity of the latter’s patents regarding genetically modified mice.

The UK’s Supreme Court ruled that the claims of the two patents owned by Regeneron that were asserted against Kymab are invalid, upholding a 2016 High Court decision and revoking a subsequent Appeal Court’s determination that they were valid.
In 2001, Regeneron filed patents for a new type of genetically modified mouse that included a hybrid version of a gene that produces antibodies, by combining a section of the mouse’s genetic material with a section of genetic material from a human.
The resulting mouse can be used to produce antibodies suitable for medical treatment in humans, but also similar enough to mouse antibodies that they don’t cause an immunological reaction in the host mouse.

In 2013, the firm sued Kymab for infringement of its patents, as Kymab was producing its own genetically modified mice, branded Kymice, with a similar genetic structure to Regeneron’s. However, Kymab argued that Regeneron’s patents were invalid because they failed to adhere to a patent law rule called ‘sufficiency’, ie the need for documents filed with the patent to be detailed enough to enable recreation of the invention.

The Court of Appeal found that Regeneron’s patents contained enough information to enable an expert reader to insert some of the human material into a mouse’s genes, but not how to create a hybrid structure incorporating the full human variable region genes into the mouse’s genome. Still, it upheld the patents, ruling that there was no need for them to explain how to make the full range of mice because Regeneron’s idea was a ‘principle of general application’.

Kymab then appealed to the Supreme Court, which countered the Appeal Court’s decision by ruling that Regeneron’s patents are indeed invalid, and essentially clearing Kymab of any infringement in producing its Kymice.

“This case was a David and Goliath battle between Kymab, a British biotech pioneer, and Regeneron, one of the world’s largest biotech companies, and ultimately the Supreme Court came down on the side of Kymab – it’s a terrific result for Kymab and we’re delighted to have supported them in this hotly contested patent dispute,” said Dr Penny Gilbert, partner at IP law firm Powell Gilbert.

“This case raised fundamentally important questions of patent law relevant to a wide variety of innovative life science companies in the UK. The Supreme Court has confirmed that patents should not be available for inventions that are not adequately enabled.

“The judgement has profound implications, not only for the biotech and wider life sciences sector, but also for all manner of products being developed that depend on patent protection.”

“We are grateful that the Court has recognised the shortcomings of the Regeneron patents and reinforced the established law that requires that an invention is adequately enabled across its scope”, said Simon Sturge, Kymab’s chief executive.

“Kymab’s IntelliSelect platforms continue to generate best in class, fully human monoclonal antibodies, underpinned by our extensive IP estate.”