Regeneron Supreme Court ruling highlights risk in certain patent filing strategies

The court was ruling (34-page / 128KB PDF) in a case involving biotech rivals Regeneron and Kymab. The companies are involved in a long-running global dispute concerning patents owned by Regeneron.

The case centred on two patents Regeneron owns concerning the production of human antibodies using transgenic mice. The patents describe a technique for making such antibodies for treating human disease. Kymab has developed its own genetically modified mice based on a similar genetic structure to Regeneron's. Regeneron sued Kymab for patent infringement, but Kymab counterclaimed that Regeneron's patents are invalid.

Kymab's arguments have focused in particular on the concept of sufficiency in UK patent law, which requires patent owners to disclose enough information about the claimed invention to allow 'a person skilled in the art' to perform the invention claimed by the patents themselves.

The High Court initially ruled in Kymab's favour in 2016, but the Court of Appeal overturned that decision in 2018. The Court of Appeal ruled that Regeneron had "clearly enough and completely enough" disclosed the patent claims, stating that Regeneron had met its disclosure obligations even though it had not specified precisely how a skilled person might insert the full range of human variable genes into mice. The Court of Appeal reached that view after determining that Regeneron's invention was a "principle of general application".

However, Kymab took the case to the Supreme Court which has now upheld its appeal.

"Today’s judgment has been highly anticipated by the life sciences sector and will impact on future patent filing strategies," said Nicole Jadeja of Pinsent Masons, the law firm behind Out-Law. "The clear message from the judgment is that applicants take a risk if they file patent applications too early based on aspiration and not technical contribution. The risk-reward dynamic can be challenging for patentees and, in particular, biotech companies who often grapple with when to file. If they file too early they may not be able to protect the full scope of their contribution, and filing too late can mean that they are unable to secure investment."

Anna Harley, also of Pinsent Masons, said the dispute before the Supreme Court was particularly interesting given the ground-breaking innovation that Regeneron developed.

Harley said: "Regeneron's ground-breaking technology impressed the courts. However, the Supreme Court's decision makes it clear that if a claimed monopoly defines a whole range of products, all of those products must be appropriately enabled by the patent specification."

"While the patents in question claimed new and inventive techniques, not all products claimed were enabled at the priority date of the patent.  This ultimately led to the Supreme Court finding in Kymab's favour, invalidating the patent," she said.

Sarah Taylor of Pinsent Masons said the case is the latest ruling in recent times to explore the information that prospective patent owners must disclose when filing for patent protection.

Taylor said: "This decision is a reminder that life sciences companies risk revocation of their patents if they fail to disclose sufficient information to enable skilled persons to perform the inventions claimed in those patents. This forms part of the so-called 'patent bargain' that sees inventors granted monopoly rights over products or processes in return."

"Patent filing strategies will vary between businesses and will be dependent on many things, including the nature of the products or commercialisation of the techniques in question. The competing tensions facing life sciences businesses, particularly smaller biotech companies, is the competitive and financial pressures that drive the need for early filing of patent applications set against the risk of making claims about those patents that cannot be wholly substantiated and which might later be challenged. Businesses can enjoy significant commercial benefit from early filing of patents but it this ruling shows the risks involved in making overly broad claims which cannot be fully supported," she said.