Regeneron Pharmaceuticals Inc (Respondent) v Kymab Ltd (Appellant)  UKSC 27
Date of judgment: 24 June 2020
In a dispute challenging the validity of two patents held by Regeneron Pharmaceuticals (“Regeneron”), the Supreme Court held by a majority of four to one that Regeneron’s patents did not enable a skilled person to make transgenic mice other than in a relatively small area of the scope claimed, and consequently were insufficiently disclosed. The decision emphasises the quid pro quo of the patent system – that the scope of the monopoly must be commensurate with the technical contribution made by the inventor.
In 2001 Regeneron filed patents covering genetically modified mice. Regeneron’s innovation was a hybrid version of the gene that produces antibodies, combining a section of the mouse’s genetic material with a section of a gene from a human (the “variable region”). The resulting mice produce antibodies which are suitable for medical treatment in humans, but are sufficiently similar to mouse antibodies that they do not cause immunological reactions in the host animal.
The Court of Appeal found that Regeneron’s patents contained enough information to enable a skilled reader to insert some of the human material into a mouse’s genes; however, the patents did not explain how to create a hybrid structure incorporating the full human variable region genes into the mouse’s genome. That was not achieved until a later date. However, because the patents had disclosed “a principle of general applicability,” they fulfilled the requirement of sufficiency.
The Supreme Court disagreed. The emphasis of their reasoning was based the principle that a patent is a fair bargain struck between the inventor and the public; namely, that a patentee disclose the invention completely so as to enable the skilled person to work the invention in all aspects, in return for a time-limited monopoly over its use. The Supreme Court found that Regeneron’s patents did not enable a skilled person to make mice containing more than a very small section of the human variable region. This was important – antibodies (and mice) of a more valuable type could not be made using Regeneron’s patents.
The sufficiency requirement of Article 83 may still be satisfied where there are or may be a tiny or inconsequential number of embodiments which are not enabled. However, in the case of the Regeneron patents, the enablement shortfall was not considered to be de minimis.
The Supreme court supported the concept of “a principle of general application”. However, in the present case claim 1 failed for sufficiency because at the priority date the disclosure of the two patents, coupled with common general knowledge, did not enable transgenic mice to be “made” containing more than a very small part of the human variable region gene locus.
The judgment makes it clear that the sufficiency requirement is an indispensable requirement which should enable all the products within the scope of the claims and not allow an extension of the monopoly which exceeds the contribution to the art. Applicants need to be aware of the decision when drafting claims, and avoid speculative “overclaiming” beyond what they have actually invented.
Case ID:  UKSC 27
Dr Adrian Bradley (Partner)
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