Last month the UK Supreme Court issued a decision finding Regeneron’s patents for transgenic mice invalid for insufficiency (Regeneron Pharmaceuticals Inc v Kymab Ltd. [2020] UKSC 27), reversing the earlier decision of the Court of Appeal which had upheld the validity of the patents.

The case sets a precedent regarding sufficiency, which is the legal requirement for a patent claim to disclose an invention in a manner which is clear enough and complete enough for the invention to be performed by a person skilled in the art.

The decision is particularly important for those in the biotechnology sector as it may impact the validity of their existing patents and change their approach to future patent filings.

Background of the case

The appeal challenged the validity of two patents (European Patent (UK) 1360287 and European Patent (UK) 2264163) which sought to confer a monopoly over the creation of a range of types of transgenic mouse.

Previously, Regeneron brought proceedings against Kymab for the infringement of the VelocImmune patents. In response, Kymab counterclaimed that the patents were invalid for insufficiency. In the High Court, it was found that the claims were insufficient, since the one example in the patent of making the claimed mouse would not have worked because such a method was not possible at the priority date.

Kymab subsequently appealed to the Court of Appeal, where the Court disagreed with the High Court and found the patents to be sufficiently disclosed. As summarised in the Supreme Court’s decision, the Court of Appeal concluded that “the patent bargain requires that the reward given to the patentee should be commensurate with the contribution which the invention makes to the art. An invention which consists of a new generally applicable principle may contribute to the art by its use, not only in products which can currently be made, but equally in products which will only be capable of being made in the future, after further inventive research and development. To limit the patentee strictly to a monopoly over the products which can immediately be made would be to deprive the patentee of any reward for the public benefit which will be derived from the use of that same invention in future types of product. In a fast-moving field, where new products quickly outperform their predecessors so as to render them obsolete, the reward of a monopoly limited to those immediately capable of being made would be short-lived and illusory. Accordingly, the invention should be regarded as sufficiently enabled across the range if it can be seen that it will in due course benefit all products in the range, provided that, as at the priority date, the teaching in the patent enables at least one type to be made immediately.”

UK Supreme Court Decision

In a majority decision, the UK Supreme Court found that the Court of Appeal did not correctly apply the law as it stands. The Supreme Court noted that in the case of a product claim, the contribution to the art is the product which is enabled to be made by the disclosure, not the invention itself.

Importantly, the Supreme Court stated that “the sufficiency requirement, namely that the disclosure in the patent should enable substantially all products within the scope of a product claim to be made by the skilled person as at the priority date, is part of the bedrock of the law, worked out over time both in the UK and by the EPO, which is essential to prevent patentees obtaining a monopoly which exceeds their contribution to the art. To water down that requirement would tilt the careful balance thereby established in favour of patentees and against the public in a way which is not warranted by the EPC”.

In closing, the Court found that the claims lacked sufficiency, stating that “it is settled law, in relation to a product claim, that sufficiency requires substantially the whole of the range of products within the scope of the claim to be enabled to be made by means of the disclosure in the patent, and this both reflects and applies the principle that the contribution to the art is to be measured by the products which can thereby be made as at the priority date, not by the contribution which the invention may make to the value and utility of products, the ability to make which, if at all, lies in the future”.

However, Lady Black did offer a dissenting view on the decision, stating that she would have dismissed the appeal, since she agreed with the Court of Appeal that the invention related to a broad general principle and that every mouse encompassed in the claim will benefit from the technical contribution the disclosure of the patent has made to the art.

Implications of the decision

The Supreme Court confirmed in the decision that a claim which seeks to protect products which cannot be made by the skilled person using the disclosure in the patent will be considered to exceed the contribution to the art and thus be deemed insufficient.

This means that broad patent claims are likely to be vulnerable to attack. Consequently, care should be taken when pursuing a broad claim scope and should only be pursued in cases where it is reasonably certain that all products falling within the scope of the claims can be made from the disclosure in the patent.

This raises an important issue of when to file an application. Often, in the case of rapidly developing fields, applicants will look to file an application as soon as possible. As such, it is often the case that there is insufficient time to ensure that all products falling within the scope of the claim can be made. However, given the points raised in this judgment, it may be worthwhile giving greater consideration to whether all products falling within the claims can be made by the disclosure in the specification before filing the application to avoid falling foul to sufficiency issues during prosecution or in a third party attack.

If you have any questions on this judgement, please contact us to speak to one of our patent attorneys.