Have you enabled your disclosure for the UK (or Europe)?

The UK Supreme Court has handed down its judgement in Regeneron Pharmaceuticals Inc v Kymab Ltd ([2020] UKSC 27) holding that Regeneron’s patents EP(UK) 1 360 287 and EP (UK) 2 264 163 were invalid as they did not sufficiently disclose the invention over the entire scope of the claims.

Under European law, a patent must disclose the invention in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art. The Boards of Appeal of the European Patent Office have held that this means substantially any embodiment of the invention as defined in the broadest claim must be capable of being realised on the basis of the disclosure (T226/85).

Regeneron’s patents cover transgenic mice that were significantly more useful at producing antibodies than those of the prior art. The transgenic mouse claimed by Regeneron contains what was referred to as a “reverse chimeric locus” in their genetic composition, whereby specific regions of mouse DNA are replaced with specific regions of human DNA. More specifically the transgenic mouse comprises “an in situ replacement of mouse VDJ regions with human VDJ regions at a murine chromosomal immunoglobulin heavy chain locus and an in situ replacement of mouse VJ regions with human VJ regions at a murine chromosomal immunoglobulin light chain locus”.

The claims cover a range of transgenic mice – arising from the meaning of the phrase “with human VDJ regions” in the heavy chain locus, and the phrase “with human VJ regions”. Regeneron argued that “the existence of this range was irrelevant because the unique advantage conferred by the use of a reverse chimeric locus, namely a cure for the immunological sickness of the recipient mouse, worked across the whole range, regardless of the amount of the human variable region DNA inserted into the murine genome.”

Kymab argued that the range of human DNA which could be inserted into the mouse genome was of critical importance because of its effect upon the ability of a particular type of mouse to produce a wide variety of B cells, and hence it’s potential to deliver a broad stream of useful antibodies.

In first instance proceedings, the patent disclosing the inventive concept was found insufficient. In its assessment of whether the patent sufficiently disclosed the invention, the Court of Appeal held that the sufficiency requirement was satisfied because the invention for which protection was claimed amounted to a ground breaking general principle and that all mice covered by the claims would display the particular benefits which the invention was designed to achieve.

However, in a four to one majority, the Supreme Court reversed the lower Court’s decision. In the minority, Lady Black considered that the range claimed coincides with the technical contribution of the patents which was to solve the problem of immunological sickness in mice.

While it may seem harsh to confine a patentee with a ground-breaking invention to protection only over a range of products, which “will give the patentee scant and short-lived reward for their efforts and ingenuity, viewed in particular with the benefit of hindsight” the Court held that “what matters is 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.”

So how do you enable your disclosure for the UK (or Europe)?

Under European law, there is no requirement for a patent to include a working example. However, the disclosure must provide sufficient information to the person skilled in the art to work the claimed subject matter without undue burden and without needing inventive skill.

Thus, where possible, including several working examples covering different embodiments covered by the broadest claim is advisable. If a limited number of working examples are available, alternative embodiments or variations extending over the entire scope of the claims should be fully and comprehensively disclosed in the description.

In our experience, in the chemical and life sciences, excessive claim scope is frequently a target in invalidity attacks. This is particularly relevant in the chemical arts when Markush formulae are used to claim a range of compounds. Oftentimes such attacks focus on the disclosure not being sufficient to enable all embodiments covered by the claims to be obtained, but usually the attacks amount to an allegation that a technical effect is not being achieved over the breadth of the claim – which is a matter of inventive step, not sufficiency of disclosure.

In either case, the attack stems from excessive claim scope. To defend such attacks the use of comparative examples to demonstrate the significance of endpoints of a range can prove vital in justifying scope for sufficiency of disclosure and are separately useful for substantiating inventive step.

Accordingly, when drafting patent applications which will be prosecuted in Europe, it is important to consider whether the disclosure is enabling for the entire breadth of the claims, and to build in multiple fall-back positions, which will facilitate amendment during prosecution or post-grant without extending the subject matter of the application or patent.

If you would like more information on the any of the topics discussed above please contact Con O’Connor or Donal Kelly.