Sufficiency of a Range: UK Supreme Court

by Dennis Crouch

Regeneron Pharmaceuticals Inc. v Kymab Ltd., [2020] UKSC 27.

This important patent decision comes from the UK Supreme with a holding that Regeneron’s patents are invalid for insufficiency of the disclosure.  The insufficiency doctrine in the UK is parallel to US enablement law.

In the U.S., the courts have limited the enablement doctrine – especially considering McRO, Inc. v. Bandai Namco Games Am. Inc., 959 F.3d 1091 (Fed. Cir. 2020) (claims are valid absent identification of “concrete” and “particular” embodiment covered by the claim but not enabled).  Of course, the US now has a powerful eligibility doctrine that overlaps as well.

The Regeneron patents cover transgenic mice that produce human immunoglobulin used to create drugs.

1. A transgenic mouse that produces hybrid antibodies containing human variable regions and mouse constant regions, wherein said 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.

EP2264163 (EP1360287 also asserted).  If I understand this correctly, mice were first generically modified to contain DNA sequences for creating the human antibody.  However, those mice died easily and so the researchers added back some amount of murine (mice) DNA.  With just the right mix, the mice lived well and also produced antibodies that could be given to humans without triggering a human anti-mouse antibody response (HUMA).

UK statutory law requires:

The specification of an application shall disclose the invention in a manner which is clear enough and complete enough for the invention to be performed by a person skilled in the art.

14(3) of the UK Patents Act 1977 (Replicating the EPC Article 83). In the UK and Europe, courts have also used the undue-experimentation test and have also considered whether a skilled person would need create a follow-on invention in order to practice the invention.

Typically a claimed “range” in patent law is thought of as a numerical spread with the claim covering all potential embodiments in-between.  The full-scope of a claimed range must be enabled, and this is a common attack-point for defendants.  Here, the claims do not specify such a range, but the defendant was able to characterize the claimed replacement regions as constituting a wide swath of potential transgenic mice — thus a range (“range of products”).  The Supreme Court agreed here that it is the full scope of claimed “range of products” that must be enabled.

In the case, the trial court sided with the defendants — holding that “the teaching in the patent did not enable any type of mouse within the range to be made, let alone mice across the whole of the relevant range.” (quoting here from the Supreme Court opinion).  The appellate court disagreed — finding that the claim did enable something within the claimed scope — and that the disclosure was sufficient because the invention was inventive and groundbreaking.

Finally, at the Supreme Court, the Lord Justices followed a third path – that ultimately resulted in the claims being invalid. Like the appellate court, the Supreme Court agreed that some embodiments covered by the claim were enabled.  However, the court ruled that “some embodiments ” was not enough.

Patentees are free to choose how widely to frame the range of products for which they claim protection. But they need to ensure that they make no broader claim than is enabled by their disclosure.

A claim which seeks to protect products which cannot be made by the skilled person using the disclosure in the patent will, subject to de minimis or wholly irrelevant exceptions [such as the length of a mouse’s tail], be bound to exceed the contribution to the art made by the patent, measured as it must be at the priority date.

Enablement across the scope of a product claim is not established merely by showing that all products within the relevant range will, if and when they can be made, deliver the same general benefit intended to be generated by the invention, regardless how valuable and ground-breaking that invention may prove to be.

Id. In applying these principles to the Regeneron patents, the court found that the wide-range of potential products claimed were not sufficiently disclosed. In particular, the claimed range of products included transgenic mice with long segments of the human variable region gene locus.  But, the specification only taught how to do this with short-segments.  Invalid.

8 thoughts on “Sufficiency of a Range: UK Supreme Court

  1. 2

    Enablement reform in exchange for eligibility reform seems like something that Big Tech could get behind. I wish they’d put that on the table, to get the reformers response on the record.

    1. 2.1


      This was ‘attempted’ – but under a misinformation campaign and Trojan-Horse style in order to solely throw the eligibility reform efforts off of the rails.

      There is absolutely ZERO need to stop reform efforts on the messed up eligibility front in order to tie in ANY other issue.

    2. 2.2

      The Coons/Thillis proposed amendment was to some extent this– it included amendments to both 101 and to 112. Mainly, overbroad functional claiming would survive the amended 101 but would be likely to get caught up in the amended 112(f) and thus either substantially narrowed or invalidated. The effect would be to move invalidation of broad functional claiming away from 101 and towards 112.

      You can read the typical responses here: link to

      (I actually think the proposed 112 amendments are basically just embracing where the Fed. Cir has gotten to/is getting to anyway since Citrix).

      1. 2.2.1

        I’m not sympathetic to those responses (there’s a Black Knight quality to that side. Having lost an arm, it’s not “’tis but a scratch” but “I’m stronger than ever and I have no reason to compromise!”), but I do understand why people could be uncomfortable with the enforcement of 112(f). For one it’s hard to say how it’ll really shake out.

        Strict enforement of enablement is probably easier to project the results of, and thus could be more palatable to those who have enough sense to see the need for compromise.


          Enough sense….

          How about enough sense NOT to conflate and FIRST fix a known and recognized problem (recognized by members of all three branches of the government)?

          Inserting “compromise” when NO such thing is of note in the problem to be solved is NOT inte11ectually honest.

      2. 2.2.2

        The problem (with the proposed 112 ‘solution’) was FAR more extensive than what you seem to want to portray here.

      3. 2.2.3

        KS4, it seemed to me that the 112(f) amendment in the draft Coons/Thillis proposed bill was a not particularly well thought out, and potentially ambiguous, afterthought addition to legislation directed primarily to medical diagnostics patenting, which is being impeded by only one aspect of Sup. Ct. 101 decisions and not relevant to most other patenting. In any case, it was DOA with Congressional medical cost increases concerns and Coons-announced refusals [of those with lobbying influence] to compromise.

  2. 1

    Readers, I commend to you the “Guest Post” by Paul Cole on the case, in the blog of a well-known US patent law firm. Cole includes a Link to the “Cargo Cult Science” speech of Richard Feynman to CalTech students in 1974. Well worth a read.

    link to

    You couldn’t wish for a more finely balanced case than this. The appeal ct reversal was penned by one of England’s most respected and experienced patent law judges, and there was at the Supreme Ct a dissent opinion.

    As Paul Cole points out, it was unfortunate for the patent owner that the single worked Example of the claimed invention did not work. Perhaps the Applicant filed too early? But, boy, it was a close-run thing.

Comments are closed.