PHARMACEUTICAL IP

  • Offering
    • Evolve AI
      • Albert
        • Validity analysis
        • Albert Construe
      • Popper
      • Franklin
    • Fractional IP counsel
    • Services
      • AI guidance
      • Competitive intelligence
      • Deals
      • Due diligence
      • Freedom to operate
      • IP strategy and communication
      • Oppositions and appeals
      • Patent drafting
      • Patent prosecution
      • Trade secrets
    • Technologies
      • Pharmaceuticals
      • Biologics
      • Cell & gene therapy
      • AI drug discovery
    • Our clients
      • Biotech
      • CROs and CMOs
      • Established pharma
      • International IP counsel
      • Investors
      • Start-ups
      • Universities
  • Fractional IP counsel
    • What is fractional IP counsel?
    • Biotech
    • CROs and CMOs
    • Established pharma
    • International IP counsel
    • Investors
    • Start-ups
    • Universities
  • Evolve AI
    • Albert
      • Validity analysis
      • Albert Construe
    • Popper
    • Franklin
  • Technologies
    • Pharmaceuticals
      • Dosing regimens
      • Formulations
      • Life cycle management
      • New indications
      • Platform technologies
    • Biologics
      • Antibodies
      • Antibody-drug conjugates (ADCs)
      • T cell engagers (TCEs)
    • Cell & gene therapy
      • CAR-T cell therapies
      • Gene therapies
      • In vivo CAR-T
      • Lipid nanoparticles (LNPs)
      • Macrophages (CAR-M)
      • mRNA therapeutics
      • Regenerative cell therapies
    • AI drug discovery
  • Insights
    • Articles
    • Pharma IP Toolkit
    • Evolve Guides
    • Events & Webinars
    • Subscribe
  • About us
    • Our team
    • Recognition
    • Join us
    • Contact us
  • Offering
    • Evolve AI
      • Albert
        • Validity analysis
        • Albert Construe
      • Popper
      • Franklin
    • Fractional IP counsel
    • Services
      • AI guidance
      • Competitive intelligence
      • Deals
      • Due diligence
      • Freedom to operate
      • IP strategy and communication
      • Oppositions and appeals
      • Patent drafting
      • Patent prosecution
      • Trade secrets
    • Technologies
      • Pharmaceuticals
      • Biologics
      • Cell & gene therapy
      • AI drug discovery
    • Our clients
      • Biotech
      • CROs and CMOs
      • Established pharma
      • International IP counsel
      • Investors
      • Start-ups
      • Universities
  • Fractional IP counsel
    • What is fractional IP counsel?
    • Biotech
    • CROs and CMOs
    • Established pharma
    • International IP counsel
    • Investors
    • Start-ups
    • Universities
  • Evolve AI
    • Albert
      • Validity analysis
      • Albert Construe
    • Popper
    • Franklin
  • Technologies
    • Pharmaceuticals
      • Dosing regimens
      • Formulations
      • Life cycle management
      • New indications
      • Platform technologies
    • Biologics
      • Antibodies
      • Antibody-drug conjugates (ADCs)
      • T cell engagers (TCEs)
    • Cell & gene therapy
      • CAR-T cell therapies
      • Gene therapies
      • In vivo CAR-T
      • Lipid nanoparticles (LNPs)
      • Macrophages (CAR-M)
      • mRNA therapeutics
      • Regenerative cell therapies
    • AI drug discovery
  • Insights
    • Articles
    • Pharma IP Toolkit
    • Evolve Guides
    • Events & Webinars
    • Subscribe
  • About us
    • Our team
    • Recognition
    • Join us
    • Contact us
  • Offering
  • What is fractional IP counsel?
  • Evolve AI
  • Technologies
  • Insights
  • Our team
  • Offering
  • What is fractional IP counsel?
  • Evolve AI
  • Technologies
  • Insights
  • Our team

BREAKING: Kymab caught the mouse as sufficiency strengthened by UK Supreme Court in Regeneron battle ([2020] UKSC 27)

  • Technology: Biologics
  • 22nd September 2020
The UK Supreme Court today found Regeneron's valuable antibody platform technology patents invalid for insufficiency. In doing so, the UK Supreme Court overturned the Court of Appeal decision and confirms the strong sufficiency requirement in the UK. The Supreme Court decision places emphasis on the principle of sufficiency that a patent claim should be enabled across its whole scope.
Gold ribbon twisting once to reveal a turquoise underside on dark blue, Evolve abstract article image

Originally posted on IPKat.

The UK Supreme Court today found Regeneron’s valuable antibody platform technology patents invalid for insufficiency. In doing so, the UK Supreme Court overturned the Court of Appeal decision and confirms the strong sufficiency requirement in the UK. The Supreme Court decision places emphasis on the principle of sufficiency that a patent claim should be enabled across its whole scope. As summarised by the UK Supreme Court itself, the Court of Appeal reasoning was seen as increasing the rewards obtainable by inventors in a complex, rapidly developing field like genetic engineering. The Supreme Court found in a majority ruling that the Court of Appeal swayed the balance too much in favour of patentees in a way that was not warranted by UK or EPO law. The full UK Supreme Court judgment can be read here.

Case Background

The Regeneron patents in question (EP2264163 and EP1360287) related to mice genetically modified to possess human antibody genes. Historically, the development of therapeutic antibodies relied on the cloning of specific human antibody genes into a mouse. The Regeneron mice (VelocImmune) produce human antibodies that respond naturally to antigenic challenge and thus mirror the normal immune reaction. This allows production of a diverse spectrum of antibodies against the same target within a single mouse.

Regeneron brought proceedings against the Cambridge-based biotech company Kymab for infringement of the VelocImmune patents. Kymab counterclaimed that the patents were invalid for insufficiency. In the High Court, the late Mr Justice Heney Carr agreed with Kymab that the claims were insufficient. The High Court decision was based on evidence that the one example in the patent of how to make the claimed mouse would not have worked. Particularly, the method required the insertion and deletion of large sections of DNA. Such a method was not possible at the priority date. The High Court thus concluded that the patent did not enable mice falling under the claims to be made.

Kymab appealed to the Court of Appeal. The Court of Appeal disagreed with the High Court, and found the patents sufficiently disclosed. Lord Justice Kitchin (as then was) agreed with the High Court that the example provided in the patent would not have worked. However, Lord Justice Kitchin (as then was) found that a skilled person was not bound to follow the examples provided in the patent. Instead, the skilled person could use common general knowledge to make obvious changes to the method. This would allow a skilled person to make a mouse falling under the scope of the claims. A skilled person would not be able to make all types of mice falling under the scope of the claims. However, the ability of the skilled person to make at least one type of mouse according to the invention amounted to sufficiency of disclosure, given that the invention related to a broad general principle.

The Court of Appeal reasoned that if the patented invention related to a general principle of usefulness across a range of potential product types, it is not necessary for the patent to enable production of all of these product types. If the patentee was limited to a monopoly over only the products that could be immediately made, this would deprive the patentee of any reward for the broader applicability of their invention. Importantly, the types of mice that now represent the most valuable commercial embodiment of the invention could not have been made at the priority date, and required further inventions to be realised. However, for Lord Justice Kitchin, the broad general contribution represented by the patent should none-the-less be rewarded.

UK Supreme Court Decision

In a majority judgment, the UK Supreme Court found the Court of Appeal’s reasoning logically sound, but ultimately considered it to be inconsistent with the UK and EPO law on insufficiency. In particular, the UK Supreme Court understood the principle that a patent should enable substantially all products within the scope of a claim at the priority date to be part of the bedrock of both UK and EPO law. In the words of Lord Briggs, who led the majority judgment, “[t]o 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, and which would exceed by a wide margin the scope for the development of the law by judicial decision-making in a particular Convention state”.

The Supreme Court thus did not think the patent bargain was satisfied if the benefits of an invention could only be realised after the priority date, if and when all embodiments within the range could be made. Kymab’s appeal was therefore upheld, and the Regeneron patents found invalid for insufficiency.

In a dissenting view, Lady Black first noted agreement between the Court of Appeal and Supreme Court on the legal principles. For Lady Black, the two courts disagreed in the application of these principles to the case in question. Contrary to the Supreme Court majority, Lady Black agreed with the Court of Appeal that the invention related to a broad general principle, that this principle was employed in all mice across the range of the claim, and that the patent should be rewarded by a commensurate broad scope of protection.

So are the UK and EPO Boards of Appeal currently aligned on sufficiency? The answer to this question is not straightforward, and we will provide some further thoughts in coming days.

Author: Rose Hughes

Rose Hughes

Rose is a biotech and pharmaceutical patent specialist with over a decade of experience in intellectual property. Rose is a Patent Director at Evolve, where she leverages our unique fractional in-house model to provide clients with deep patent law expertise combined with the strategic commercial oversight typically associated with senior in-house counsel.

With a PhD in Immunology from UCL, Rose applies her technical background to complex innovations in biologics, cell and gene therapies, and the rapidly emerging field of AI-assisted drug development. Previously, Rose held the role of Director, Patents at AstraZeneca, where she was responsible for global IP portfolios and IP strategy at every stage of the pharmaceutical pipeline, from platform development and on-market commercialisation to SPCs and patent term extensions.

A recognised thought leader in the field, Rose has been a regular contributor to IPKat since 2018, offering practical insights into European patent law developments. She is also a frequent speaker on the epi podcast, a guest lecturer for the Brunel University IP law Postgrad Certificate, and a contributing author to published books A User’s Guide to Intellectual Property in Life Sciences (2021) and Developments and Directions in Intellectual Property Law (2023).

Related insights...

Single cut gold stone glowing turquoise at its heart on dark blue, Evolve abstract article image
Single cut gold stone glowing turquoise at its heart on dark blue, Evolve abstract article image

Prophetic prior art and the common light chain mouse (T 0527/24)

  • 1st November 2026
Kymab is famous as the Cambridge antibody mouse company that fought Regeneron all the way to the UK Supreme Court, and won, on sufficiency (no mean feat, given the very strict approach the UK courts have taken to the sufficiency test for pharmaceutical inventions in recent years). In T 0527/24, Kymab was on the other…
Stack of gold plates fanning open around a turquoise light on dark blue, Evolve abstract article image
Stack of gold plates fanning open around a turquoise light on dark blue, Evolve abstract article image

Claim construction checkpoints: Application as filed versus granted patent (T 0715/24)

  • 16th September 2026
G 1/24 requires that the description must always be “consulted” to interpret a claim. The question remains whether a definition in the description can override an otherwise clear meaning in the claims. In T 0715/24, Bristol-Myers Squibb (BMS) sought to persuade the Board of Appeal that a negative feature, read together with a paragraph of…
Gold antibody shape with one glowing turquoise arm tip on dark blue, Evolve abstract article image.
Gold antibody shape with one glowing turquoise arm tip on dark blue, Evolve abstract article image.

Be careful what you wish for: Method of treatment claim for an antibody genus found to satisfy both written description and enablement requirement (Teva v Eli Lilly)

  • 3rd July 2026
In a remarkable departure from what we might have expected it to do following Amgen v Sanofi, the US Court of Appeals for the Federal Circuit in Teva v Eli Lilly upheld a jury verdict finding that a method of treatment claim for a broad genus of antibody satisfied both the written description and enablement…
Nested gold frames with a glowing turquoise centre on dark blue, Evolve abstract article image
Nested gold frames with a glowing turquoise centre on dark blue, Evolve abstract article image

Human definitions versus biological reality (T 630/24)

  • 16th June 2026
As the recent furore over claim interpretation and description amendments illustrates, patent attorneys love nothing more than to argue about the meaning of words. As we know, words are contextual things, and can shift their meaning depending on the words around them and the perspective of the reader. Definitions are particularly unstable in biological sciences,…
Straight gold ladder with one glowing turquoise rung on dark blue, Evolve abstract article image.
Straight gold ladder with one glowing turquoise rung on dark blue, Evolve abstract article image.

Sequence identities and functional definitions – where is the limit? (T 0137/24)

  • 2nd June 2026
Biotechnology patents often rely on defining protein and nucleic acid features by their sequence identity. However, it is often not necessary to define the exact sequence, but instead to define the sequence according to a limit of sequence identity, e.g. a sequence having a 90% sequence identity to a specified sequence.
Gold bar carrying turquoise cubes on slender stalks on dark blue, Evolve abstract article image.
Gold bar carrying turquoise cubes on slender stalks on dark blue, Evolve abstract article image.

Strict US written description and enablement requirement applied to ADCs and platform inventions (Seagen v Daiichi Sankyo)

  • 14th December 2025
The recent decision of the US Court of Appeals for the Federal Circuit in Seagen v Daiichi Sankyo overruled the jury decision in the District Court to find an ADC linker platform patent invalid for both lack of written description and enablement. 
Gold band splitting into three branches at a turquoise junction on dark blue, Evolve abstract article image
Gold band splitting into three branches at a turquoise junction on dark blue, Evolve abstract article image

UPC Court of Appeal tackles broad functional antibody claims (UPC_CoA_529/2024)

  • 4th December 2025
The global litigation saga involving Amgen’s PCSK9 antibodies has long served as a high-stakes test case for jurisdictional approaches to broad, functionally defined antibody claims. Following the US Supreme Court’s landmark finding of lack of enablement in Amgen v Sanofi, and the UPC Munich Central Division’s initial revocation of the equivalent European patent, all eyes…
Gold strands braiding into one cord with a turquoise join on dark blue, Evolve abstract article image
Gold strands braiding into one cord with a turquoise join on dark blue, Evolve abstract article image

EPO pharma case law trends 2025: Antibodies and biologics

  • 19th November 2025
The science of biologics is rapidly progressing, with the development of ever more complex protein structures, incorporation of molecules into cell therapies and the increasing use of AI-assisted design and in silico modelling. Patent law must respond to these new challenges. What better time to take a look at the trends from the EPO case…
Straight gold ladder with one glowing turquoise rung on dark blue, Evolve abstract article image.
Straight gold ladder with one glowing turquoise rung on dark blue, Evolve abstract article image.

Alexion’s Soliris sequence error saga (Alexion v Samsung Bioepis [2025] EWHC 1240)

  • 4th June 2025
Beware! The recent Samsung v Alexion UK High Court decision reveals that even a single-letter error in patent sequence data, coupled with vague descriptive language, can invalidate your claims and lead to costly legal battles.
Gold antibody shape with one glowing turquoise arm tip on dark blue, Evolve abstract article image.
Gold antibody shape with one glowing turquoise arm tip on dark blue, Evolve abstract article image.

First UPC decision to tackle infringement and validity of second medical use claims (Sanofi v Amgen, UPC_CFI_505/2024)

  • 19th May 2025
Understand the UPC’s first ruling on second medical use patents, which clarifies novelty and infringement standards but creates new hurdles for patentees, especially concerning “skinny labelling” and proving off-label use.
All Insights

evolve® is a trading entity of Evolve Intellectual Property Limited. Evolve Intellectual Property Limited is regulated by the Intellectual Property Regulation Board (IPReg). Details of the UK professional rules can be found on the IPReg website

registered address: 49 Greek Street, London, England, W1D 4EG

website out of house

© 2026 All Rights Reserved

Keep in touch

  • Subscribe
  • Contact us
  • Cookie Notice
  • Subscribe
  • Contact us
  • Cookie Notice