Landmark UK Supreme Court Decision Invalidates Regeneron Patent Claims

Cambridge, UK; 24 June, 2020: Kymab, a clinical-stage biopharmaceutical company developing fully human monoclonal antibody therapeutics, is pleased to announce that the Supreme Court of the United Kingdom has held that all of the claims of two patents (European Patents EP(UK) 1 360 287 and EP(UK) 2 264 163, the ‘Murphy patents’) owned by Regeneron Pharmaceuticals Inc that were asserted against Kymab are invalid. The Court’s decision upholds the February 2016 decision of the High Court trial judge, Mr. Justice Henry Carr to revoke the claims and reverses the Appeal Court’s determination that they were valid. 

A five-member panel of the Supreme Court heard arguments on the 11th and 12th of February 2020 and announced their decision today, 24th of June 2020. It was held that the relevant claims of the Murphy patents were invalid for insufficiency because they did not enable the ordinary skilled person to work the claimed invention across the breadth of the claims, in line with established jurisprudence of the UK courts and European Patent Office. The Supreme Court noted that Kymab’s ability to create transgenic mice with the entire human antibody variable region depended upon Kymab’s own inventions made separately after the priority date of the Murphy patents.

“We are grateful that the Court has recognized the shortcomings of the Regeneron patents and reinforced the established law that requires that an invention is adequately enabled across its scope”, said Simon Sturge, Chief Executive Officer of Kymab. He added “Kymab’s IntelliSelect® platforms continue to generate best‑in‑class, fully human monoclonal antibodies, underpinned by our extensive IP estate.”

“This case raised fundamentally important questions of patent law relevant to a wide variety of innovative life science companies in the UK” said Dr. Penny Gilbert, partner at Powell Gilbert LLP. “The Supreme Court has confirmed that patents should not be available for inventions that are not adequately enabled. Kymab has shown tremendous resilience in defending this case since Regeneron commenced proceedings in September 2013 and we are pleased to have helped them achieve this great result.”

The Murphy patents sought to cover genetically modified mice containing chimeric human-mouse antibody genes and the human antibodies made using such mice. The European Patent Office had previously upheld the patents but had not considered evidence that was available to the UK Courts. Counterparts of the Murphy patents have also been litigated by third parties in the US where an equivalent Murphy patent was found to be invalid. 

Kymab’s patent estate provides protection in the United States, Europe, Japan and other globally important commercial markets for human antibody therapeutics. Kymab’s patents cover human antibodies produced using transgenic platforms that employ chimeric human-mouse antibody genes. In September 2019 and January 2020, Regeneron filed requests at the US Patent Office’s PTAB (Patent Trial & Appeal Board) seeking Inter Partes Review (IPR) proceedings against 5 of Kymab’s US patents. The PTAB rejected all 5 petitions filed by Regeneron leaving each patent and their claims in full force in the US. Regeneron filed oppositions against Kymab’s Japanese patents, but these patents were upheld in unappealable decisions by the Japanese Patent Office. In August 2019 the Australian Patent Office (IP Australia) rejected on all grounds an opposition by Regeneron against Kymab’s patent protecting therapeutic antibodies produced from transgenic mouse platforms. Regeneron appealed to the Australian Federal Court, but in May 2020 Regeneron agreed to dis­continue its appeal and Kymab’s Australian patent is now upheld and in force.



About Kymab

Kymab is a clinical-stage biopharmaceutical company developing a deep pipeline of novel antibody-based therapies in a broad range of indications. The Company generates its product candidates using its proprietary, integrated platforms collectively called IntelliSelect®. Kymab’s platforms have been designed to maximize the diversity of human antibodies produced in response to immunization with antigens. Selecting from a broad diversity of fully human antibodies allows for the identification of antibodies with optimal drug-like properties.

For more information on Kymab please see

Forward-looking statements

This announcement includes forward-looking statements that involve risks, uncertainties and other factors, many of which are outside of our control, that could cause actual results to differ materially from the results discussed in the forward-looking statements. Forward-looking statements include statements concerning our plans, objectives, goals, future events, performance and/or other information that is not historical information. All such forward-looking statements are expressly qualified by these cautionary statements and any other cautionary statements which may accompany the forward-looking statements. We undertake no obligation to publicly update or revise forward-looking statements to reflect subsequent events or circumstances after the date made, except as required by law.

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Brandon Lewis
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Media UK

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