Kymab holds off Regeneron in patent fight on home turf

Chalk one up for antibody maker Kymab. The U.K. Supreme Court invalidated a pair of Regeneron patents around antibody-producing mice, putting to rest a lawsuit Regeneron filed against Kymab seven years ago.

Known as patents ‘287 and ‘163, or the “Murphy patents,” they sought to cover genetically modified mice that contain chimeric human-mouse antibody genes, as well as human antibodies made using those mice. Regeneron sued Kymab in U.K. High Court in 2013 alleging that its Kymouse technology infringed patents covering its Velocimmune platform.

The Supreme Court upheld 4-1 the decision of a High Court from 2016 to revoke Regeneron’s claims, reversing an Appeals Court’s verdict that the patents were valid.

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“Regeneron’s patents did not enable a skilled person to make mice containing more than a very small section of the human variable region,” the Supreme Court said in a press summary. “The amount of human material was an important factor which was thought to affect the diversity of useful antibodies which the mice would produce. Mice at the more valuable end of the range could not be made using Regeneron’s patents. So Regeneron was claiming a monopoly which was far wider than its contribution to the art.”

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In its judgment, the court noted that Regeneron and Kymab’s ability to make transgenic mice depended upon “further (and different) inventions separately made by each of them some years 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 Kymab CEO Simon Sturge in a statement, adding: “Kymab’s IntelliSelect platforms continue to generate best‑in‑class, fully human monoclonal antibodies, underpinned by our extensive IP estate.”

The U.K. verdict is just the latest in a string of decisions that have come down on Kymab’s side. In April, the U.S. Patent and Trademark Office’s Trial and Appeal Board shut down a request from Regeneron to invalidate four Kymab patents. And that decision followed similar ones from patent offices in Japan and Australia—the Japanese Patent Office upheld Kymab’s patents in unappealable decisions, while IP Australia rejected Regeneron’s opposition to a Kymab patent on all grounds. Regeneron has appealed the latter decision.

For its part, Regeneron emphasized that the Supreme Court decision applies only within the U.K.

"The decision renders the two patents invalid and revoked in the UK only. Regeneron’s rights
concerning these patents in other European jurisdictions remain in full force and effect," the company said in a statement. "The 287 patent validity was upheld at the Europe-wide level by the Technical Board of Appeal of the European Patent Office (“EPO”) in 2015, and the 163 patent validity was upheld by EPO Opposition Division in 2018. Proceedings before the EPO’s  Technical Board of Appeal on the 163 patent are ongoing.