Company News: Merus Prevails in Inequitable Conduct Case Against Regeneron

Court ruling further strengthens Merus’ freedom to operate in using transgenic mice for therapeutic human antibodies

Merus, a leader in developing best-in-class bispecific antibody therapeutics to treat cancer patients, today announced that it won its inequitable conduct trial against Regeneron. In a decision issued on Thursday, August 6, Judge Katherine B. Forrest of the U.S. District Court for the Southern District of New York indicated that Regeneron engaged in inequitable conduct in connection with obtaining U.S. Patent No. 8,502,018. This marks the third counterclaim upon which Merus has prevailed in this litigation, initiated by Regeneron. In December 2014, Regeneron conceded that Merus does not infringe any claim of the ‘018 patent, and that the patent is invalid in view of the Court’s prior decision on claim construction. Given the Court’s ruling on August 6, Regeneron’s patent has now been adjudged to be not infringed, invalid and unenforceable for being procured by inequitable conduct.

In that decision, the Court noted that Regeneron’s agents had withheld material information from the United States Patent Office (USPTO) during prosecution of the ‘018 patent. The Court further concluded that an adverse inference that Regeneron’s employees intentionally mislead the U.S. Patent Office was appropriate and “that Regeneron engaged in inequitable conduct in connection with the prosecution of the ‘018 patent.”