Sanofi/Regeneron Move for Summary Judgment of Invalidity in Dupixent® Patent Litigation

Last week, in the ongoing Immunex v. Sanofi patent litigation regarding Immunex’s claims of infringement against Sanofi and Regeneron’s Dupixent® (dupilumab) product, the Defendants moved for summary judgment of invalidity of the sole patent-in-suit, the ‘487 patent, on the ground that the patent’s claims are indefinite.

According to Defendants’ brief, “[t]he sole independent claim of the ʼ487 Patent claims an entire genus of antibodies entirely by their function: ‘An isolated human antibody that competes with a reference antibody for binding to human [IL-4R], wherein’ the light and heavy chains of the ‘reference antibody’—not the claimed ‘isolated human antibod[ies]’—include the amino acid sequences found in ‘SEQ ID NO:10’ and ‘SEQ ID NO:12.'”  Defendants argue that the claim term “competes” is indefinite, rendering the claims invalid, because there is no dispute that several different techniques exist for assessing competition that can yield discordant results, and the patent fails to provide any guidance about what “compete” means in the claims.  Defendants further argue that the type of functional claim language in the patent—defining an antibody solely by how it “competes” with other antibodies, instead of by its structure—requires the patent’s specification to disclose a structure that is associated with that function in order to be sufficiently definite.  Defendants contend that the patent does not meet that requirement.

A hearing is currently scheduled for March 12, 2018.  Stay tuned to Big Molecule Watch for further developments.