Litigation Update:  Sanofi’s Summary Judgment Motion Denied, Immunex Renews Its Motion to Stay Pending IPR in DUPIXENT Patent Litigation

Following up on our previous coverage of Immunex’s patent infringement suit against Sanofi related to Immunex’s Dupixent® (dupilumab) biologic, Judge Otero recently denied Sanofi’s motion for summary judgement of invalidity based on indefiniteness of the claim terms “competes” and “binding affinity (Ka).”

Sanofi criticized Immunex’s ’487 patent for failing to disclose any specific assay for determining whether the claimed dupilumab antibody “competes” with a reference antibody, as claimed.  The Court disagreed that the term was indefinite and adopted Immunex’s arguments that the choice of assay was inconsequential because the determination was binary—i.e., an antibody according to the claims competes with a reference antibody or it does not—and because Sanofi had not proffered evidence of a reliable test which demonstrated contradictory competition assay results.  Sanofi made similar indefiniteness arguments regarding the “binding affinity (Ka)” term based on internal testing performed by scientists at Immunex, which Sanofi argued showed irreconcilably different results depending on the choice of test protocol.  With respect to the term “binding affinity (Ka),” the Court sided with Immunex, finding that a person of ordinary skill in the art could control for any differences in determinations of dupilmab’s binding affinity.

Immunex also renewed its motion to stay the District Court proceeding pending the outcome of Sanofi’s IPR on the ’487 patent.  The parties jointly moved to expedite the briefing schedule for Immunex’s motion to stay.  A hearing on the motion to stay is set for September 17, 2018.

Stay tuned to Big Molecule Watch for additional updates.