It appears that the announced death of inequitable conduct claims may have been premature. As described below, yet another court allowed such claims to survive summary judgment.
A court in the Northern District of Illinois denied summary judgment on the plaintiff's motion for summary judgment of no unenforceability. Citing the Federal Circuit's recent decision in Therasense v. Becton, Dickinson & Co., 2011 WL 2028255 (Fed. Cir. May 25, 2011), the court reiterated the new, heightened standard for proving inequitable conduct that to prevail on such a claim, "the accused infringer must prove by clear and convincing evidence that the applicant knew of the [prior art] reference, knew that it was material, and made a deliberate decision to withhold it." Slip Op. at 15. Moreover, "merely proving that the applicant should have known of the reference's materiality is insufficient. Though a district court may infer intent from indirect and circumstantial evidence, in order to meet the clear and convincing evidence standard, the specific intent to deceive must be 'the single most reasonable inference able to be drawn from the evidence.'" Id. Finally, the accused infringer must prove that the omitted reference is but-for material by showing that the PTO would not have allowed the claim had it been aware of the undisclosed prior art. Id.
The accused infringer claimed that the patentee engaged in inequitable conduct during the prosecution of the patent-in-suit by improperly adding new matter by: (1) submitting an incorrect English translation of the international application; (2) representing to the USPTO that no new matter had been added to the substitute specification filed with the USPTO; and (3) representing that the substitute specification had been provided as required by the Examiner and omitting the proper substitute specification.