Overview
On May 25, 2011, the Federal Circuit issued its en banc opinion in Therasense, Inc. v. Becton, Dickinson and Co., radically changing the legal landscape of the inequitable conduct doctrine. In creating these new standards, the Therasense majority aimed to balance the competing goals of encouraging honesty of applicants before the United States Patent & Trademark Office (“PTO”) and setting a logistically appropriate standard for determining whether inequitable conduct occurred. The majority stressed that the “low standards for intent and materiality” set in its previous opinions coupled with the harsh consequences of inequitable conduct have resulted in “unintended consequences.” Specifically, under the old standards, “allegations of inequitable conduct are routinely brought on the slenderest grounds” and “patent prosecutors regularly bury PTO examiners with a deluge of prior art references, most of which have marginal value.” To address these concerns, the majority tightened the requirements for findings of both materiality and intent to deceive.
Changes in Legal Standard
Under the old standard, in order to invalidate a patent, the party alleging inequitable conduct had to show “clear and convincing evidence that the applicant (1) made an affirmative misrepresentation of material fact, failed to disclose material information, or submitted false material information [to the PTO], and (2) intended to deceive the [PTO].” Cargill, Inc. v. Canbra Foods, Ltd., 476 F.3d 1359, 1363-64 (Fed. Cir. 2007).
The Therasense majority first tightened the intent requirement by reaffirming previous cases stressing the need for clear and convincing evidence of specific intent to deceive. Thus, proof of negligence and gross negligence is not sufficient, and in cases of nondisclosure, the evidence must show that the “applicant knew of the reference, knew that it was material, and made a deliberate decision to withhold it.” As before, deceptive intent may inferred from indirect and circumstantial evidence. However, the specific intent to deceive must be “the single most reasonable inference able to be drawn from the evidence.” Furthermore, the patentee need not offer a good faith explanation unless the accused infringer first proves a threshold level of intent to deceive by clear and convincing evidence. Continue reading


