Inequitable conduct is frequently raised as a defense to patent infringement. (One academic study contends that as many as 80 percent of federal patent suits include an assertion of inequitable conduct.) The doctrine of inequitable conduct originates in USPTO Rule 56, which details the duty to disclose material information placed upon the inventors and other individuals substantially involved in the preparation or prosecution of a patent application. On May 25, 2011, the U.S. Court of Appeals for the Federal Circuit issued an en banc opinion in Therasense, Inc. v. Becton, Dickinson & Co. which significantly tightened the standards for both intent and materiality that courts must use to find a patent unenforceable for inequitable conduct.
Intent:Now “…the accused infringer must prove that the patentee acted with the specific intent to deceive the PTO”… proving “by clear and convincing evidence that the applicant knew of the reference, knew that it was material, and made a deliberate decision to withhold it.”
Materiality: Prior to the Therasense decision, courts were allowed to measure intent on a sliding scale, i.e., the more material a reference, the less evidence required to prove intent to deceive, and vice versa, in effect treating the proof as a zero-sum game. The “sliding scale” exists no more. The Federal Circuit explained, “a district court should not use a ‘sliding scale,’ where a weak showing of intent may be found sufficient based on a strong showing of materiality, and vice versa. Moreover, a district court may not infer intent solely from materiality…a court must weigh the evidence of intent to deceive independent of its analysis of materiality.”
Clearly the USPTO thinks this decision is a game-changer, especially with respect to Rule 56. They followed the release with one of their own:
Press Release, 11-36
USPTO Studying Therasense v. Becton, Dickinson Decision to Assess Impacts on Agency Practice and Procedures; Expects to Issue Further Guidance to Applicants Soon
Washington– Today the United States Patent and Trademark Office (USPTO) announced that it is carefully studying the important en banc decision by the U.S. Court of Appeals for the Federal Circuit in the case of Therasense v. Becton, Dickinson to assess how it may impact agency practices and procedures. The agency also announced that it expects to soon issue guidance to applicants related to the prior art and information they must disclose to the Office in view of Therasense. “We are now studying the potential impact of Therasense v. Becton, Dickinsonon Office practice, and we expect to soon issue guidance to applicants regarding the materials they must submit to the Office under their duty of disclosure,” said Under Secretary of Commerce for Intellectual Property and Director of the USPTO David Kappos. The Therasense decision concerns the standards for inequitable conduct, including the materiality and intent prongs. The Court’s decision resolves uncertainties in many aspects of how district courts must apply the inequitable conduct doctrine. It also directly affects applicant behavior in front of the USPTO and, in particular, their disclosure of information relevant to the patentability of their inventions.