This case presented questions directed to what conduct could constitute inequitable conduct before the patent office and what standards should apply to prove inequitable conduct. Although the majority did not fundamentally alter the core principals of the inequitable conduct doctrine, in remanding the case to the district court, it did take steps to "tighten" a doctrine it viewed as having "plagued not only the courts but also the entire patent system." Opinion at 23.
The majority stated that “to prevail on the defense of inequitable conduct, the accused infringer must prove that the applicant misrepresented or omitted material information with the specific intent to deceive the PTO.” Opinion at 19. The majority also affirmed that both materiality and intent must be established by clear and convincing evidence. Id. Although this does not reflect a significant doctrinal change, there are significant changes made in Therasense as the “court now tightens the standards for finding both intent and materiality in order to redirect a doctrine that has been overused to the detriment of the public.”
Some highlights of this "tightening" include:
With respect to Intent:
- Because an accused infringer must establish a “specific intent to deceive the PTO,…the accused infringer must prove by clear and convincing evidence that the applicant knew of the reference, knew it was material, and made a deliberate decision to withhold it.” Opinion at 24 (emphasis added).
- “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.” Opinion at 25.
- A district court may still use indirect and circumstantial evidence to establish intent, but “the specific intent to deceive must be ‘the single most reasonable inference able to be drawn from the evidence.’…Hence, where there are multiple reasonable inferences that may be drawn, intent to deceive cannot be found.” Opinion at 26.
- “The absence of a good faith explanation for withholding a material reference does not, by itself, prove intent to deceive.” Id.
With respect to materiality:
"[T]he materiality required to establish inequitable conduct is but-for materiality. When an applicant fails to disclose prior art to the PTO, that prior art is but-for material if the PTO would not have allowed a claim had it been aware of the undisclosed prior art.” Opinion at 27.
- But, in assessing materiality, the district court should apply the reference the way an examiner would, i.e., “the court should apply the preponderance of the evidence standard and give claims their broadest reasonable construction.” Opinion at 28
- The but-for test has an exception: “When the patentee has engaged in affirmative acts of egregious misconduct, such as the filing of an unmistakably false affidavit, the misconduct is material.” Opinion at 29.
- “This court does not adopt the definition of materiality in PTO Rule 56.” Opinion at 32. Thus a reference is not "material" simply because it may be “inconsistent with a position taken by the applicant” or if it could “compel a conclusion that a claim is unpatentable…before any consideration is given to evidence which may be submitted in an attempt to establish a contrary conclusion of patentability.” Opinion at 33. The but-for materiality standard is narrower than the various incantations of Rule 56 over the years and to be satisfied, a reference must compel a finding of invalidity after all relevant evidence is considered (such as secondary considerations of non-obviousness or arguments why the rejection is improper).
(In future posts, I may discuss the concurring and dissenting opinions, but for the sake of time (mostly mine) I limited this post to the highlights of the 37 pg. majority opinion.)
