An inventor’s subjective belief that a reference is immaterial to patentability may not defeat a finding of intent to deceive. Aventis Pharma S.A. v. Hospira, Inc., 675 F.3d 1324, 1333–34 (Fed. Cir. 2012). In Aventis, the Federal Circuit affirmed the district court’s finding that Aventis’s patents were unenforceable for inequitable conduct because references withheld by the inventor were necessarily but-for material to the patentability of the claimed inventions. Moreover, the Federal Circuit held that an inventor’s incredible testimony relating to his belief of a reference’s relevance to patentability may support a finding of an intent to deceive.
The Aventis patents relate to the administration of docetaxel, a chemotherapy drug, which belongs to a class of compounds known as taxanes. Because taxanes have low solubility in water, they are often mixed with additives for stabilization. Previous taxane preparations caused serious side effects, including anaphylactic shock and ethanol intoxication. Two of Aventis’s patents describe (1) taxane compounds, including a perfusion that avoids anaphylactic and alcohol intoxication manifestations; and (2) taxane compounds with reduced ethanol.
In Aventis, the inventor did not disclose two references to the United States Patent and Trademark Office (USPTO): (1) Guéritte-Voeglein, which stated “[m]oreover Taxotere (13a) showed a better solubility in excipient system (polysorbate 80/ethanol, 1:1) . . . .”; and (2) Dictionnaire Vidal, which disclosed using polysorbate 80 as a surfactant with the cancer drug etoposide. The inventor testified, however, that he had reviewed an early draft of the Guéritte-Voeglein reference, which did not include the statement describing the polysorbate 80/ethanol excipient system, and concluded that the reference was not relevant to patentability. He also testified that the etoposide-type experiments his team attempted with doxcetaxel failed to demonstrate certain stabilities, and, thus, it was unnecessary to disclose the Dictionnaire Vidal reference to the USPTO. Upon finding that the inventor’s testimony was incredible, the district court held that the inventor intentionally withheld material references from the USPTO.
On appeal, the Aventis court deferred to the district court’s credibility determinations. The Federal Circuit noted, however, that the district court had not relied solely on its credibility determination, but rather had viewed the inventor’s testimony in light of other evidence, including the fact that the inventor himself approved the Guéritte-Voeglein reference for publication and had testified that he reviewed the article with “some care” before publication. Considering the evidence that supported a finding of specific intent to deceive, combined with its deference to the district court, the Federal Circuit upheld the district court’s decision that the two Aventis patents were unenforceable for inequitable conduct.
The Federal Circuit focused on its decision in Therasense, Inc. v. Becton, Dickinson & Co., 649 F.3d 1276 (Fed. Cir. 2011), as the standard for proving inequitable conduct. Under Therasense, a defendant must establish both but-for materiality of the withheld reference and an intent to deceive. But-for materiality is established if the USPTO would not have allowed the claim if it had been aware of the reference. To establish intent to deceive, the accused infringer must demonstrate that the applicant knew of the reference, knew it was material, and made a deliberate decision to withhold it. The court noted that Therasense marked a change in inequitable-conduct jurisprudence, rejecting the “sliding-scale” approach, where inequitable conduct could be proved with a weak showing of intent and a strong showing of materiality, or vice versa. Although the district court did not have the benefit of the Therasense opinion, it found the withheld references constituted but-for material prior art and made distinct intent and materiality findings, rather than using the pre-Therasense sliding-scale approach.
Aventis therefore may indicate that the materiality of a reference inevitably informs a court’s analysis of intent and, in some cases, may be more important than the stated intent of a party. Based upon the Aventis decision, patent attorneys should carefully review and submit all relevant prior art to the USPTO during the patent-application process, refraining from relying solely on inventors to self-select prior art for the USPTO. As shown in Aventis, an inventor’s subjective belief that a reference is immaterial may not preclude a finding of inequitable conduct.