Aventis Pharma S.A. v. Hospira, Inc.: Federal Circuit Declares Pharmaceutical Patents Unenforceable for Inequitable Conduct


Aventis Pharma S.A. v. Hospira, Inc., No. 2011-1018, 2012 WL 1155716 (Fed. Cir. April 9, 2012). Slip Opinion

The Court of Appeals for the Federal Circuit affirmed the U.S. District Court for the District of Delaware‘s holding that claim 5 of Aventis Pharma’s U.S. Patent No. 5,750,561 (filed August 4, 1993) (“the ‘561 patent”) and claim 7 of its U.S. Patent No. 5,714,512 (filed August 23, 1993) (“the ‘512 patent”) were invalid for obviousness under 35 U.S.C. § 103 and unenforceable on inequitable conduct grounds. Reviewing the district court’s factual findings for clear error and its ultimate finding of inequitable conduct for abuse of discretion, the Federal Circuit found that both patents were unenforceable for inequitable conduct, because the defendants had met their burden of showing that the withheld references were material to patentability and that the applicant intended to deceive the U.S. Patent and Trademark Office (“PTO”), primarily relying on testimony by the patents’ inventor.

PharmaPatents provides an overview of the case. Patents4Life suggests that the case may have come out differently had the inventor “professed to have no recollection” of the events which happened twenty years ago. Bloomberg Businessweek discussed the financial impact of generic drug manufacturers on Sanofi.

Aventis Pharma holds the ‘561 and ‘512 pharmaceutical patents covering compositions containing the chemotherapy cancer drug called docetaxel and marketed under the brand-name Taxotere. Taxotere belongs to a class of drugs called “taxanes,” which are administered slowly in a diluted water-based solution called a “perfusion” that contains additives to prevent taxanes from precipitating out and forming clumps. Sanofi-Aventis U.S., L.L.C. holds the New Drug Application for the drug Taxotere. After the defendants Hospira, Inc. and Apotex Inc., applied for FDA approval to market generic versions of Taxotere, Aventis and Sanofi (collectively, “Sanofi”) sued for infringement. Among other defenses, the defendants argued that the ‘561 and ‘512 patents were unenforceable on inequitable conduct grounds, because the inventor, Fabre, had failed to disclose two prior art references: the GV and Vidal references.

The Federal Circuit relied on last year’s decision in Therasense, Inc. v. Becton, Dickinson & Co., 469 F.3d 1276 (Fed. Cir. 2011), which had rejected a “sliding scale” approach to proving inequitable conduct, finding instead that the two elements of the inequitable conduct defense are “separate requirements,” and that “but-for materiality is the standard for evaluating the materiality prong of the analysis unless there is affirmative egregious misconduct.” Aventis Pharma, 2012 WL 1155716, at *7.

On the issue of but-for materiality, the court recounted the different evidentiary standards required to find patent invalidity (clear and convincing evidence) and the standard required to find that but for the omission of a prior art reference, the PTO would have rejected a claim (preponderance of the evidence). Id. Because the Federal Circuit had affirmed the district court’s finding that the patents were invalid on § 103 obviousness grounds in part based on the withheld prior art references, it logically followed that such references were necessarily material to patentability. Id.

The court next applied the intent standard articulated in Therasense, which requires a showing “that the applicant knew of the reference, knew that it was material, and made a deliberate decision to withhold it.’” Id. (quoting Therasense, 469 F.3d at 1290). This specific intent to deceive must also be the “single most reasonable inference able to be drawn from the evidence.” Star Scientific, Inc. v. R.J. Reynolds Tobacco Co., 537 F.3d 1357, 1366 (Fed. Cir. 2008). The Federal Circuit agreed with the district court that Fabre’s argument—that he did not disclose the prior art because his experiments based on the prior art were failures—did not hold up because the Vidal reference disclosed the solution that he chose and Fabre only addressed experiments during direct examination that were failures and omitted others that were arguably not failures. Aventis Pharma, 2012 WL 1155716, at *8. The court similarly decided that Fabre’s defenses lacked credibility regarding the GV reference. Id. at *9.

The Federal Circuit’s decision reaffirms its holding in Therasense and sheds more light on the type of conduct from which it may infer an intent to deceive the PTO.

Laura Fishwick is a 2L at Harvard Law School