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An Inventor’s Lack of Credibility Can Lead to a Conclusion of Intent to Deceive and a Finding of Inequitable Conduct

April 09, 2012

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Last Month at the Federal Circuit - May 2012

Judges: Linn, Dyk, Prost (author)

[Appealed from: D. Del., Chief Judge Sleet]

In Aventis Pharma S.A. v. Hospira, Inc., No. 11-1018 (Fed. Cir. Apr. 9, 2012), the Federal Circuit affirmed the district court’s determinations that (1) the asserted claim from one of the two patents-in-suit was obvious and noninfringed; (2) the asserted claim from the other patent-in-suit was infringed but obvious; and (3) both of the patents-in-suit were unenforceable for inequitable conduct.

The two patents-in-suit, U.S. Patent Nos. 5,750,561 (“the ’561 patent”) and 5,714,512 (“the ’512 patent”), relate to the administration of the chemotherapy cancer drug docetaxel, which is marketed as Taxotere. Docetaxel belongs to a class of compounds known as taxanes, which are administered intravenously by delivering the drug in a diluted aqueous solution called a “perfusion.” Because taxanes have low solubility in water and tend to precipitate out of solution, they are mixed with additives like surfactants and ethanol to stabilize the solution and delay precipitation. The taxane and additives are mixed to form a stock solution, which is then mixed with an injectable solution to form the perfusion.

The surfactant Cremophor was used in the prior art to form taxane stock solutions, but was known to trigger allergic reactions, including anaphylactic shock. The ’561 and ’512 patents relate to using surfactants, other than Cremophor, with docetaxel and decreasing the amount of ethanol to reduce alcohol intoxication and anaphylactic effects.

Only claim 5 of the ’561 patent and claim 7 of the ’512 patent were at issue on appeal. Claim 5 of the ’561 patent is directed to a perfusion comprising docetaxel and the surfactant polysorbate, and recites that the “perfusion is capable of being injected without anaphylactic or alcohol intoxication manifestations being associated therewith.” Claim 7 of the ’512 patent is directed to a composition comprising docetaxel and polysorbate, and recites that the composition is “essentially free or free of ethanol.”

After Hospira, Inc. (“Hospira”) and Apotex Inc. and Apotex Corp. (collectively “Apotex”) applied to the FDA for approval to market generic versions of Taxotere, Aventis Pharma S.A. and Sanofi-Aventis U.S., L.L.C. (collectively “Sanofi”) sued for infringement of the ’561 and ’512 patents. After a bench trial, the district court found claim 7 of the ’512 patent obvious and not infringed, and claim 5 of the ’561 patent infringed but obvious. The district court also determined that the ’512 and ’561 patents were unenforceable for inequitable conduct, finding that the Vidal Dictionnaire (“Vidal”) and Guéritte-Voegelein (“GV”) references were material to patentability and that inventor Jean-Louis Fabre intentionally withheld them with the intent to deceive the PTO.

With respect to claim 5 of the ’561 patent, Sanofi argued that the district court erred in construing the term “perfusion” as “an injectable solution containing the active pharmaceutical ingredient and an aqueous infusion fluid.” Slip op. at 6 (citation omitted). According to Sanofi, the construction should have also required that the perfusion be effective for treatment, safe, and stable for at least eight hours.

On appeal, the Court dismissed Sanofi’s argument that the construction for “perfusion” should have required that it be effective for treatment, safe, and stable for at least eight hours. The Court explained that neither the claims, the specification, nor the prosecution history suggested that the claimed perfusion must satisfy certain safety or efficacy standards. With respect to the eight-hour stability limitation, the Court reiterated that narrowing a claim term beyond its plain and ordinary meaning was permissible only when a patentee acts as its own lexicographer, or when the patentee disavows the full scope of a claim term either in the specification or during prosecution. The Court explained that claim 5 contained no limitations with respect to the claimed perfusion’s stability. Acknowledging that the specification did include embodiments in which the perfusions had stabilities of about eight hours or more, the Court explained that those general descriptions of the characteristics of the embodiments were not sufficient to limit the claims, even if all of the embodiments were to contain a particular limitation.

Finally, the Court noted that statements made by the patentee during prosecution neither indicated that “perfusion” had a special definition nor clearly and unmistakably manifested the patentee’s intention to limit claim 5 to perfusions that were stable for at least eight hours.

Regarding the finding that claim 5 was obvious in light of the prior art (the GV and Vidal references), the Federal Circuit affirmed the district court’s determination because, during oral argument, Sanofi’s counsel confirmed that under the district court’s construction of “perfusion,” Sanofi did not dispute the obviousness finding.

Claim 7 of the ’512 patent claims a “composition,” which can be either a stock solution or a perfusion. With respect to stock solutions, the parties had agreed that the phrase “essentially free or free of ethanol” in claim 7 means “no more than 5% ethanol by volume.” Relying on that construction, the district court found that claim 7 was obvious in light of a prior art patent, which disclosed both ethanol-containing and essentially ethanol-free stock solutions. Because Sanofi did not address the district court’s obviousness finding with respect to stock solutions in its opening brief, the Federal Circuit considered the issue waived, even if the issue was addressed in Sanofi’s reply brief. Thus, because the district court’s obviousness finding regarding stock solutions was unchallenged, the Federal Circuit affirmed the obviousness determination of claim 7 of the ’512 patent.

Regarding inequitable conduct, the Court initially noted that “although the district court did not have the benefit of our Therasense opinion . . . , the court nevertheless found that the withheld references were but-for material to patentability and made distinct intent and materiality findings . . . , [and] we conclude that the court’s inequitable conduct determination withstands even the more rigorous standard adopted in Therasense.” Id. at 15.

With respect to the materiality prong, the Court indicated that a prior art reference “is but-for material if the PTO would not have allowed a claim had it been aware of the undisclosed prior art.” Id. at 16 (quoting Therasense, Inc. v. Becton, Dickinson & Co., 649 F.3d 1276, 1291 (Fed. Cir. 2011)). Here, the Court affirmed the district court’s finding that the ’561 and ’512 patents were invalid based on, inter alia, the withheld GV and Vidal references. Thus, the Court found that such references were necessarily material to patentability.

Citing the Therasense decision, the Federal Circuit indicated that, “[t]o satisfy the intent requirement, ‘the accused infringer must prove 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,’” and that “the specific intent to deceive must be ‘the single most reasonable inference able to be drawn from the evidence.’” Id. at 16-17 (quoting Therasense, 649 F.3d at 1292).

During trial, Fabre testified that he did not cite the Vidal reference because the experiments disclosed in the reference resulted in perfusions that were not stable for eight hours and were considered failures. Regarding the intent prong, Sanofi argued that, based on that testimony, the district court erred in finding Fabre had the specific intent to deceive because that finding was not the single most reasonable inference that could be drawn. The Court, however, gave deference to the determinations made by the district court, which found that Fabre’s testimony lacked credibility.

The Court also pointed out the district court’s emphasis on Fabre having disclosed a reference to the PTO identifying the problem Fabre’s invention was addressing, but then not citing the Vidal reference that contained the solution Fabre followed to solve the problem. Another inconsistency in Fabre’s testimony highlighted by the Court was that, on direct examination at trial, he discussed only those experiments prompted by the Vidal reference that were alleged failures, but then admitted under cross-examination that some experiments displayed stabilities of over thirty hours.

The Court reached the same conclusion regarding intent to deceive with respect to Sanofi’s GV reference. The GV reference disclosed a specific solution of docetaxel in a polysorbate 80/ethanol system. Fabre testified that he did not disclose the GV reference to the PTO because he only read an earlier draft that did not contain the reference to the polysorbate 80/docetaxel formulation. The Federal Circuit noted that the district court found that testimony not credible based on other evidence presented at trial.

The Federal Circuit concluded that the district court’s inequitable conduct determination was not an abuse of discretion because the district court’s thorough discussion of its factual findings and its well-reasoned analysis were consistent with Therasense. Accordingly, the Federal Circuit affirmed.

Summary authored by Carlos M. Tellez, Ph.D., Esq.