Winston & Strawn Knocks Out Sanofi Cancer Drug Patents for Hospira at Federal Circuit

This story originally appeared in our sister publication, The National Law Journal.

The U.S. Court of Appeals for the Federal Circuit has invalidated the patent on a cancer drug owned by Aventis Pharma S.A. and Sanofi-Aventis U.S. LLC. In so doing, the appeals court affirmed a finding of inequitable conduct, applying for the first time the tougher standard of proof it announced last May.

On April 9, a unanimous panel upheld a finding by Wilmington, Del., federal district court judge Gregory Sleet that two patents owned by Sanofi are unenforceable because of inequitable conduct, i.e., fraud on the U.S. Patent and Trademark Office.

In its 21-page ruling, the Federal Circuit applied the tougher standard it established in its May 2011 en banc ruling in Therasense Inc. v. Becton, Dickinson and Co.: “To prevail on an inequitable conduct defense, a defendant must establish both the materiality of the withheld reference and the applicant’s intent to deceive the PTO.” The appeals court found that even though the district judge made his inequitable conduct determination before Therasense was issued, that determination “withstands even the more rigorous standard adopted in Therasense.”

In addition, the court upheld Judge Sleet’s judgment that one claim in each of the patents was invalid for obviousness.

The two patents in the case are related to the administration of the chemotherapy cancer drug docetaxel, which has the brand name Taxotere. They are assigned to Sanofi.

Sanofi sued Hospira and Apotex Inc. after they applied for U.S. Food and Drug Administration approval to sell generic versions of the drug.

After deposing the inventor of the patents, Hospira included an inequitable conduct claim in its counterclaims. Hospira alleged that the inventor did not disclose two pieces of prior art–published information about the subject matter of the claimed invention, including issued patents–to the patent office. Apotex also added inequitable conduct to its counterclaims.

Judge Sleet issued his determinations of obviousness and inequitable conduct in September 2010.

Judge Sharon Prost wrote the Federal Circuit opinion, joined by judges Timothy Dyk and Richard Linn.

Prost observed, “In this case, although the district court did not have the benefit of our Therasense opinion when it rendered its inequitable conduct decision, the court nevertheless found that the withheld references were but-for material to patentability and made distinct intent and materiality findings rather than employing the now-abrogated sliding scale approach.”

With regard to materiality, Prost noted 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.’. . .Here, we have affirmed the district court’s finding that the [two] patents were invalid based on, inter alia, [two] withheld references.”

The Federal Circuit also agreed with the district court’s finding of intent. Prost observed, “In light of the evidence before the district court supporting the finding of a specific intent to deceive, coupled with the deference we must afford to the district court’s credibility determinations, we cannot conclude that the court’s finding that [named inventor Jean-Louis] Fabre withheld the [a key] reference with the specific intent to deceive the PTO was clearly erroneous.”

She concluded, “Based on the district court’s thorough discussion of its factual findings and its well-reasoned analysis that is consistent with Therasense, this determination was not an abuse of discretion.”

The Aventis ruling is notable because it survived Therasense’s higher inequitable conduct threshold. In Therasense, Chief Judge Randall Rader wrote the majority opinion, joined by Linn and judges Pauline Newman, Alan Lourie, Kimberly Moore and Jimmie Reyna. Judge Kathleen O’Malley concurred in part and dissented in part.

Judge William Bryson’s dissent was joined by Prost, Dyk and Judge Arthur Gajarsa. The dissent found the majority’s ruing “contrary to the Supreme Court decisions that gave rise to the doctrine of inequitable conduct, to a long line of our own precedent, and to the principles of materiality that courts have applied in other contexts.”

Two of those Therasense dissenters–Prost and Dyk–ended up on the Aventis panel.

Sanofi’s lawyers at Washington’s Covington & Burling did not respond to requests for comment.

“Sanofi US is disappointed by the Court of Appeals decision regarding its patents for Taxotere,” said Sanofi spokeswoman Carrie Brown. “The company is currently evaluating its options and next steps.”

Jim Hurst, the intellectual property chair at Chicago’s Winston & Strawn, who argued for Hospira, referred questions to his client.

Hospira is “pleased with the court’s ruling,” said spokesman Dan Rosenberg. “Hospira is committed to continuing to provide U.S. cancer patients with high-quality, lower-cost alternatives to branded oncology products,” Rosenberg said.

Richard Ruzich, a Chicago partner at Philadelphia’s Duane Morris who argued for Apotex Inc., referred questions to the company. Elie Betito, Apotex’s director public & government affairs, said the company doesn’t comment on pending litigation.

The ruling in Aventis was unsurprising, given the obviousness holdings, said Andrew Dhuey, a solo practitioner in Berkeley, Calif., who isn’t involved in the case.

This type of situation doesn’t trigger the the en banc dissenters’ concerns, which involved cases in which it’s not clear that the but-for test of patentability is met, Dhuey said. “We’re really waiting for a tougher case where we don’t have such clarity on whether the omitted references were the difference on patentability.”