Sanofi-Aventis SA has taken its share of licks in its long-running battle with drug makers selling generic versions of Eloxatin, a drug used to treat colon cancer. Last year, in a Hatch-Waxman Act ruling, a New Jersey federal district court judge found that the generics did not infringe Sanofi’s patents. Then last month, the U.S. Food and Drug Administration approved the generic drugs for sale despite an appellate ruling granting Sanofi a stay of the district court order. But Sanofi finally got some good news on Thursday when the U.S. Court of Appeals for the Federal Circuit vacated the lower court’s ruling and remanded the case.

In 2007, Sanofi filed an infringement suit against Sandoz Inc., and nine other companies that had filed applications to sell generic versions of drugs containing oxaliplatin, the active ingredient in Eloxatin. The filing triggered an automatic 30-month stay on FDA approval of the generics. But in June 2008, Trenton, N.J., federal district court judge Joel Pisano granted summary judgment to the defendants, holding that Sanofi’s patent for oxaliplatin was limited to a process that the generic makers did not employ. Sanofi immediately appealed, and the Federal Circuit stayed Pisano’s order in July 2009.

In Thursday’s ruling, the three-judge panel of the Federal Circuit faulted Pisano’s interpretation of the Sanofi patent, holding that it was not limited to the particular process it specified for producing oxaliplatin, but instead covered the composition of “optically pure” oxaliplatin itself. “The district court erred in construing composition claims as product-by-process claims,” wrote Judge Kimberly Moore.

While clearly a win for Sanofi, the decision comes too late to keep its generic rivals out of the market for the cancer drug: The defendants have been selling generic versions of Eloxatin ever since the FDA granted them approval in August. We called Sanofi’s lead lawyer — Dominic Conde of Fitzpatrick, Cella, Harper & Scinto — to ask how the company planned to pursue the case now, but he referred us to his client for comment. (“Sanofi-aventis is pleased with the court’s ruling and we are currently considering our next steps,” the company told us.) Sanofi’s lawyers indicated during oral arguments before the Federal Circuit that they may seek a permanent injunction against further sales of the generics from the district court.

The defendants were represented at the Federal Circuit by Schiff Hardin (for Sandoz Inc.); Winston & Strawn (for Mayne Pharma Ltd.); Goodwin Procter (for Teva Parenteral Medicines Inc. and Barr Laboratories Inc); and Rothwell, Figg, Ernst & Manbeck (for Fresenius Kabi Oncology PLC).

This article first appeared on The Am Law Litigation Daily blog on