Federal courts have ruled in Pfizer's favour in two recent challenges to the company's patents for Vantin and Zoloft, Pfizer said.

A decision by the Court of Appeals for the Federal Circuit upheld a preliminary injunction prohibiting Ranbaxy Pharmaceuticals, Inc. of India from marketing a generic version of Pfizer's Vantin antibiotic.

The court affirmed a lower court ruling by the US District Court of New Jersey and, in addition, decided in Pfizer's favour on a cross-appeal of the amount of bond the company is obligated to post in the case. The determination of bond was remanded to the district court with instructions to reduce the $15 million it had initially required.

Pfizer had filed a patent infringement suit and request for the preliminary injunction in November 2001. The injunction was granted in July 2003 but the district court has not yet set a trial date for the case. Pfizer's patent will expire in March 2004.

Two other pharmaceutical companies, Sankyo Company Limited and Takeda Chemical Industries, Ltd., also are plaintiffs in the suit. Pfizer legacy company Pharmacia has an exclusive sub-license to the patent from Sankyo. Sankyo is the exclusive licensee of Takeda, which holds the original patent for Vantin.

In a separate decision earlier this month, the US District Court of Massachusetts granted Pfizer's motion to dismiss a lawsuit by Teva Pharmaceuticals challenging Pfizer's patent for its antidepressant, Zoloft. Teva had claimed both non-infringement and invalidity of the patent for a specific form of sertraline. Sertraline is the active ingredient in Zoloft.