Pfizer Inc has announced that the Court of Appeals for the Federal Circuit has denied Ranbaxy's petition for rehearing of an August 2 decision upholding the exclusivity of the main patent covering atorvastatin, the active ingredient in Lipitor. That patent expires in March 2010.

"The court has declined to further review the August 2 decision," said Peter Richardson, Pfizer's senior vice president and associate general counsel. "As we noted in our response to the rehearing petition, the issues in this case were straightforward, the lower court's decision was consistent with prior law, and it raised no matters of exceptional importance requiring that they be revisited again."

Pfizer now plans to go back to the US Patent office to seek to correct a technical defect in a second patent covering the calcium salt of atorvastatin. The second patent, expiring in June 2011, was ruled invalid by the court on technical grounds.

The company noted that Ranbaxy may seek review of the court of appeals decision by the US Supreme Court.