Patent office sends Pfizer “non-final” rejection letter for Lipitor

NEW YORK The U.S. Patent and Trademark Office has preliminarily rejected Pfizer’s request for the reissue of a patent for its Lipitor (atorvastatin) cholesterol drug that would preserve its U.S. market exclusivity until 2011, the Wall Street Journal reported.

The U.S. Court of Appeals for the Federal Circuit invalidated in 2006 one of two patents at issue in a legal fight with generic competitor Ranbaxy, which moved up Lipitor’s June 2011 patent expiration and maintaining it instead to March 2010.

Ranbaxy had taken its case to the Supreme Court after the Federal U.S. Circuit Court of Appeals denied the company’s request to rehear the decision. The Supreme Court refused a hearing, preserving the March 2010 date.

Pfizer applied to the patent office in January to have the 2011 patent reissued, and to correct a "technical defect" in the original patent. A reissue would extend Pfizer’s market exclusivity through June 2011.

A Pfizer spokesman told the Journal on Thursday that the company was awaiting a letter from the patent office explaining the decision. Because it’s not a final rejection, Pfizer still has an opportunity to persuade the patent office to reissue the patent.

"An initial rejection is not uncommon in reissue application proceedings," said Pfizer spokesman Bryant Haskins. "Once we receive the decision we’ll review it and respond appropriately to address any issues that were raised by the examiner."

Lipitor is the best-selling drug in the world, with $12.9 billion in sales last year. However, it has faced pressure not only from ongoing patent challenges worldwide, but also from competition from generic versions of other anti-cholesterol drugs.