Pfizer's Lipitor patent rejected

NEW YORK U.S. patent officials have rejected claims for the basic patent on Pfizer’s cholesterol drug Lipitor, according to Reuters. This rejection though is only the first step and Pfizer believes that ultimately the patent will be upheld.

The patent meanwhile will stay in effect while the officials re-examine it, a process that according to Pfizer could take as long as a few years to accomplish. This patent originally was suppose to expire in March 2010.

In July, Ranbaxy Laboratories requested a re-examination of the patent. The drug has annual sales of about $12 billion worldwide, making it the world’s biggest-selling drug.

An initial rejection is not unusual, and Pfizer will follow with a response in the next two months, the company said. Pfizer also wants U.S. officials to reissue a second Lipitor patent, which could extend its hold on the drug until June 2011.