PTO turns down Pfizer request to reissue Lipitor patent

The Patent and Trademark Office sent a "nonfinal rejection" notice to Pfizer in response to its request for the agency to reissue a key Lipitor (atorvastatin) patent. The PTO noted that Ranbaxy had protested reissuance of the patent, contending that the patent claims were anticipated by prior art or were obvious. The agency agreed that some of the claims were anticipated or obvious but found that others were not. The U.S. Court of Appeals for the Federal Circuit ruled last year that a patent covering a Lipitor enantiomer was invalid due to technical defects in the patent. In January, Pfizer asked the PTO for permission to resubmit the patent to correct these defects. "It's common for the patent office to initially reject requests of this sort," a Pfizer spokesperson said. "We believe we have a strong argument" to address the concerns raised by PTO...