NEW YORK, Nov. 29 (UPI) -- Pfizer said Tuesday that the U.S. Patent Office is upholding the validity of a patent on its cholesterol drug Lipitor.
The New York, N.Y.-based drug giant said that, following a legal challenge, PTO will confirm the validity of its patent covering Lipitor's active ingredient, a crystalline form of atorvastatin calcium.
Pfizer had argued that the crystalline formulation covered by the patent at issue was novel and was not described in the prior art, or previously developed technology.
The company noted that its latest Lipitor patent victory is not related to its ongoing litigation with generic drug firm Ranbaxy, involving the basic and enantiomer patents on Lipitor, effective through March 2010 and June 2011, respectively.
India-based Ranbaxy has its own cholesterol-lowering drug ready to launch and has been challengig the Lipitor patents worldwide with mixed success.
A British court earlier this fall ruled against Ranbaxy, upholding Lipitor's basic patent, while invalidating another patent on a specific aspect of the drug.
Similarly, Norwegian patent authorities found that Ranbaxy's process patent did not infringe Pfizer's patent, but also held that a Ranbaxy intermediate compound did infringe the Lipitor patent.
A decision on Ranbaxy's U.S. patent challenge could reportedly come by year's end.
Launched in 1997, Lipitor is the world's top-selling lipid-lowering therapy, Pfizer said.
