The United Kingdom's High Court has upheld the exclusivity of the main patent covering Pfizer's atorvastatin, the active ingredient in Lipitor, until November 2011.

The ruling is the result of a lawsuit brought by the generic manufacturer Ranbaxy Ltd., which challenged two patents protecting Lipitor. The court ruled that a Ranbaxy generic would infringe on Pfizer's basic Lipitor patent (EP 247,633). If upheld on appeal, this will prohibit Ranbaxy from introducing a generic version of atorvastatin in the United Kingdom before the expiration of that patent in November 2011.

The court ruled that a second patent covering the calcium salt of atorvastatin (EP 409,281) is invalid. Arrow Generics Ltd. joined Ranbaxy in the lawsuit on this patent. Pfizer said that it would appeal the decision on this patent, which expires in July 2010, according to a company release.

"This is an important victory not only for Pfizer but for all innovators pursuing high-risk medical discoveries that benefit current and future generations of patients around the world," said Pfizer chairman and chief executive officer Hank McKinnell.

"Lipitor is one of the most important medical breakthroughs of our era, and millions of patients have used it to lower their cholesterol. Recently, Lipitor has been approved in the United States to reduce the risk of stroke and heart attacks in a broad range of patients," McKinnell said. "This court decision is consistent with the fundamental principle that patent laws exist to support and encourage medical innovators, not undermine them," he added.

Since Lipitor was introduced in the United States in 1997, it has become the world's most prescribed cholesterol-lowering therapy. More than 18 million people in the United States have been prescribed Lipitor for lowering their cholesterol, and it is approved in more than 70 countries. Clinical research has also shown that Lipitor provides unique benefits that go beyond LDL cholesterol reduction, such as reducing cardiovascular events and halting the progression of atherosclerosis, or hardening of the arteries. Most recently, the US Food and Drug Administration approved a new indication for Lipitor for the millions of people who suffer from diabetes, added the release.