US drug giant Pfizer has won a battle in a Dutch court to protect its multi-billion-dollar cholesterol buster Lipitor, thereby effectively barring Indian drugmaker Ranbaxy Laboratories from launching its copycat version of the drug in the country until its key patent expires in November 2011.

The District Court of The Hague sided with Pfizer in the ongoing global wrangle between the firms, by ruling that the basic patent protecting Lipitor (atorvastatin) would be infringed by a generic formulation of the product.

But the court also found that a second patent held by Pfizer, which relates to a calcium salt of atorvastatin, is invalid. Although Pfizer said it intends to appeal the ruling, it noted that it shouldn’t make a difference to Lipitor’s primary protection anyway, as this second patent expires in July 2010.

“Todays’ decision is another affirmation of the strength of the intellectual property behind Lipitor,” commented Pfizer’s General Counsel Allen Waxman. “The court’s ruling reinforces the fundamental principle that patent laws exist to support and encourage medical innovators, not undermine them,” he added.

Ranbaxy remained relatively tight-lipped in response to the ruling, which is still subject to appeal, saying only that it is “evaluating this decision and will decide on its course of action shortly.”

Lipitor is the world’s number one drug, with annual sales comfortably overshooting the $12-billion mark at the last glance, and Ranbaxy is fighting hard to get a piece of the action and sell its copycat version around the globe.

The company is among those generic groups that adopt a high-risk, high-reward strategy in the sector, spending on litigation in the hope of winning first-to-market advantage for its generic products. But its hopes of winning early entry into the atorvastatin market must be waning, given Pfizer’s recent victories in the UK, Finland, Spain, Norway, Romania, Peru, the USA and now The Netherlands.