Pfizer wins Lipitor patent extension

Pfizer Inc fought off a US Supreme Court appeal that aimed to open the company's Lipitor cholesterol pill, the most widely prescribed drug in the world, to generic competition.

The high court, without comment, today turned away arguments from Indian drugmaker Ranbaxy Laboratories Ltd, which sought to block a patent extension that protects Lipitor in the US through March 2010.

A federal appeals court upheld the extension in August.

Lipitor, the top-selling drug in history, had sales of $12.9 billion last year and accounts for as much as 40 per cent of Pfizer's profit.

The New York-based company separately is asking federal patent examiners to re-issue a second patent that would prevent lower-priced generic competition until June 2011.

Ranbaxy argued unsuccessfully that Pfizer forfeited its right to an extension by failing to disclose important information to the US Patent and Trademark Office. Pfizer urged the Supreme Court not to hear the appeal.

Pfizer has lost patent protection on a succession of products including the epilepsy drug Neurontin, the antibiotic Zithromax and the anti-depressant Zoloft.

On March 22, a federal appeals court invalidated the drugmaker's patent on Norvasc, a hypertension drug.

Lipitor already faces competition from cheaper generic copies of Merck & Co.'s Zocor cholesterol-reducer, which lost patent protection in June. Pfizer is also trying to protect its Lipitor sales against newer, more potent cholesterol pills that are gaining market share, such as Merck and Schering-Plough Corp.'s Vytorin.

The patent at issue in the Supreme Court case originally was set to expire in May 2006. US government agencies extended the term to 2009 to compensate Pfizer for the time it spent to get Food and Drug Administration approval for Lipitor.

Pfizer got an additional extension of six months, to March 2010, because it planned to test the drug's effects on children.

Ranbaxy, based in the New Delhi suburb of Gurgaon, is India's largest drugmaker.