Pfizer defends one Lipitor patent case, but loses second

US drug major Pfizer says that the US Appeals Court for the Federal Circuit has upheld its Lipitor (atorvastatin) patent, number 4,681,893. The decision, according to Pfizer, affords it US marketing exclusivity for the drug, which is the world's all-time best selling drug earning revenues in the region of $12.0 billion per year, until 2010. However in a second ruling, the CAFC also found that a second of Pfizer's Lipitor patents, also being contested by the Indian pharmaceutical firm Ranbaxy (number 5,273,995), was invalid on technical grounds, given that it was due to expire in June 2011. The ruling overturns an earlier Delaware District Court decision, and gives Ranbaxy the opportunity to bring forward the launch of its generic version of the drug to March 2010 with 180-day exclusivity in the US market. This is effectively the second patent challenge that Pfizer has faced in the last week (see also company column this page).