From wikipedia:
In 1996, Warner-Lambert entered into a co-marketing agreement with Pfizer to sell Lipitor, and in 2000, Pfizer acquired Warner-Lambert for $90.2 billion.[62][57][58][59] Lipitor was on the market by 1996.[60][63] By 2003, Lipitor had become the best selling pharmaceutical in the United States.[55] From 1996 to 2012, under the trade name Lipitor, atorvastatin became the world's best-selling medication of all time, with more than $125 billion in sales over approximately 14.5 years.[64] Lipitor alone "provided up to a quarter of Pfizer Inc.'s annual revenue for years."[64]
Pfizer's patent on atorvastatin expired in November 2011.
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