Pfizer–Warner-Lambert (2000)
Pfizer paid $90 billion in stock for Warner-Lambert, primarily to take full control of Lipitor, the cholesterol drug they had been co-marketing. At the time it was the second-largest corporate merger in U.S. history.
Pfizer became the largest pharmaceutical company in the world and Lipitor went on to generate more than $125 billion in lifetime sales.
When Lipitor lost U.S. patent protection in 2011, Pfizer's revenue dropped sharply. The company has been buying its way back to growth ever since.
The Lipitor cycle is the template for the current wave: a single blockbuster carries a company for a decade, then patent expiration forces a buying spree to replace it. Merck is now in Pfizer's 2010 position with Keytruda.
