WASHINGTON — Sanofi-Aventis is buying specialty drugmaker Genzyme for $20.1 billion, the latest example of a beleaguered pharmaceutical company snapping up high-priced biotech drugs to offset dwindling sales of older medicines facing generic competition.
Sanofi, the world’s fourth-largest drugmaker, overcame Genzyme’s reluctance to a takeover by raising its previous offer to $74 a share and agreeing to make additional cash payments pending the success of several drugs.
Wednesday’s announcement comes after nearly nine months of back-and-forth between the two companies, with Sanofi-Aventis finally deciding Genzyme’s portfolio of rare-disease treatments was worth adding an extra $5 a share to its original $69-a-share offer.
Genzyme’s shares rose 80 cents, or 1 percent, to $75.10 Wednesday.
The combination seems odd at first: a huge French company best known for vaccines used by millions of patients each year buying a Cambridge, Mass.-based biotech company whose drugs are taken by only a handful of patients around the world.
But experts say the merger reflects the landscape of the pharmaceutical industry, as companies seek to replace older medications that have lost their patent protection.
