Sanofi-Aventis completes buyout of Genzyme

Sanofi-Aventis said Friday it has completed its $20.1 billion buyout of specialty drugmaker Genzyme Corp.

In February, Sanofi raised its buyout offer to $74 per share and agreed to make additional cash payments pending the success of several drugs. That move came about after nine months of reluctance from Genzyme to accept a prior $69 per share offer.

Sanofi, based in Paris, is best known for its vaccines. Meanwhile, Genzyme, based in Cambridge, Massachusetts, makes biotech drugs aimed at treating genetic diseases.

Genzyme's best-seller Cerezyme treats Gaucher disease, an enzyme disorder that can result in liver and neurological problems. Its second-best seller, Fabrazyme, treats an inherited disorder known as Fabry disease, which is caused by the buildup of a particular type of fat in the eyes, kidneys and nervous system.

The Sanofi offer followed a tumultuous period for Genzyme starting with a viral contamination issue with its products in June 2009. The company shut down its plant in Boston for three months, slowing production and cutting into revenue for its two key moneymakers. That debacle was followed five months later by a citation from federal inspectors that bits of debris were found in some of its injectable drugs.

Throughout the period, Genzyme started to restructure its staff and business. It sold a diagnostic products unit and named a new president of global manufacturing and corporate operations, along with a senior vice president of global product quality.

Sanofi's U.S. shares rose 31 cents to close at $36.46.