Sanofi Successfully Completes Exchange Offer for Genzyme

Sanofi-aventis has successfully completed its exchange offer for all outstanding shares of common stock of Genzyme Corporation.

Sanofi-aventis has successfully completed its exchange offer for all outstanding shares of common stock of Genzyme Corporation.The exchange offer and withdrawal rights expired at 11:59 p.m, New York City time, on April 1, 2011. The depositary for the exchange offer has advised sanofi-aventis that, as of the expiration time, 224,528,469 shares of Genzyme common stock (including 43,285,259 shares subject to guarantees of delivery) were validly tendered and not withdrawn.

To allow remaining Genzyme shareholders the opportunity to tender their shares, sanofi-aventis has also announced the opening of a subsequent offer period beginning on April 4, 2011, as contemplated by the merger agreement. The subsequent offer period will expire at 6:00 p.m., New York City time on Thursday, April 7, 2011.