Proxy Statement to Be Prepared for Shareholder Meeting on Merger

Genzyme Corporation (Nasdaq: GENZ) announced today that it has completed its tender offer to acquire shares of Bioenvision, Inc. (Nasdaq: BIVN) capital stock and that a proxy statement will now be prepared by Bioenvision for a shareholder meeting to occur before the end of the year.

Genzyme will purchase approximately 22 percent of the outstanding shares of Bioenvision common stock on an as-converted basis, including the 100 percent of outstanding shares of preferred stock that have already been tendered. Each share of preferred stock can be converted into approximately two shares of common stock, and also carries a separate class vote over any merger or business combination of Bioenvision and approval of the authorization of any additional shares of Bioenvision common stock, as well as other features.

“We are proceeding with the purchase of all the Bioenvision preferred shares, as well as the common shares tendered,” stated Mark J. Enyedy, president of Genzyme Oncology, a business unit of Genzyme Corporation. "At a minimum, we are committed to playing an active and constructive role as a significant long-term shareholder of Bioenvision.”

Consistent with the merger agreement reached between Genzyme and Bioenvision on May 29, 2007, Bioenvision will now prepare a proxy statement to be mailed to its shareholders detailing the rationale for the merger and other material disclosures. This process is expected to culminate with a merger vote before the end of the year.

Genzyme agreed on May 29, 2007 to acquire Bioenvision in an all-cash transaction valued at $5.60 per outstanding common share and $11.20 per outstanding preferred share (plus accrued but unpaid dividends), or approximately $345 million.