Genzyme Transgenics Corporation has signed a letter of intent to re-acquire rights in Europe and the Americas from Genzyme Corporation for recombinant human antithrombin III (rhATIII), currently being studied under an Investigational New Drug Application. Within Genzyme Corporation, these rights have been allocated to Genzyme General. Terms and conditions are not disclosed pending a final agreement, which is expected around the end of the year.

"We believe that rhATIII is a promising therapeutic product candidate that will pave the way for other transgenic products," stated Henri A. Termeer, president and chief executive officer of Genzyme Corporation. "At this time, we are completing our proposed acquisition of GelTex Pharmaceuticals Inc, which will add a significant number of new product candidates into our already robust pipeline. In addition, we are directing Genzyme General's resources to an aggressive clinical development program for Renagel, to develop new therapies for other chronic debilitating diseases, and to continue to expand our franchise in enzyme replacement therapies."

"The re-acquisition of these rights will allow GTC to take the lead in developing this product worldwide," stated Sandra Nusinoff Lehrman, president and chief executive officer of GTC. "We believe that this therapeutic protein may offer advantages over plasma ATIII, including consistent and reliable supply, and the ability to economically increase production as new indications are identified, developed, and appropriate regulatory approvals are obtained. We thank Genzyme for providing early support to this product. GTC will continue to actively expand its alliances in its primary area of focus and main business driver, the development of monoclonal antibodies and immunoglobulin fusion proteins, with existing partners such as Centocor, Bristol-Myers Squibb, Abgenix, and Alexion."

GTC expects to aggressively develop rhATIII and to enhance the clinical development program. GTC is in active discussions with potential development partners for a variety of potential new indications. Anticipated changes in the clinical development plan will result in an expected 2002 filing of the Biologics License Application for rhATIII for use in managing heparin resistance during cardiopulmonary bypass surgery. GTC plans to augment the clinical studies with additional patient exposure data.