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CAMBRIDGE, Mass.--Genzyme General (Nasdaq: GENZ) said that pre-clinical data presented today demonstrate the early promise of a therapy for cardiovascular disease that would employ a patient's own transplanted heart cells to improve cardiac function.

The data were presented at the annual meeting of the American Association for Thoracic Surgery by Ren-Ke Li, M.D., Ph.D., a member of a research group at Toronto General Hospital led by Richard Weisel, M.D. The group began collaborating with Genzyme in January to develop cell-based therapies for cardiovascular disease.

There are currently no therapies for restoring function to irreversibly damaged heart tissue. The transplantation of heart cells into the scar tissue that forms following a heart attack may strengthen and restore function to damaged areas of the heart and thereby improve cardiac performance and quality of life. It may also prevent or delay heart failure.

"We found in a pre-clinical study that cell therapy can improve heart function after a myocardial infarction," said Dr. Li.

In the study conducted by Dr. Li and his colleagues, a myocardial infarction was created in each of 18 adult pigs. At the time of infarction, the researchers removed healthy cells from the ventricle region and placed those cells into culture, where they expanded for the next four weeks. The researchers then injected the cultured heart cells into the damaged region of the heart in 12 of the pigs. The remaining seven pigs that were studied received an injection of culture medium only.

Four weeks after transplantation, the researchers observed improved motion and thickening in the ventricle wall and improved blood flow in the damaged cardiac region in the transplanted group and no improvement in the control group. In addition, ejection fraction--a measure of cardiac function--increased in the transplant group but not in the control group. The pigs that received the cultured cells were also more active and gained more weight than the control pigs.

Dr. Li also discussed the development of an autologous bioengineered cardiac graft that he and his colleagues created. The graft consisted of juvenile rat cardiac cells seeded into a gelatin mesh. Bioengineered cardiac grafts are being studied for use in treating heart defects. Patients with congenital heart defects frequently require graft material for cardiac reconstruction. Currently available grafts lack growth potential, do not have the capacity to contract, and can lead to the formation of blood clots.

"While these are early-stage results, they represent important progress in our cardiovascular cell therapy program," said Earl M. Collier Jr., president of Genzyme Surgical Products. "We are moving forward aggressively with our cell transplantation pre-clinical development program and plan to initiate human clinical trials in early 2001."

Genzyme has significant expertise in cell therapy product development, manufacturing, and commercialization. This expertise has been gained through Genzyme Tissue Repair (Nasdaq: GZTR), which has two products on the market that use a patient's own cells to repair damaged tissue.

Cell therapy is one of a number of biotechnology-based approaches to treating cardiovascular disease that Genzyme Surgical Products is pursuing. Genzyme Surgical Products is also working with researchers at a number of institutions to develop gene therapy products intended to supplement established treatments for both ischemic heart disease and congestive heart failure. In addition, Genzyme Surgical Products intends to begin a clinical trial soon in cardiac surgery using Seprafilm(R) II Adhesion Barrier, its second-generation product designed to reduce the incidence and extent of post-surgical adhesions.

Genzyme General recently announced that Genzyme Corp. intends to create a separate division with its own series of common stock for Genzyme Surgical Products, which is currently a business unit of Genzyme General. Genzyme is creating the surgical products division to focus more resources and attention on building its "biosurgery" business. Biosurgery is the convergence of mechanical and biological approaches to surgery and interventional procedures. Genzyme is pioneering this field and intends to leverage both its franchise in medical devices and its diverse biotechnology platforms.

Genzyme General develops and markets therapeutic and surgical products and diagnostic products and services. A division of the biotechnology company Genzyme Corp., Genzyme General has its own common stock intended to reflect its value and track its economic performance.

This press release contains forward-looking information, including statements about the potential efficacy of cell transplantation as a therapy for cardiovascular disease in humans, the expected timing of clinical trials, and Genzyme's intention to create a separate surgical products division focused on the biosurgery market. Actual results may differ materially depending on a number of factors, including Genzyme's ability to demonstrate the safety and efficacy of cell transplantation as a therapy for cardiovascular disease, the results of pre-clinical and clinical development efforts, the enrollment rate for clinical trials, the timing and content of submissions to and decisions by the U.S. Food and Drug Administration and other regulatory authorities, the receipt of necessary corporate approvals for the creation of the new surgical products division, the results of Genzyme's business development efforts in the biosurgery market, and the competitive environment in the biosurgery mark

Genzyme's releases are available at http://www.genzyme.com and on the company's fax-on-demand service at 1-800-436-1443 in the U.S. or 1-201-521-1080 elsewhere.