Genzyme Ends Enrollment in Phase 2 Trial of Cardiac Cell Therapy

February 23, 2006, Genzyme Corporation (Nasdaq: GENZ) announced today that it has ceased to enroll new patients in its Phase 2 cardiac cell therapy trial. The trial’s Data Monitoring Committee (DMC), following a planned review of preliminary safety and efficacy data, recommended this step after concluding that there is a low likelihood that the trial would result in the hypothesized improvements in heart function, and that the study hypothesis has been adequately tested.

“Based on the preliminary results observed to date, we concur with the DMC that it is unlikely this trial will achieve success,” said Richard Moscicki, MD, chief medical officer for Genzyme. “Given this likely outcome, and the risks inherent in any clinical trial, we concluded that the most prudent action is to stop any new enrollment in the trial. We will continue to follow all 95 patients who have been enrolled to date, and will collect all data specified in the protocol throughout the follow-up period.”

Genzyme and the trial’s Steering Committee will conduct a thorough analysis of all efficacy and safety data from the trial at its completion, and will present the results when this analysis is complete.

About the Trial

The Myoblast Autologous Graft in Ischemic Cardiomyopathy (MAGIC) trial was designed to test whether autologous skeletal myoblasts can be used to reverse damage done to cardiac muscle following a heart attack, or to safely halt a patient’s further progression of heart failure. Heart failure is a usually incurable condition affecting more than 20 million individuals worldwide.

Patients who participated in the study had ischemic heart failure. A previous blockage in one of their coronary arteries caused a heart attack, creating a serious defect in the wall of their left ventricle. Patients were also diagnosed with an additional blockage in a coronary artery requiring coronary artery bypass grafting (CABG) surgery. In the study, one of two doses of autologous skeletal myoblasts or placebo were injected during CABG surgery in and around the scar tissue caused by the heart attack to attempt to strengthen the defect in the ventricular wall.

The trial was conducted with partial funding from Assistance Publique - Hôpitaux de Paris. Patients were enrolled at sites in France, United Kingdom, Italy, Belgium and Germany.

About Genzyme

One of the world’s leading biotechnology companies, Genzyme is dedicated to making a major positive impact on the lives of people with serious diseases. This year marks the 25th anniversary of Genzyme’s founding. Since 1981, the company has grown from a small start-up to a diversified enterprise with more than 8,000 employees in locations spanning the globe and 2005 revenues of $2.7 billion. Genzyme has been selected by FORTUNE as one of the “100 Best Companies to Work for” in the United States.

With many established products and services helping patients in more than 80 countries, Genzyme is a leader in the effort to develop and apply the most advanced technologies in the life sciences. The company’s products and services are focused on rare inherited disorders, kidney disease, orthopaedics, cancer, transplant and immune diseases, and diagnostic testing. Genzyme’s commitment to innovation continues today with a substantial development program focused on these fields, as well as heart disease and other areas of unmet medical need.

Contact Information

Dan Quinn

Media Contact

Genzyme Corporation

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