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Genzyme Begins Enrolling Patients in Pivotal Pompe Disease Study

Posted on: May 29, 2003

Genzyme General (Nasdaq: GENZ), a division of Genzyme Corp., announced today that it has treated the first patient in a pivotal clinical trial evaluating the use of its MyozymeTM recombinant human acid alpha-glucosidase enzyme (rhGAA) as a potential treatment for Pompe disease. The trial, study 1602, is the second clinical trial that Genzyme initiated with this treatment this year, and will include up to 16 infants younger than six months of age at the time of their first infusion. Genzyme began enrollment in March of a clinical trial of Myozyme (study 1702) focused on children between the ages of six months and three years.

Genzyme expects to complete enrollment in both studies this year and to apply for marketing approvals for Myozyme in 2004 based on results from these trials, and on previous studies of enzyme replacement therapy for Pompe disease.

Both studies involve patients with the infantile-onset form of Pompe disease, in which symptoms manifest themselves during the first year of life. The 1602 trial announced today will examine the effect that Myozyme has at different doses on patient survival and on clinical factors such as respiratory function, and cardiac and muscle function. Infants with the most severe form of Pompe disease rarely survive more than one year without treatment. By contrast, the patients enrolled in the 1702 study announced in March span a broader range of symptoms and severity. Genzyme intends to use the results of these two trials to support global product registrations of Myozyme.

“The start of this clinical trial marks another important step toward the development of a safe and effective treatment for children with this devastating disorder,” said Richard Moscicki, MD, Genzyme’s chief medical officer and senior vice president of medical, clinical, and regulatory affairs. “We are enormously conscious that for these children, time is of the essence. We are continuing to work diligently with our clinical investigators and regulatory authorities to bring this important therapy to patients as quickly as possible.”

Both studies initiated this year are multi-center, international trials involving treatment sites in the United States and Europe. The 1602 study will also include a treatment site in Taiwan, where the disease is more prevalent.

About Pompe Disease

Pompe disease is a rare and sometimes fatal muscle disease caused by an inherited deficiency of the enzyme acid alpha-glucosidase (GAA), which is responsible for breaking down glycogen within specialized compartments called lysosomes in cells. Pompe disease ranges from a rapidly fatal infantile-onset form with severe cardiac involvement to a more slowly progressive late-onset form primarily affecting skeletal muscle. There is currently no therapeutic treatment available for the disease, which affects an estimated several thousand people worldwide.

Genzyme General develops and markets therapeutic products and diagnostic products and services. Genzyme General has six therapeutic products on the market and a strong pipeline of therapeutic products in development focused on the treatment of genetic diseases and other chronic debilitating disorders with well-defined patient populations. Genzyme General is a division of Genzyme Corp.

This press release contains forward-looking statements, including statements about: plans concerning clinical trials for a potential therapy for Pompe disease, including the anticipated timing and design of trials; estimates concerning the Pompe patient population; plans regarding submissions to regulatory authorities; and the potential future availability of a therapy for Pompe disease. These statements are subject to risks and uncertainties that could cause actual results to differ materially from those projected in these forward-looking statements. These risks and uncertainties include, among others: the receipt of IRB approvals for clinical trials and the timing thereof; enrollment rates for clinical trials; the actual efficacy and safety of rhGAA in humans and the actual timing of clinical trials; the results of pre-clinical and clinical studies; the actual timing and content of submissions to and decisions made by regulatory authorities concerning the Pompe product candidate and facilities, including the nature and extent of data required for marketing applications; the results and timing of qualifying runs at facilities; the ability to manufacture sufficient quantities of product for development activities (including without limitation extension studies and expanded access arrangements) and to do so in a timely and cost-efficient manner; the accuracy of Genzyme’s information concerning the Pompe patient population; and the risks and uncertainties described in reports filed by Genzyme with the Securities and Exchange Commission under the Securities Exchange Act of 1934, as amended, including without limitation Exhibit 99.2 to Genzyme’s 2002 Annual Report on Form 10-K, as amended. Genzyme General Division common stock is a series of common stock of Genzyme Corporation. Therefore, holders of Genzyme General Division common stock are subject to all of the risks and uncertainties described in the those reports. We caution investors not to place undue reliance on the forward-looking statements contained in this press release. These statements speak only as of the date of this press release, and we undertake no obligation to update or revise the statements. `

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