Genzyme Genetics Announces Availability of Molecular Testing for
Chronic Myeloid Leukemia Through Novartis CML ALLIANCE™

Date: July 31, 2007

WESTBOROUGH, MA -- Genzyme Genetics, a business unit of Genzyme Corporation, announced today that it will provide standardized molecular testing services as part of the CML ALLIANCE, a clinical support program developed by Novartis to help optimize treatment outcomes. The goal of this new monitoring system is to identify changes in patient response to chronic myeloid leukemia (CML) therapy and enable physicians to make treatment adjustments as early as possible.

The CML ALLIANCE builds on extensive experience in the treatment of CML, and offers the latest resources, including professional education, patient information and support, access to standardized molecular testing, access to reimbursement support services, and information on clinical trials with investigational agents and existing therapies in CML.

Through the CML ALLIANCE, Genzyme will offer a new Alliance RQ-PCR^SM test to monitor BCR-ABL transcript levels. A mutation known as BCR-ABL is the molecular hallmark of CML and is found in greater than 95 percent of patients with the disease. Using a graph included as part of Genzyme’s test report for the Alliance RQ-PCR, physicians and patients will be able to better understand visually how the patient is responding to treatment. This is important because RQ-PCR helps to precisely monitor patient responses to therapy and ensure that treatment is optimized over time.

“The CML ALLIANCE is an excellent example of the strides our industry is making towards personalized medicine by combining resources to help physicians select and monitor the appropriate therapies for their patients,“ said Mara Aspinall, president of Genzyme Genetics. “This collaboration with Novartis provides us with a great opportunity to standardize CML testing, and build awareness around the importance of continued monitoring in the management of cancer.” 

About CML

Chronic myeloid leukemia is also known as chronic myelogenous leukemia. According to the American Cancer Society, CML is a type of cancer that starts in blood-forming cells of the bone marrow and then invades the blood. It can spread to the lymph nodes, spleen, liver, and other parts of the body. CML can also change into a fast-growing acute leukemia that invades almost any organ in the body.

The American Cancer Society estimated that there were approximately 4,600 new cases of CML diagnosed in 2005. Approximately 25,000 CML patients are living in remission on therapy in the U.S. today. The average age of people with CML is around 50 years.

About Genzyme Genetics

Genzyme Genetics is a leading, nationwide provider of high quality genetic testing and genetic counseling services for physicians and their patients. With laboratories and counseling facilities located across the U.S., Genzyme Genetics offers extensive reproductive and cancer testing services, supported by innovative technology and a commitment to quality service and trusted information. Genzyme Genetics is a business unit of Genzyme Corporation.

About Genzyme Corporation

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. Since 1981, the company has grown from a small start-up to a diversified enterprise with more than 9,000 employees in locations spanning the globe and 2006 revenues of $3.2 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 nearly 90 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 diagnostic testing. Genzyme's commitment to innovation continues today with a substantial development program focused on these fields, as well as immune disease, infectious disease, and other areas of unmet medical need.

This press release contains forward-looking statements, including the statements regarding the ability of Genzyme to offer and to provide standardized molecular testing services as part of the CML Alliance, the ability of the monitoring system to identify changes in patient response and to enable physicians to make treatment adjustments as early as possible, and the ability of the test report to provide physicians and patients with a better visual understanding of the patient’s response to treatment. 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 failure of the Alliance RQ-PCR test to produce diagnostic results as anticipated, the inability of the Alliance RQ-PCR test to identify changes in patient response or enable physicians to make treatment adjustments as early as possible, the continued availability of Alliance RQ-PCR testing resulting from termination of the CML ALLIANCE relationship or the lack of commercial acceptance of this test, including the acceptance of the test at price levels that are economically viable for Genzyme Genetics, the extent to which a better visual understanding of the patient’s response to treatment is achieved based upon Genzyme’s test report, 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 the information under the heading "Risk Factors" in the Management's Discussion and Analysis of Financial Condition and Results of Operations section of the Genzyme Quarterly Report on Form 10-Q for the quarter ending March 31, 2007. Genzyme cautions investors not to place substantial reliance on the forward-looking statements contained in this press release. These statements speak only as of the date of this press release, and Genzyme undertakes no obligation to update or revise the statements.

Genzyme^® is a registered trademark of Genzyme Corporation. CML ALLIANCE™ is a service mark of Novartis AG. Alliance RQ-PCR ^SM is a service mark of Genzyme Corporation. All rights reserved.

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