Genzyme Provides Update on Allston Landing Plant

Genzyme Provides Update on Allston Landing Plant

Date: July 31, 2009

Genzyme Corporation (NASDAQ: GENZ) announced today that the FDA informed the company late Thursday that it will re-inspect the company's Allston Landing manufacturing facility. The re-inspection is a follow-up to an inspection the agency conducted in May 2009 and is intended to verify that all corrective and preventative actions identified in a February warning letter have been implemented.

In its letter to Genzyme yesterday, the agency indicated that all promised actions had not been either fully or adequately implemented at the time of the May inspection. Genzyme will work with the FDA to schedule the re-inspection as soon as possible.

During the re-inspection, the FDA will also review Genzyme's remediation efforts related to the recent identification of a virus at the Allston plant that required the company to temporarily halt production. The sanitization of the facility is complete and production of Fabrazyme® (agalsidase beta) and Cerezyme® (imiglucerase for injection) has resumed.

This press release contains forward-looking statements about Genzyme's business, including its expectation regarding the timing of the FDA re-inspection. These statements are subject to risks and uncertainties that could cause actual results to differ materially from those forecasted. These risks and uncertainties include, among others: that the FDA does not re-inspect the Allston facility in a timely manner; that the FDA identifies issues that cause a delay in Lumizyme approval or further constrain Cerezyme and Fabrazyme inventory; and the risks and uncertainties described in Genzyme's SEC reports filed under the Securities Exchange Act of 1934, including the factors discussed under the caption "Risk Factors" in Genzyme's Quarterly Report on Form 10-Q for the quarter ended March 31, 2009. Genzyme cautions investors not to place substantial reliance on the forward-looking statements contained in this press release. These statements speak only as of today's date and Genzyme undertakes no obligation to update or revise the statements.

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. Since 1981, the company has grown from a small start-up to a diversified enterprise with more than 11,000 employees in locations spanning the globe and 2008 revenues of $4.6 billion.

With many established products and services helping patients in approximately 100 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 disease, and diagnostic testing. Genzyme's commitment to innovation continues today with a substantial development program focused on these fields, as well as cardiovascular disease, neurodegenerative diseases, and other areas of unmet medical need.

Genzyme®, Cerezyme® and Fabrazyme® are registered trademarks, and LumizymeTM is a trademark, of Genzyme Corporation or its subsidiaries. All rights reserved.

Genzyme's press releases and other company information are available at www.genzyme.com and by calling Genzyme's investor information line at 1-800-905-4369 within the United States or 1-678-999-4572 outside the United Stat