Genzyme Temporarily Interrupts Production at Allston Plant

CAMBRIDGE, Mass.--(Business Wire)--
Genzyme Corporation (NASDAQ: GENZ) today announced that it has detected a virus
that impairs cell growth in one of six bioreactors at its Allston Landing
manufacturing facility. The company has decided to temporarily interrupt bulk
production at the plant to sanitize the facility. Genzyme is collaborating with
regulatory agencies as it works to resume production. The company expects the
plant to be fully operational by the end of July.

The virus strain, Vesivirus 2117, has not been shown to cause human infection.
It is known to interfere with the growth of CHO cells used to produce biologic
drugs and was likely introduced through a nutrient used in the manufacturing
process. Genzyme has now confirmed that this virus was the cause of declines in
cell productivity at its Allston and Geel facilities in two previous instances
in 2008, which were subsequently fully addressed. The company was able to detect
the virus in this case using a highly specific assay it developed after standard
tests were unable to identify the cause of the previous productivity declines.
Genzyme is adding steps to increase the robustness of its raw materials
screening and viral removal processes.

Current inventories for Cerezyme® (imiglucerase for injection) and Fabrazyme®
(agalsidase beta) are not sufficient to meet projected global demand. The timing
and extent of the Cerezyme supply constraint is being clarified and will be
communicated as soon as possible. The company expects Fabrazyme supply
constraints to occur for a limited period beginning in September. The company
will work with physicians, patients and regulators to minimize the impact of
this constraint.

"The patients who need these therapies are our priority," said Henri A. Termeer,
Genzyme`s chairman and chief executive officer. "We are confident in the quality
of the products produced in Allston and in our ability to resolve the issue
affecting the plant. The impact will be temporary."

Genzyme identified the virus at the Allston plant over the weekend. On Monday
morning, the company submitted information to the FDA and EMEA on its findings.
The company held a conference call with the FDA on Monday afternoon. With
regulatory input, Genzyme is finalizing its action plan and assessing the
business impact of this situation. The company will provide updated financial
guidance as soon as possible.

Conference Call Information

Genzyme will host a conference call today at 12:00 p.m. Eastern. To participate
in the call, please dial 773-799-3828 and refer to pass code "Genzyme." A replay
of this call will be available by dialing 402-220-2056 until June 23. This call
will also be Webcast live on the investor events section of www.genzyme.com.

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.

This press release contains forward-looking statements regarding Genzyme`s
business, including without limitation: its assessment of the impact of the
Vesivirus on the company, including the duration of the production interruption
at its Allston Landing manufacturing facility and the expected duration of the
Fabrazyme supply constraint. 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 Genzyme is
unable to resume production of Fabrazyme and Cerezyme by the end of July due to
its failure to sanitize the facility, concerns from regulatory authorities
regarding production at the facility, or any other reason; that the current
inventory in process at the facility cannot be released; 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.

Genzyme, Cerezyme and Fabrazyme are registered trademarks 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
States.

Genzyme Corporation
Media Contact:
Bo Piela, 617-768-6579
or
Investor Contact:
Patrick Flanigan, 617-768-6563

Copyright Business Wire 2009