Pompe Program Update
March 2, 2009
Supply Update
In January 2009, Genzyme notified the Pompe community that we were experiencing a temporary constraint in
the global supply of Myozyme®
(alglucosidase alfa) produced at the 2000 L bioreactor scale and that
inventories were extremely tight. We are pleased to inform you that the European Commission has approved
the larger 4000 L scale production of Myozyme at Genzyme’s manufacturing facility in Belgium for use within
the European Union. With this approval, the demand on the 2000 L inventories that currently supply the rest of
the world, including MTAP in the US, has been relieved and the supply constraint is now resolved. The largerscale
Belgium facility will be able to help meet the long-term needs of patients for Myozyme upon receipt of
approval by regulatory agencies throughout the world.
Furthermore, as a result of this approval in Europe, the guidance issued to conserve Myozyme for infants and
children is no longer in effect and all adult patients worldwide can immediately resume regular infusion
schedules and physicians outside of the United States (US) are now able to initiate therapy for new adult
patients. In addition, due to the high degree of participation throughout the world of adult patients who
transitioned to monthly infusions in January and February, we would like to inform the community that
Genzyme has not been made aware of any infants or children who missed infusions during this period.
Please know that we at Genzyme deeply appreciate your support, engagement, and understanding in
managing through this temporary global supply constraint.
FDA Decision on Lumizyme™ (alglucosidase alfa)

There is also an important update regarding our application for alglucosidase alfa produced at the
2000 L scale in the United States, which will be known as Lumizyme. The FDA was unable to
approve Lumizyme on February 28th and has outlined, in a complete response letter we received on
February 27th, the items that need to be addressed before approval can be granted. Genzyme and
the agency had made substantial progress toward finalizing these items but were not able to
complete them before the action date. Specifically, Genzyme and the FDA must agree on a final
design for a verification study to confirm the clinical benefit of alglucosidase alfa produced at the
2000 L scale and on the details of a Risk Evaluation and Mitigation Strategy (REMS) for the product.
Genzyme must also address some issues detailed in a separate warning letter that was also
received on February 27th and related to observations made by the FDA during an inspection of our
Allston Landing, Massachusetts manufacturing facility before approval can be granted. We are
confident that all of the information can quickly be assembled and provided to the FDA. We will be
communicating with the FDA this week to start resolving the outstanding issues and will submit a
response as soon as possible.

Adult patients in the US currently enrolled in MTAP can continue to receive treatment via this access program
and should return to regular bi-weekly infusion schedules now that the supply constraint on the 2000 L product
has been resolved. Due to the supply capacity limitations of Myozyme produced at the 160 L scale, Myozyme
in the US will continue to be commercially available only to patients 17 years of age and younger. Upon
approval of Lumizyme in the US, it is anticipated that new adult patients with late-onset Pompe disease will be
able to access product through regular commercial channels; however, at this time, enrollment in MTAP
remains closed to new adult patients.

Although we are disappointed by this additional delay in the approval process, Genzyme now has
further clarity from the FDA on which issues remain outstanding. Our commitment to finding a
sustainable long-term solution for all those in need of therapy remains unchanged and we appreciate
the support and understanding the US community has demonstrated during this lengthy process.
We will continue to provide updates to the community as information becomes available.