First treatment for rare enzyme disorder

FDA Consumer, July-August, 2003

The first treatment for people with certain forms of a rare genetic disease called MPS I has been approved by the FDA. MPS I occurs when a particular enzyme is absent or malfunctions in the body. The enzyme normally breaks down molecules called glycosaminoglycans (GAG) in the cells. People with MPS I have a buildup of GAG in the cells, resulting in progressive cellular damage that affects appearance, physical abilities, organ functions and, in some cases, mental development.

The new biotechnology product, Aldurazyme (laronidase), is a version of the deficient enzyme. Aldurazyme helps prevent the buildup of GAG in the cells and has been shown to improve lung function and exercise ability.

Aldurazyme is approved for people with the Hurler and Hurler-Scheie forms of MPS I as well as those with the Scheie form with moderate to severe symptoms. Hurler syndrome is the most severe of the MPS I forms. Children with Hurler syndrome often die early from respiratory diseases and cardiac complications. Hurler-Scheie syndrome is less severe, but people who have it usually do not survive beyond their early 20s. Scheie syndrome is the mildest form, with many patients living well into adulthood.

Studies in Canada indicate that 1 in 100,000 babies born has Hurler syndrome, 1 in 115,000 has Hurler-Scheie syndrome, and 1 in 500,000 has Scheie syndrome. Similar studies have not been done in the United States.

Aldurazyme is manufactured by BioMarin Pharmaceutical Inc. of Novato, Calif.