Enzyme Replacement Therapy in Patients Who Have Mucopolysaccharidosis I and Are Younger Than 5 Years: Results of a Multinational Study of Recombinant Human α-<scp>l</scp>-Iduronidase (Laronidase)

Laronidase seems to be well tolerated and to provide clinical benefit in patients who have severe mucopolysaccharidosis I and are <5 years old. Enzyme replacement therapy is not curative and may not improve all affected organs and systems in individuals when irreversible changes have developed. The long-term clinical outcome and effects of antibodies and laronidase dosing on glycosaminoglycan reduction warrant additional investigation.