Antibody formation to enzyme therapy in classic infantile Pompe disease: implications of patient age

Enzyme-replacement therapy (ERT) with alglucosidase alfa has improved the lifespan of patients with classic infantile Pompe disease, although ERT is not effective in a subset of patients who mount an immune response to the exogenous enzyme. We studied the development of antibodies in response to ERT and its effect on clinical outcomes in 11 patients with classic infantile Pompe disease treated with ERT since 1999 for a median of 4.2 years (range 3 months to 12 years).