Kuperus E, et al. - This prospective study was conducted to ascertain the effect of enzyme replacement therapy (ERT) after 5 years and to identify predictors for a favorable response because few data were available on the long-term efficacy of ERT in Pompe disease. In adult patients with Pompe disease, long-term ERT positively influenced muscle strength, pulmonary function, and daily life activities, with a peak effect at ≈2 to 3 years of treatment.