Treatment Frequency Reduction in Pompe Disease

Inclusion Criteria: * LOPD (confirmed diagnosis: enzyme deficiency in any tissue source and/or 2 confirmed disease-causing variants in the GAA gene) * Age ≥50 years * Current treatment with alglucosidase alfa at a standard dose of 20 mg/kg once every 2 weeks for ≥4 years * Relatively stable clinical condition over the past year * Able to walk ≥150 m within 6 minutes (6MWT) * (Forced) vital capacity (FVC) in sitting position: \>55% of expected value and in supine position: \>45% of expected value * Willing and able to adhere to the study procedures Exclusion Criteria: * Rapidly progressive muscle weakness * Severely limited muscle strength almost requiring/requiring daily wheelchair use * Requiring respiratory support (non-invasive/invasive ventilation) or being at high risk to require respiratory support (ventilation) due to further deterioration of current pulmonary function. Using continuous positive airway pressure (CPAP) support only for obstructive sleep apnea syndrome (OSAS) is permitted. * Comorbidities which are expected to influence the primary outcome measures within the next 2 years