Study 701-901, a multicenter, multinational, longitudinal, non-interventional observational study in subjects, at least 18 years old, diagnosed with late-onset Pompe disease prospectively collects data to understand clinical progression in terms of respiratory function, symptomology, genotype, biochemistry, endurance and selected subject-reported measures for 24 weeks followed by a 240 week additional observation period for up to 100 subjects.

Inclusion Criteria:

• Willing and able to provide written informed consent after the nature of the study has been explained and prior to any study-related procedure
• Diagnosed with late-onset Pompe disease based on current or previous genomic testing and/or endogenous GAA activity
• At least 18 years of age at study entry
• Willing and able to comply with all study procedures

Exclusion Criteria:

• Requires non-invasive ventilatory support while awake and in the upright position
• Concurrent disease, medical condition, or extenuating circumstance that, in the opinion of the investigator, might compromise study completion or data collection
• Unable to perform baseline efficacy assessments

Late-onset Pompe Disease patients untreated or treated with rhGAA