Exploratory Muscle Biopsy Assessment Study in Patients With Late-Onset Pompe Disease Treated With Alglucosidase Alfa

A Phase 4 Prospective Exploratory Muscle Biopsy, Biomarker, and Imaging Assessment Study in Patients With Late-Onset Pompe Disease Treated With Alglucosidase Alfa

This is an open-label, multicenter study of participants with late-onset Pompe disease naive to treatment with enzyme replacement therapy (ERT). The primary objective of this study is to evaluate glycogen clearance in muscle tissue samples collected pre and post alglucosidase alfa treatment in participants with Late-Onset Pompe disease.

The secondary objectives are to characterize the disease burden in participants with late-onset Pompe disease and explore imaging, histologic, and functional assessments in these participants and to explore potential plasma or urine biomarkers relative to late-onset Pompe disease and participant's response to treatment with alglucosidase alfa (Myozyme®/Lumizyme®/GZ419829).

Inclusion Criteria:

• The participant has confirmed acid alpha-glucosidase (GAA) enzyme deficiency from any tissue source and/or confirmed GAA gene mutations and without known cardiac hypertrophy
• The participant is able to ambulate a distance without stopping and without an assistive device. Use of assistive device for community ambulation is appropriate
• The participant has a certain forced vital capacity (FVC) in upright position
• The participant, if female and of childbearing potential, must have a negative pregnancy test (urine beta-human chorionic gonadotropin [beta-hCG]) at baseline

Exclusion Criteria:

• The participant has had previous treatment with ERT
• The participant is wheelchair dependent
• The participant requires invasive-ventilation (non-invasive ventilation is allowed)
• The participant is participating in another clinical study using investigational treatment
• The participant cannot submit to magnetic resonance imaging (MRI) examination because of a formal contraindication such as a pacemaker, implanted ferromagnetic metals, etc
• The participant, in the opinion of the Investigator, is unable to adhere to the requirements of the study