China Post-approval Commitment (PAC) Study of Avalglucosidase Alfa in Participants With IOPD

This is a single group, 52-week treatment, Phase 4, open-label, single-arm study to assess the safety and efficacy of avalglucosidase alfa IV infusion in male and female Chinese participants with IOPD who are treatment-naïve or were previously treated with ERT. Study details include: * The study duration: total study duration is approximately 64 weeks. * Screening period of up to 8 weeks * Treatment period of 52 weeks * Follow-up period of 4 weeks. (if the participant enrolls in another study or receives commercially available ERT, the follow-up period may be reduced from 4 to 2 weeks) * The number of visits will be 30, including 29 site visits and 1 phone call follow-up visit.