Overview

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.
• The number of visits will be 30, including 29 site visits and 1 phone call follow-up visit.

Eligibility

Inclusion Criteria:

• Participant must be <18 years of age, at the time of signing the informed consent.
• Participants have documented onset of Pompe disease symptoms before 12 months of age (corrected for gestation if born before 40 weeks); and diagnosis of IOPD is confirmed by GAA enzyme deficiency from any tissue source and GAA gene pathogenic mutations.
• Participants must have documented cardiomyopathy at the time of diagnosis.
• Contraceptive use should be consistent with local regulations Participant's parent/legally authorized representative (LAR) must be capable of giving signed informed consent.

Exclusion Criteria: Participants are excluded from the study if any of the following criteria apply:

• Participants with major congenital abnormality that, in the opinion of the Investigator, would preclude participation in the study or potentially decrease survival.
• Participants with clinically significant organic disease (with the exception of symptoms relating to Pompe disease).
• Participants who have received an ERT other than alglucosidase alfa or avalglucosidase alfa, or any other treatment for Pompe disease, including gene therapy prior to the enrollment.
• Participants who have received alglucosidase alfa or avalglucosidase alfa less than 1 week prior to the first dose of avalglucosidase alfa given as IMP Participants who are anticipated to take prohibited therapy (ie, any other treatment for Pompe disease) during this study.
• Participants who have taken other investigational drugs (not Pompe disease specific) within 30 days or 5 elimination half-lives in blood of that drug before enrollment, whichever is longer, or are anticipated to take any other concurrent investigational treatments.
• Participants not suitable for participation, whatever the reason, as judged by the Investigator, including medical or clinical conditions, or participants potentially at risk of noncompliance to study procedures.