Primary Objective:

To evaluate effect of 52-week treatment with Alglucosidase Alfa in the extension of survival and improvement of cardiomyopathy measured by Left Ventricular Mass Index in Chinese patients with infantile-onset Pompe Disease.

Secondary Objectives:

• To observe the improvement of physical growth, motor and cognitive development of 52-week treatment with Alglucosidase Alfa in infantile-onset Pompe Disease from the baseline.
• To observe the efficacy on survival free of invasive ventilation, use of any ventilation support of 52- week treatment with Alglucosidase Alfa in Chinese patients with infantile-onset Pompe Disease.
• To evaluate the safety and tolerability of Alglucosidase Alfa in Chinese patients with infantile-onset Pompe Disease.

Total of 56 weeks in the study period, including an up to 28-day screening period and 52-week treatment period, followed by 30-day post-treatment observation period.

After the end of 52-week treatment, patients' guardians could choose to participate in a patient assistance program (PAP) sponsored by Sanofi and launched before first patient out (FPO) or reimbursement from social insurance for continued treatment.

Inclusion criteria:

• Subject's parents or legal guardians must provide written informed consent prior to any study-related procedures.
• Documented onset of Pompe disease symptoms up to 12 months of age (corrected for gestation if born before 40 weeks); diagnosis of Pompe disease confirmed by acid alpha-glucosidase enzyme deficiency from any tissue source and acid alpha-glucosidase gene mutations.
• Age 0-12 months at enrollment, defined as at the time of providing written informed consent.
• Cardiomyopathy (abnormal left ventricular mass indices [LVMIs], measured by echocardiography, abnormal value is defined as ≥65 g/m2 for patients up to 12 months old) confirmed by cardiologist at study site.

Exclusion criteria:

• Patient who has previously been treated with acid alpha-glucosidase.
• Patient who is participating in another clinical study using any investigational therapy.
• Conditions/situations such as:
• Clinical signs of cardiac failure with ejection fraction < 40%.
• Respiratory insufficiency (oxygen saturation < 90% or carbon dioxide partial pressure > 55 mm Hg [venous] or > 40 mm hydrargyrum [arterial] in room air or any ventilator use).
• Patients who are dependent on invasive or non-invasive ventilator support.
• Patients with major congenital anomaly or clinically significant intercurrent organic disease unrelated to Pompe disease.
• Patients not suitable for participation, whatever the reason, as judged by the Investigator, including medical or clinical conditions, or patients potentially at risk of noncompliance to study procedures.

The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.

Qualified researchers may request access to patient level data and related study documents including the clinical study report, study protocol with any amendments, blank case report form, statistical analysis plan, and dataset specifications. Patient level data will be anonymized and study documents will be redacted to protect the privacy of trial participants. Further details on Sanofi's data sharing criteria, eligible studies, and process for requesting access can be found at: https://vivli.org