Primary Objective:

To evaluate the effect of one-year Alglucosidase alfa treatment on motor function [Six-minute walk test (6MWT) and lung function predicted Forced vital capacity (FVC)] among Chinese Late Onset Pompe Disease patients above 5 years old.

To evaluate the safety of Myozyme 20mg/kg, IV biweekly in Chinese LOPD patients above 3 years old.

Secondary Objective:

To evaluate the effect of one-year treatment with Alglucosidase alfa on improvement of manual muscle test (MMT), Maximal inspiratory and expiratory pressure (MIP and MEP)], Quick Motor Function Test scores, and health-related quality of life (SF-12) among LOPD patients over 5 years old.

Study duration per participants is approximatively 56 weeks including a 52-week treatment period.

Inclusion criteria :

• Patients (or and patient's legal guardian) must provide written informed consent prior to any study-related procedures

• The patient must be ≥ 3 years of age at the time of enrollment.

  1. For patient ≥ 3-year and < 5-year old: must be able to walk 10 meters or climb 4-step stairs independently.
  2. For patients ≥5-year old

  i. Must be able to ambulate 40 meters in 6 minutes without assistance ii. Must be able to successfully perform repeated forced vital capacity (VC) measurements in upright position of ≥ 30% predicted and ≤85% predicted.

• The patient has confirmed Pompe's Disease with at least 2 of the following condition,

  1. GAA enzyme deficiency from any tissue source.
  2. 2 confirmed GAA gene mutations.
  3. muscle pathology meet the diagnosis of Pompe disease.

• The patient (and patient's legal guardian if patient is legally minor as defined by local regulation) must have the ability to comply with the clinical protocol.

• The patient, if female and of childbearing potential, must have a negative pregnancy test (beta-human chorionic gonadotropin) at baseline.

Exclusion criteria:

• Use of invasive ventilatory support (Invasive ventilation is defined as any form of ventilatory support applied with the use of an endotracheal tube.)
• Use of non-invasive ventilatory support while awake and in an upright position. (Non-invasive ventilation is defined as any form of ventilatory support applied without the use of an endotracheal tube.)
• Previously treated with Enzyme Replacement Treatment.
• A Female patient of childbearing potential with a positive pregnancy test.
• Wheelchair dependent.
• The patient has a major congenital anomaly.
• The patient has a medical condition, serious intercurrent illness, or other extenuating circumstance, in the opinion of the Investigator, may significantly interfere with study compliance, including all prescribed evaluations and follow-up activities.
• The patients with ≥5-year old are unable to ambulate 40 meters without assistance or unable to successfully perform repeated FVC of >30% and <85% predicted (upright).

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