Study to Evaluate Efficacy and Safety in Chinese Patients With Late Onset Pompe Disease With Alglucosidase Alfa Treatmen

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

• ALGLUCOSIDASE ALFA (Drug), also known as MYOZYME: Pharmaceutical form:solution for infusion Route of administration: intravenous

Primary outcomes

• Change from baseline in Six-minute walk test (6MWT) for the patients ≥5-year old [Baseline to 12 months]: This test measures the distance that a patient can quickly walk on a flat, hard surface in a period of 6 minutes.
• Change from baseline in percent predicted forced vital capacity (%FVC) in upright position for the patients ≥5-year old [Baseline to 12 months]: The measurements of pulmonary function and respiratory strength including FVC, MEP and MIP use a pneumograph or the spirometry system with the patient in upright seated and supine positions, according to American Thoracic Society (ATS) and European Respiratory Society (ERS) guidelines.
• Number of participants with adverse events Number of AEs [From signing the ICF to the 30th day after the last dosage of the study medications]: An adverse event (AE) is any untoward medical occurrence in a patient or clinical investigation patient administered a pharmaceutical product and which does not necessarily have to have a causal relationship with this treatment.

Secondary outcomes

• Change from baseline in maximal inspiratory pressure (MIP) in upright position for the patients ≥5-year old [Week 52]: The measurements of pulmonary function and respiratory strength including FVC, MEP and MIP use a pneumograph or the spirometry system with the patient in upright seated and supine positions, according to American Thoracic Society (ATS) and European Respiratory Society (ERS) guidelines.
• Change from baseline in maximal expiratory pressure (MEP) in upright position for the patients ≥5-year old [Week 52]: The measurements of pulmonary function and respiratory strength including FVC, MEP and MIP use a pneumograph or the spirometry system with the patient in upright seated and supine positions, according to American Thoracic Society (ATS) and European Respiratory Society (ERS) guidelines.
• Change from baseline in manual muscle test (MMT) for deltoid muscle, quadriceps femoris, iliopsoas, neck stretch flexor for the patients ≥5-year old [Week 52]: MMT has been reported most often as a summary score of a total number of proximal, distal, and axial muscle groups tested bilaterally or as a proximal score that sums a number of proximal muscle groups from the upper and lower extremities.
• Change from baseline in Quick Motor Function Test scores for the patients ≥5-year old [Week 52]: The Quick Motor Function Test is a reliable and valid test for assessing motor function in patients with Pompe's disease.
• Change from baseline in Quick Motor Function Test scores for the patients ≥5-year old [Week 52]: The 12-Item Short Form Health Survey (SF-12) was developed for the Medical Outcomes evaluation of patients with chronic conditions.

Sex: All, ages: 3 Years to any

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.

• Clinical Sciences & Operations, Study director, Sanofi