Inclusion criteria:

• Patient or patient's parent or legal guardian has provided written informed consent after the nature of the study has been explained, and prior to any study-related procedures;
• Patient has been diagnosed with Pompe Disease prior to or during the screening period based on 2 GAA gene mutations and either: endogenous GAA activity <75% of the lower limit of the normal adult range reported by the testing laboratory, as assessed in cultured skin fibroblasts -or- endogenous GAA activity <75% of the lower limit of the normal adult range reported by the testing laboratory, as assessed by dried blood spot or whole blood assay;
• Patient is male or female and 13 years of age or older at the time of enrollment in the study;
• Sexually active patients must be willing to use an acceptable method of contraception while participating in the study and for at least 30 days following the last dose of BMN 701;
• If patient is female and not considered to be of childbearing potential, she is at least 2 years post-menopausal or had tubal ligation at least 1 year prior to screening, or who have had total hysterectomy;
• If patient is female and of childbearing potential, she has negative urine pregnancy tests during the Screening Period and at the Baseline visit and be willing to have additional pregnancy tests during the study;
• Patient has ≥30% predicted upright FVC and either <80% predicted upright FVC, or >10% reduction in supine FVC compared to upright FVC during the Screening Period;
• Patient is naïve to Enzyme Replacement Therapy (ERT) with rhGAA;
• Patient must be able to ambulate at least 40 meters (131.2 feet) on the 6MWT conducted at the Screening visit (use of assistive devices such as walker, cane, or crutches, is permitted); and
• Patient has the ability to comply with the protocol requirements, in the opinion of the Investigator.

Exclusion criteria:

• Patient has a history of diabetes or other disease known to cause hypoglycemia and is currently receiving, or might anticipate receiving, hypoglycemic agents during the course of the study;
• Patient has been on any immunosuppressive medication other than glucocorticosteroids within 1 year prior to enrollment into this study;
• Patient requires invasive ventilatory assistance at the time of enrollment into the study;
• Patient has received any investigational medication within 30 days prior to the first dose of study drug or is scheduled to receive any investigational drug other than BMN 701 during the course of the study;
• Patient has previously been admitted to the study;
• Patient is breastfeeding at screening or planning to become pregnant (self or partner) at any time during the study;
• Patient has a medical condition or extenuating circumstance that, in the opinion of the Investigator, might compromise the patient's ability to comply with the protocol requirements or compromise the patient's well being or safety;
• Patient has any condition that, in the view of the Investigator, places the patient at high risk of poor treatment compliance or of not completing the study.