Overall safety summary of patients experiencing Adverse Events (AEs), Serious Adverse Events (SAEs), treatment-related AEs, and Infusion Associated Reactions (IARs). Summary is based on Treatment-emergent AEs (TEAEs), defined as AEs that occurred following the initiation of study treatment, i.e., alglucosidase alfa or placebo.

Mean distance walked gives an indication of functional endurance. The greater the distance, the greater the endurance. Mean values of distance walked in a six-minute walk test are offered for baseline, week 78 (or last available observation), and the mean change from baseline (at week 78 or last available post-baseline observation).

Forced vital capacity is a standard pulmonary function test used to quantify respiratory muscle weakness. Forced vital capacity (FVC) is the volume of air that can forcibly be blown out after full inspiration in the upright position, measured in liters. Predicted forced vital capacity is based on a formula using sex, age and height of a person, and is an estimate of healthy lung capacity. Percent of predicted FVC = (observed value)/(predicted value) \* 100%.

Area under the plasma concentration versus time curve from time zero (pre-dose) to 16 hours after the end of infusion. Blood sample time points were 0 (before the start of the infusion), 1 and 2 hours after the start of infusion, end of the infusion, and then 0.25, 0.5, 1, 2, 3, 4, 8, 12,and 16 hours after the end of the infusion (with a 5-minute window for time-points after the start of infusion). Pooled figures combine the values for the three timeframes.

Maximum plasma concentration observed in blood samples taken at the following time points: 0 (before the start of the infusion), 1 and 2 hours after the start of infusion, end of the infusion, and then 0.25, 0.5, 1, 2, 3, 4, 8, 12,and 16 hours after the end of the infusion (with a 5-minute window for time-points after the start of infusion). Pooled figures combine the values for the three timeframes.

Time to maximum plasma concentration observed in blood samples taken at the following time points: 0 (before the start of the infusion), 1 and 2 hours after the start of infusion, end of the infusion, and then 0.25, 0.5, 1, 2, 3, 4, 8, 12,and 16 hours after the end of the infusion (with a 5-minute window for time-points after the start of infusion). Pooled figures combine the values for the three timeframes.