Primary Objective: Long-term safety and pharmacokinetics (PK) of avalglucosidase alfa Secondary Objective: Long-term effect of avalglucosidase alfa on pharmacodynamic variables
The planned duration of the study for each participant was initially 6 years. Each participant continued with the study until the participant withdrew, the Investigator withdrew the participant, or the Sponsor terminated the study. An additional follow-up phase began after the participant has completed the 6-year study period, and lasted until avalglucosidase alfa was approved in the participant's country, except in the United Kingdom (UK), Germany and Denmark, where the duration of the additional follow-up phase was up to the approval in the country or limited to a maximum of 2 years, whichever occurred first (ie, for participants in the UK, Germany and Denmark, the total study duration per participant was 8 years at the maximum including the initial 6-year period and the additional 2-year follow-up).
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
19
Pharmaceutical form: lyophilized powder reconstituted for infusion Route of administration: intravenous
Investigational Site Number 840006
Phoenix, Arizona, United States
Investigational Site Number 840010
Jacksonville, Florida, United States
Number of Participants With Treatment-Emergent Adverse Events (TEAEs), Treatment-Emergent Serious Adverse Events (TESAEs), Infusion Associated Reactions (IARs) and Deaths
An adverse event (AE) is any untoward medical occurrence in a participant or clinical investigation participant administered a pharmaceutical product and which does not necessarily have to have a causal relationship with the treatment. An serious AE (SAE) is any untoward medical occurrence that results: death or life-threatening or inpatient hospitalization or prolongation of existing hospitalization or persistent or significant disability or congenital anomaly or medically important event. TEAEs are defined as AEs that develop or worsen during the on-treatment period (that is, from the time of first dose of IMP up to 4 weeks after the last administration of the IMP). Protocol-defined IARs were defined as AEs that occur during either the infusion or the post-infusion observation period (that is, up to 2 hours or longer following the infusion as per the Investigator's discretion) which were deemed to be related or possibly related to the IMP.
Time frame: From first dose of IMP up to 4 weeks after the last treatment administration of the IMP, a maximum up to 458 weeks
Number of Participants With Clinically Significant Physical Examination Abnormalities
Physical examination included, at a minimum, an assessment of the participant's general appearance; skin; head, eyes, ears, nose, and throat; examinations of lymph nodes, abdomen, extremities/joints, neurological and mental status; heart and respiratory auscultation; peripheral arterial pulse; and pupil, knee, achilles, and plantar reflexes.
Time frame: From first dose of IMP up to 4 weeks after the last treatment administration of the IMP, a maximum up to 458 weeks
Number of Participants With Potentially Clinically Significant Abnormalities in Biochemistry
Blood samples were collected to determine the clinical chemistry laboratory abnormalities.
Time frame: From first dose of IMP up to 4 weeks after the last treatment administration of the IMP, a maximum up to 458 weeks
Number of Participants With Potentially Clinically Significant Abnormalities in Hematology
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Investigational Site Number 840001
Kansas City, Kansas, United States
Investigational Site Number 840008
St Louis, Missouri, United States
Investigational Site Number 840002
Durham, North Carolina, United States
Investigational Site Number 840011
Cincinnati, Ohio, United States
Investigational Site Number 840009
Dallas, Texas, United States
Investigational Site Number 840003
Fairfax, Virginia, United States
Investigational Site Number 056001
Leuven, Belgium
Investigational Site Number 208001
København Ø, Denmark
...and 7 more locations
Blood samples were collected to determine the hematology laboratory significant abnormalities.
Time frame: From first dose of IMP up to 4 weeks after the last treatment administration of the IMP, a maximum up to 458 weeks
Change From Baseline in Urine BUN up to Last IMP Administration
Last on-treatment (LOT) values were collected at or just prior to the last IMP administration.
Time frame: Baseline (Day 1) and last on-treatment values (up to 454 weeks)
Change From Baseline in Urine Hyaline Casts up to Last IMP Administration
The LOT values were collected at or just prior to the last IMP administration.
Time frame: Baseline (Day 1) and last on-treatment values (up to 454 weeks)
Change From Baseline in Urine Leukocytes [White Blood Cell (WBC)] up to Last IMP Administration
The LOT values were collected at or just prior to the last IMP administration.
Time frame: Baseline (Day 1) and last on-treatment values (up to 454 weeks)
Change From Baseline in Urine Specific Gravity up to Last IMP Administration
The LOT values were collected at or just prior to the last IMP administration.
Time frame: Baseline (Day 1) and last on-treatment values (up to 454 weeks)
Change From Baseline in Urine pH up to Last IMP Administration
The LOT values were collected at or just prior to the last IMP administration.
Time frame: Baseline (Day 1) and last on-treatment values (up to 454 weeks)
Number of Participants With Potentially Clinically Significant Vital Signs Abnormalities
Participants vital signs were examined to determine the abnormalities. Vital signs included heart rate, systolic and diastolic blood pressure.
Time frame: From first dose of IMP up to 4 weeks after the last treatment administration of the IMP, a maximum up to 458 weeks
Number of Participants With Body Weight Increased/Decreased
Body weight was measured in kilograms and collected in the electronic case report forms every 3 months throughout the duration of the study, as well as at the end of study visit.
Time frame: From first dose of IMP up to 4 weeks after the last treatment administration of the IMP, a maximum up to 458 weeks
Number of Participants With Potentially Clinically Significant 12-Lead Electrocardiogram (ECG) Abnormalities
Standard 12-lead ECGs were recorded after at least 15 minutes in the supine position using an electrocardiographic device. The following were assessed: heart rate, rhythm, interval between the peaks of successive QRS complexes (RR), interval from the beginning of the P wave until the beginning of the QRS complex (PR), interval from start of the Q wave to the end of the S wave (QRS), interval between the start of the Q wave and the end of the T wave (QT), QT interval corrected for heart rate (QTc) automatic correction evaluation (by the ECG device), QRS axis, R voltage V6, voltage V1, left ventricular hypertrophy criteria, right ventricular hypertrophy criteria, repolarization charges, and overall cardiac impression for each participant.
Time frame: From first dose of IMP up to 4 weeks after the last treatment administration of the IMP, a maximum up to 458 weeks
Number of Participants With Antidrug Antibodies (ADA) Status, Positive or Negative
ADA negative was defined as ADAs are not detected (that is, negative in screening assay or reactive in screening but negative in confirmatory assay). ADA positive was defined as ADA was detected (that is, an assay signal equal to or greater than the cut-point in the screening assay and was tested positive in the confirmatory assay).
Time frame: From first dose of IMP up to 4 weeks after the last treatment administration of the IMP, a maximum up to 458 weeks
Maximum Observed Plasma Concentration (Cmax) of Avalglucosidase Alfa
Cmax was defined as maximum plasma concentration observed. The non-compartmental pharmacokinetic (PK) analysis was performed.
Time frame: Predose (prior to infusion), end of the infusion and at 1, 4, 8, 12, and 24 hours post-dose on Week 312
Area Under the Plasma Concentration Versus Time Curve From Time Zero to the Real Time (AUClast) of Avalglucosidase Alfa
AUClast was calculated using the trapezoidal method from time zero to the real time. The non-compartmental PK analysis was performed.
Time frame: Predose (prior to infusion), end of the infusion and at 1, 4, 8, 12, and 24 hours post-dose on Week 312
Time Corresponding to the Last Concentration (Tlast) of Avalglucosidase Alfa
Tlast was defined as time corresponding to the last concentration above the limit of quantification, Clast. The non-compartmental PK analysis was performed.
Time frame: Predose (prior to infusion), end of the infusion and at 1, 4, 8, 12, and 24 hours post-dose on Week 312
Terminal Half-Life (t1/2z) of Avalglucosidase Alfa
t1/2z was calculated according to the following equation: t1/2z = 0.693/λz. Where, λz is the slope of the regression line of the terminal phase of the plasma concentration versus time curve. Half-life was calculated by taking the regression of at least 3 points. The non-compartmental PK analysis was performed.
Time frame: Predose (prior to infusion), end of the infusion and at 1, 4, 8, 12, and 24 hours post-dose on Week 312
Apparent Total Body Clearance Steady-State (CLss) of Avalglucosidase Alfa
CLss was calculated using the following equation: CLss= dose/AUC. The non-compartmental PK analysis was performed.
Time frame: Predose (prior to infusion), end of the infusion and at 1, 4, 8, 12, and 24 hours post-dose on Week 312
Apparent Volume of Distribution Steady-State (Vss) of Avalglucosidase Alfa
Vss was calculated using the following equation: Vz= CLss/λz. The non-compartmental PK analysis was performed.
Time frame: Predose (prior to infusion), end of the infusion and at 1, 4, 8, 12, and 24 hours post-dose on Week 312
Change From Baseline in Cross-Sectional Area (CSA) of Skeletal Muscle Magnetic Resonance Imaging (MRI) Up to Week 442
Skeletal muscle MRI performed prior to the muscle needle or open biopsy procedure using both qualitative (T1) and quantitative (T2, dixon) modalities to assess disease severity and detect treatment effects. The T1 weighted axial data was analyzed using the mercuri scale, which determines degree of intact muscle and fatty replacement, providing a qualitative measure of overall disease severity. Trophicity changes were evaluated for 5 muscle groups, including the upper leg muscles (quadriceps, hamstring) and the lower leg muscles (triceps, extensors, fibularis). The measured area of each muscle group, CSA was provided.
Time frame: Baseline (Day 1) and Weeks 104 and 442
Change From Baseline in Dixon Fat Fraction of Skeletal Muscle Magnetic Resonance Imaging (MRI) Up to Week 442
Skeletal muscle MRI performed prior to the muscle needle or open biopsy procedure using both qualitative (T1) and quantitative (T2, dixon) modalities to assess disease severity and detect treatment effects. The T1 weighted axial data was analyzed using the mercuri scale, which determines degree of intact muscle and fatty replacement, providing a qualitative measure of overall disease severity. Trophicity changes were evaluated for 5 muscle groups, including the upper leg muscles (quadriceps, hamstring) and the lower leg muscles (triceps, extensors, fibularis). Three-point dixon imaging provided quantification of fat content in muscles \[fat fraction (FF)\].
Time frame: Baseline (Day 1) and Weeks 104 and 442
Change From Baseline in Index of Real Muscle Mass (IRMM) of Skeletal Muscle Magnetic Resonance Imaging (MRI) Up to Week 442
Skeletal muscle MRI performed prior to the muscle needle or open biopsy procedure using both qualitative (T1) and quantitative (T2, dixon) modalities to assess disease severity and detect treatment effects. The T1 weighted axial data was analyzed using the mercuri scale, which determines degree of intact muscle and fatty replacement, providing a qualitative measure of overall disease severity. Trophicity changes were evaluated for 5 muscle groups, including the upper leg muscles (quadriceps, hamstring) and the lower leg muscles (triceps, extensors, fibularis). The FF was combined with the CSA measurements trophicity to provide an IRMM in mm\^2 (that is, IRMM = CSA x \[1 - FF\]). A negative change from baseline value in IRMM of skeletal muscle MRI indicates muscle loss (worse outcome) and a positive change from baseline value indicates muscle gain (better outcome).
Time frame: Baseline (Day 1) and Weeks 104 and 442
Change From Baseline in T2 of Skeletal Muscle Magnetic Resonance Imaging (MRI) Up to Week 442
Skeletal muscle MRI performed prior to the muscle needle or open biopsy procedure using both qualitative (T1) and quantitative (T2, dixon) modalities to assess disease severity and detect treatment effects. The T1 weighted axial data was analyzed using the mercuri scale, which determines degree of intact muscle and fatty replacement, providing a qualitative measure of overall disease severity. Trophicity changes were evaluated for 5 muscle groups, including the upper leg muscles (quadriceps, hamstring) and the lower leg muscles (triceps, extensors, fibularis). The T2 multi-slice multi-spin echo and B1 mapping provided a quantitative measure of disease activity (edema, inflammation) within muscles.
Time frame: Baseline (Day 1) and Weeks 104 and 442
Change From Baseline in T2 With B1 of Skeletal Muscle Magnetic Resonance Imaging (MRI) Up to Week 442
Skeletal muscle MRI performed prior to the muscle needle or open biopsy procedure using both qualitative (T1) and quantitative (T2, dixon) modalities to assess disease severity and detect treatment effects. The T1 weighted axial data was analyzed using the mercuri scale, which determines degree of intact muscle and fatty replacement, providing a qualitative measure of overall disease severity. Trophicity changes were evaluated for 5 muscle groups, including the upper leg muscles (quadriceps, hamstring) and the lower leg muscles (triceps, extensors, fibularis). The T2 multi-slice multi-spin echo and B1 mapping provided a quantitative measure of disease activity (edema, inflammation) within muscles.
Time frame: Baseline (Day 1) and Weeks 104 and 442
Change From Baseline in Skeletal Muscle Biopsy Up to Week 312
Skeletal muscle needle or open biopsy was performed on the lower extremity (quadriceps) muscle to assess glycogen content. The MRI appearance of the muscle was used to determine the level (axial slice position) that the biopsy procedure should target (avoiding fatty replaced tissue). Glycogen content was measured by histomorphometric analysis or severity grading to determine how effectively avalglucosidase alfa was able to remove glycogen from muscle.
Time frame: Baseline (Day 1) and Weeks 27, 104, 208, 260 and 312
Change From Baseline in Urinary Glucose Tetrasaccharide (Hex4) Level Up to Week 442
The Hex4, a tetraglucose oligomer, has been shown to be elevated in the urine of participants with Pompe disease. Hence, determination of Hex4 levels may be a means by which the efficacy of treatments were monitored. Urine samples were collected prior to IMP infusion for the assessment of urinary Hex4 concentrations.
Time frame: Baseline (Day 1) and Weeks 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 52, 78, 104, 130, 156, 182, 208, 234, 260, 286, 312, 338, 364, 390, 416 and 442