Title

Replagal Enzyme Replacement Therapy for Children With Fabry Disease
An Open Label Clinical Trial of Replagal Enzyme Replacement Therapy In Children With Fabry Disease Who Have Completed Study TKT023 or Who Are Naive to Enzyme Replacement Therapy
  • Phase

    Phase 2
  • Study Type

    Interventional
  • Study Participants

    17
Primary Objective(s):

To assess the safety of Replagal at a dose of 0.2 mg/kg administered over 40 (+/-10) minutes in children with Fabry disease
To assess the effect of Replagal on heart rate variability in patients 7 to 17 years of age

Secondary Objective(s):

To determine the pharmacokinetics of Replagal at baseline and after the initiation of enzyme replacement therapy (ERT)
To determine exploratory measurements of efficacy including renal function (ie, estimated glomerular filtration rate [eGFR] and creatinine clearance), clinical outcomes (in Cohorts 1 and 2), and sweating and left ventricular mass index (LVMI) (Cohort 1, Phase 1 only)
TKT029 is an open label multi-center study to assess the safety of enzyme replacement therapy with Replagal (agalsidase alfa) in children with Fabry disease, who have completed 6 months of agalsidase alfa therapy in study TKT023 (Cohort 1) or who are treatment-naïve (Cohort 2) and meet all inclusion/exclusion criteria of this study. The study will consist of every other week treatment with Replagal for 52 weeks, with periodic reassessments by Shire HGT for continuation of the study beyond 52 weeks. A decision on the part of the study sponsor to terminate the study may be made at any time.

In Cohort 1, safety and clinical measurement assessments performed during Week 25 or 26 of Study TKT023 served as the baseline assessments for TKT029. Patients in Cohort 1 began treatment with Replagal manufactured using a roller bottle process (Replagal RB); this portion of treatment is denoted as Cohort 1, Phase 1. Safety evaluation visits for Cohort 1, Phase 1 were to be performed at Weeks 13, 25, 55, and every 26 weeks thereafter until the patient discontinued from the study or transitioned to treatment with Replagal manufactured using a bioreactor process (Replagal AF). The transition to Replagal AF marked the restart of the study clock and was denoted as Cohort 1, Phase 2. Safety evaluation visits for Cohort 1, Phase 2 will be performed at Weeks 1, 13, 25, 55, and every 26 weeks thereafter until the patient discontinues from or the sponsor terminates the study.

Patients in Cohort 2 will receive treatment with Replagal AF only; therefore there is only 1 study phase for these patients. Screening assessments performed at Week -1 will serve as the baseline assessments for this study. Safety evaluation visits for Cohort 2 will be performed at Weeks 13, 25, 37, 55 and every 26 weeks thereafter until the patients discontinues from or the sponsor terminates the study.

The final study visit for both cohorts will follow 30 days after the study study drug infusion, at which time a final safety evaluation will be performed. Patients who complete the study will be interviewed by telephone 30 days after their last study infusion for resolution of any outstanding adverse events (AEs) or concomitant medication changes. Any patient who withdraws early from the study will have a final study visit 30 days after the last study drug infusion, at which time a final safety evaluation will be performed.
Study Started
Jun 10
2004
Primary Completion
Jun 15
2011
Study Completion
Jun 15
2011
Results Posted
Oct 10
2013
Estimate
Last Update
Jul 30
2021

Drug Agalsidase alfa

0.2 mg/kg agalsidase alfa administered by IV infusion over 40 (+/- 10) minutes every other week for 52 weeks, with periodic reassessments for study continuation beyond 52 weeks

  • Other names: Replagal

Agalsidase alfa (Cohort 1) Experimental

Cohort 1: Patients who completed TKT023.

Agalsidase Alfa (Cohort 2) Experimental

Cohort 2: Treatment-naive patients.

Criteria

Inclusion Criteria:

1a. For Cohort 1 (both phases):

- Patients must have completed all study requirements and assessments for Study TKT023 less than 30 (+/-7) days prior to enrolling in Study TKT029 and must have no safety or medical issues that contraindicate participation.

OR

1b. For Cohort 2:

The patient is between 7 and 17 years of age at the time of informed consent, inclusive.
The patient must be ERT-naive.
The patient is a hemizygous male with Fabry disease as confirmed by a deficiency of alpha-galactosidase A activity measured in serum, leukocytes, or fibroblasts. Male patients who do not already have a documented deficiency of alpha-galactosidase A activity will provide a blood sample during screening for determination of alpha-galactosidase A activity level in their serum.

OR

- The patient is a heterozygous female or hemizygous male with Fabry disease as confirmed by a mutation of the alpha-galactosidase A gene. Patients who do not already have a documented mutation of the alpha-galactosidase A gene will provide a blood sample during screening for genotyping.

2. Adequate general health (as determined by the Investigators) to undergo the specified phlebotomy regimen and protocol-related procedures and no safety or medical contraindications for participation.

3. The minor child must assent to participate in the protocol and the parent(s) or legally authorized guardian(s) must have voluntarily signed an Institutional Review Board/Independent Ethics Committee (IRB/IEC) approved informed concent form after all relevant aspects of the study have been explained and discussed with the child and the child's parent(s) or legal guardian(s).

Exclusion Criteria:

Patients who meet any of the following criteria are not eligible for this study:

Patient and/or the patient's parent(s) or legal guardian(s) are unable to understand the nature, scope, and possible consequences of the study.
Patient is unable to comply with the protocol, e.g., uncooperative with protocol schedule, refusal to agree to all of the study procedures, inability to return for safety evaluations, or is otherwise unlikely to complete the study, as determined by the Investigator or the medical monitor.

Summary

Safety Population RB

Transition Safety Population

All Events

Event Type Organ System Event Term Safety Population RB Transition Safety Population

Patients Who Experienced At Least One Adverse Event (AE)

Agalsidase Alfa (Cohort 1)

17.0
participants

Pharmacokinetics - Area Under the Serum Concentration-Time Curve (AUC0-∞) - Week 315/341

AUC0-∞ is a measure of the total exposure to a drug.

Agalsidase Alfa (Cohort 1)

213193.0
min·U/mL (Mean)
Standard Deviation: 119581

Pharmacokinetics - Maximum Observed Serum Concentration (Cmax) - Week 81

Cmax is the peak plasma concentration of a drug after administration.

Agalsidase Alfa (Cohort 1)

3173.0
U/mL (Mean)
Standard Deviation: 969

Pharmacokinetics - Maximum Observed Serum Concentration (Cmax) - Week 133

Cmax is the peak plasma concentration of a drug after administration.

Agalsidase Alfa (Cohort 1)

3842.0
U/mL (Mean)
Standard Deviation: 1235

Pharmacokinetics - Maximum Observed Serum Concentration (Cmax) - Week 159

Cmax is the peak plasma concentration of a drug after administration.

Agalsidase Alfa (Cohort 1)

3842.0
U/mL (Mean)
Standard Deviation: 1235

Pharmacokinetics - Maximum Observed Serum Concentration (Cmax) - Week 315/341

Cmax is the peak plasma concentration of a drug after administration.

Agalsidase Alfa (Cohort 1)

3568.0
U/mL (Mean)
Standard Deviation: 1492

Pharmacokinetics - Area Under the Serum Concentration-Time Curve (AUC0-∞) - Week 133

AUC0-∞ is a measure of the total exposure to a drug.

Agalsidase Alfa (Cohort 1)

295779.0
min·U/mL (Mean)
Standard Deviation: 161058

Pharmacokinetics - Area Under the Serum Concentration-Time Curve (AUC0-∞) - Week 159

AUC0-∞ is a measure of the total exposure to a drug.

Agalsidase Alfa (Cohort 1)

218078.0
min·U/mL (Mean)
Standard Deviation: 73560

Pharmacokinetics - Area Under the Serum Concentration-Time Curve (AUC0-∞) - Week 81

AUC0-∞ is a measure of the total exposure to a drug.

Agalsidase Alfa (Cohort 1)

245282.0
min·U/mL (Mean)
Standard Deviation: 159071

Heart Rate Variability - Change From Baseline at Week 185 in SDNN

Heart rate variability was assessed by 2-hour Holter monitoring. Standard deviation of all filtered RR intervals over the length of the analysis (SDNN) was measured.

Agalsidase Alfa (Cohort 1)

20.256
msec (Mean)
Standard Deviation: 29.060

Age, Continuous

11.99
years (Mean)
Standard Deviation: 3.2464

Baseline Heart Rate Variability (SDNN)

98.947
msec (Mean)
Standard Deviation: 32.324

Race/Ethnicity, Customized

Sex: Female, Male

Phase 1 (Treatment With Replagal RB)

Agalsidase Alfa (Cohort 1)

Phase 2 (Transition to Replagal AF)

Agalsidase Alfa (Cohort 1)

Drop/Withdrawal Reasons

Agalsidase Alfa (Cohort 1)