Conditions: Mucopolysaccharidosis I Hurler Syndrome
Keywords: Laronidase ERT Stem cell transplant storage disease inborn errors of metabolism hurler syndrome glycosaminoglycans enzyme replacement
Allocation: NA | Intervention model: SINGLE_GROUP
Enrollment: 25
Healthy volunteers: no

Brief summary:
The investigators hypothesize that weekly infusions of Laronidase ERT for 10-12 weeks prior to transplant and 8 weeks following transplant will result in a reduction of glycosaminoglycans (GAG) burden that is associated with decreased complications following transplant.

Detailed description:
Subjects will receive laronidase once a week intravenously for 10-12 weeks prior to transplant and for approximately 8 weeks after transplant. Laronidase will be given by intravenous infusion (IV) through a catheter and from there to your child's body's cells and organs to break down the glycosaminoglycans (GAG) buildup.

Prior to starting ERT, subjects will have a complete physical examination, which includes a complete assessment of your child's airway and lungs. In addition to standard treatment evaluations and tests, which are done prior to hematopoietic stem cell transplant (HSCT), subjects will have the following tests: an additional teaspoon of blood for a baseline test for serum antibodies against laronidase, before and after the fourth dose of laronidase, the investigators will collect 2 teaspoons of blood for an alpha-L-iduronidase enzyme level; to watch for side effects to laronidase and the development of antibodies to laronidase, approximately 2 teaspoons of blood will be collected every 3 weeks while the subject is receiving laronidase ERT.

Arms:
arm 1: Weekly infusion of laronidase enzyme replacement therapy followed by hematopoietic stem cell transplant.

Interventions: intervention 1: Stem Cell Transplant intervention 2: Laronidase ERT
Intervention descriptions: intervention 1: enzyme replacement 10-12 weeks prior to hematopoietic stem cell transplant (HSCT), and 8 weeks following intervention 2: Laronidase ERT will be administered 10-12 weeks prior to HSCT, and 8 weeks following.

Protocol document: