Metachromatic leukodystrophy (MLD) is an inherited, autosomal recessive disorder of lipid metabolism characterized by deficient activity of the lysosomal enzyme, arylsulfatase A (ASA). MLD is a rare disease that occurs in most parts of the world. The estimated overall incidence of the disease in the western world is approximately 1 in 100,000 live births that varies by geographic location. There are no approved therapies for MLD.~This is a multicenter, open-label, dose-escalation study designed to evaluate the safety of up to 3 dose levels (10, 30, or 100 mg) of HGT-1110 administered via an intrathecal drug delivery device (IDDD) every other week (EOW) for a total of 38 weeks (20 injections, Weeks 0 to 38) to children with MLD. The study also includes the assessment of HGT-1110 drug product produced with a revised drug substance manufacturing process (referred to as Process B) in a fourth cohort (Cohort 4). Approximately 24 patients will be enrolled and will receive treatment of HGT-1110. Patients will be sequentially enrolled into 4 dose cohorts, approximately 6 patients each. Patient enrollment will be staggered in this study to facilitate adequate safety monitoring per dose cohort.
The purpose of this study is to determine the safety of ascending doses of HGT-1110 administered by intrathecal (IT) injection for 38 weeks (20 injections) in children with metachromatic leukodystrophy (MLD).