For the treatment of Hunter syndrome in adults and children ages 5 and older.
Hunter's Syndrome is an X-linked recessive disease caused by insufficient levels of the lysosomal enzyme iduronate-2-sulfatase. This enzyme cleaves the terminal 2-O-sulfate moieties from the glycosaminoglycans (GAG) dermatan sulfate and heparan sulfate. Due to the missing or defective iduronate-2-sulfatase enzyme in patients with Hunter's Syndrome, GAG progressively accumulate in the lysosomes of a variety of cells, leading to cellular engorgement, organomegaly, tissue destruction and organ system dysfunction. Treatment of Hunter's Syndrome patients with idursulfase provides exogenous enzyme for uptake into cellular lysosomes. Targeting of idursulfase to the lysosome occurs by endocytosis from the cell surface. Mannose-6-phosphate (M6P) residues on the oligosaccharide chains allow specific binding of the enzymes to the M6P receptors on the cell surface, leading to cellular internalization of the enzyme, targeting to intracellular lysosomes and subsequent catabolism of accumulated GAG.
There is no experience with overdosage of Idursulfase in humans. Single intravenous doses of idursulfase up to 20 mg/kg were not lethal in male rats and cynomolgus monkeys (approximately 6.5 and 13 times, respectively, of the recommended human dose based on body surface area) and there were no clinical signs of toxicity.
44 ± 19 minutes
* 3 mL/min/kg [Patients (7.7 – 27 years) with Hunter syndrome with treatment week 1(0.5 mg/kg ELAPRASE administered weekly as a 3-hour infusion)] * 3.4 mL/min/kg [patients (7.7 – 27 years) with Hunter syndrome with treatment week 27 (0.5 mg/kg ELAPRASE administered weekly as a 3-hour infusion)]