ARSB and mucopolysaccharidosis type 6: Previous phase 1, 2, and 3 studies have shown that treatment of individuals with MPS VI by ERT with recombinant human N-acetylgalactosamine 4-sulfatase (rhASB; galsulfase; Naglazyme®) is safe, rapidly reduces urinary GAG levels, and improves endurance as measured by 6- or 12-min walk and pulmonary function testing (Harmatz et al. 2004, 2005, 2006).