Open-Label Study of Efficacy and Safety of Recombinant Human N-acetylgalactosamine 4-sulfatase in Patients With MPS VI

Inclusion Criteria: * Patient consent * Patient must be five years of age or older * Patient must have documented biochemical or genetic proof of MPS VI * Patient must walk at least 1 meter, but less than 250 meters, in the first 6 minutes of the baseline 12-minute walk test * If female of childbearing potential, patient must have a negative pregnancy test Exclusion Criteria: * Patient is under consideration for or has undergone a successful bone marrow transplant (BMT). * Pregnant or lactating patient * Patient has received an investigational drug within 30 days prior to study enrollment * Patient has been previously treated with rhASB * Patient has a medical condition, serious intercurrent illness, or other extenuating circumstance that may significantly confound study results or decrease study compliance * Patient has a known hypersensitivity to rhASB or to components of the study drug * History of cancer (except low grade and fully resolved skin malignancy)