Study of Recombinant Human N-acetylgalactosamine 4-sulfatase (rhASB) in Patients With MPS VI

Inclusion Criteria * Patient consent * Patient must be seven years of age or older * Patient must have documented biochemical or genetic proof of MPS VI * The patient must be able to walk independently at least 5 meters and no more than 270 meters in the first 6 minutes, or no more then 400 meters total in 12 minutes, in the screening 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) * Patient refuses or is unable to complete all screening evaluations * 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 * The patient has clinically significant spinal cord compression * The patient has known hypersensitivity to rhASB or to components of the active or placebo test solutions