Study 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 diagnosis of MPS VI, confirmed at screening by measurable clinical signs and symptoms of MPS VI Leukocyte ASB enzyme activity level less than 20% of the normal range Clinical evidence of significant MPS VI disease that provides adequate opportunity to achieve quantitative, short-term therapeutic benefit in three or more of the following parameters: endurance (as measured by a six-minute walk test), forced vital capacity (as measured by spirometry), joint range of motion, urinary glycosaminoglycans, and hepatomegaly. Ability to perform all protocol tests Ability to stand independently for six minutes Sexually active subjects must agree to use an adequate form of contraception Exclusion Criteria: History of bone marrow transplantation Pregnant or lactating patient Use of an investigational drug or device within 30 days prior to study participation. A medical condition, serious intercurrent illness, or other extenuating circumstances that may significantly decrease study compliance including prescribed follow-up Known hypersensitivity to rhASB or to components of the study drug History of cancer (except low grade and fully resolved skin malignancy)