title: Long-term, open-labeled extension study of idursulfase in the treatment of Hunter syndrome.
abstract: OBJECTIVE
  This study evaluated the safety and effectiveness of long-term enzyme replacement therapy with idursulfase (recombinant human iduronate-2-sulfatase) in patients with Hunter syndrome.
  
  
  METHODS
  All 94 patients who completed a 53-week double-blinded study of idursulfase enrolled in this open-labeled extension study and received intravenous idursulfase at a dose of 0.5 mg/kg weekly for 2 years, and clinical outcomes and safety were assessed.
  
  
  RESULTS
  No change in percent predicted forced vital capacity was seen, but absolute forced vital capacity demonstrated sustained improvement and was increased 25.1% at the end of the study. Statistically significant increases in 6-minute walking test distance were observed at most time points. Mean liver and spleen volumes remained reduced throughout the 2-year extension study. Mean joint range of motion improved for the shoulder and remained stable in other joints. Both the parent- and child-assessed Child Health Assessment Questionnaire Disability Index Score demonstrated significant improvement. Infusion-related adverse events occurred in 53% of patients and peaked at Month 3 of treatment and declined thereafter. Neutralizing IgG antibodies were detected in 23% of patients and seemed to attenuate the improvement in pulmonary function.
  
  
  CONCLUSIONS
  Weekly infusions of idursulfase result in sustained clinical improvement during 3 years of treatment.
authors.affiliation: Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. muenzer@med.unc.edu
authors.forename: Joseph
authors.initials: J
authors.lastname: Muenzer
authors.forename: Michael
authors.initials: M
authors.lastname: Beck
authors.forename: Christine M
authors.initials: CM
authors.lastname: Eng
authors.forename: Roberto
authors.initials: R
authors.lastname: Giugliani
authors.forename: Paul
authors.initials: P
authors.lastname: Harmatz
authors.forename: Rick
authors.initials: R
authors.lastname: Martin
authors.forename: Uma
authors.initials: U
authors.lastname: Ramaswami
authors.forename: Ashok
authors.initials: A
authors.lastname: Vellodi
authors.forename: James E
authors.initials: JE
authors.lastname: Wraith
authors.forename: Maureen
authors.initials: M
authors.lastname: Cleary
authors.forename: Muge
authors.initials: M
authors.lastname: Gucsavas-Calikoglu
authors.forename: Ana Cristina
authors.initials: AC
authors.lastname: Puga
authors.forename: Marwan
authors.initials: M
authors.lastname: Shinawi
authors.forename: Birgit
authors.initials: B
authors.lastname: Ulbrich
authors.forename: Suresh
authors.initials: S
authors.lastname: Vijayaraghavan
authors.forename: Susanne
authors.initials: S
authors.lastname: Wendt
authors.forename: Anne Marie
authors.initials: AM
authors.lastname: Conway
authors.forename: Alexandra
authors.initials: A
authors.lastname: Rossi
authors.forename: David A H
authors.initials: DA
authors.lastname: Whiteman
authors.forename: Alan
authors.initials: A
authors.lastname: Kimura
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D056947:Enzyme Replacement Therapy / Q000009:adverse effects / Q000379:methods*; D006025:Glycosaminoglycans / Q000032:analysis; D006801:Humans; D007066:Iduronate Sulfatase / Q000008:administration & dosage* / Q000009:adverse effects; D007262:Infusions, Intravenous; D008099:Liver / Q000473:pathology; D016532:Mucopolysaccharidosis II / Q000188:drug therapy* / Q000473:pathology; D009929:Organ Size; D013154:Spleen / Q000473:pathology; D016896:Treatment Outcome
chemical_list: D006025:Glycosaminoglycans; D007066:Iduronate Sulfatase; C517982:idursulfase