Clinical Trial: Safety and Clinical Outcomes in Hunter Syndrome Patients 5 Years of Age and Younger Receiving Idursulfase Therapy

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: A Multi-Center, Open-Label Study Evaluating Safety and Clinical Outcomes in Hunter Syndrome Patients 5 Years of Age and Younger Receiving Idursulfase Enzyme Replacement Th

Brief Summary: The objective of this study is to determine the safety of once weekly dosing of idursulfase 0.5 mg/kg administered by intravenous (IV) infusion for male Hunter syndrome patients ≤ 5 years old.

Detailed Summary:

This study will provide a basis for evaluating the safety of idursulfase administered to Hunter syndrome patients who are ≤ 5 years old. Additionally, this study will provide a basis for evaluating the idursulfase single- and repeated-dose pharmacokinetic profiles as well as the pharmacodynamic effect (as measured by urinary GAG excretion) in this pediatric population. Additional exploratory measures will include abdominal ultrasound measurements of liver and spleen volumes, assessments of growth with comparisons to normal population growth data, assessments of annualized growth velocity, assessments of routine developmental milestones using the Denver II, and assessments of clinical events, including the first occurrence of certain hearing-related events (e.g., hearing loss, otitis media), respiratory-related events (e.g., upper and lower respiratory infections), and specific surgical procedures (e.g., adenoidectomy, placement of PE tubes).

All patients in this open-label study will receive once-weekly infusions of idursulfase at a dose of 0.5 mg/kg.


Sponsor: Shire

Current Primary Outcome: Safety Evaluation [ Time Frame: From the start of study treatment until 30 days after the last infusion of idursulfase, up to 53 weeks ]

An adverse event (AE) was defined as any untoward medical occurrence in a clinical investigation participant administered as a pharmaceutical product that did not necessarily have a causal relationship with this treatment. A serious adverse event (SAE) was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly. Number of participants with AEs occurred after start of study treatment until 30 days after the last infusion of idursulfase, were reported.


Original Primary Outcome: Incidence of adverse events (including infusion-related adverse events), changes in 12-lead ECG, vital signs, standard laboratory parameters, and anti-idursulfase antibody status. [ Time Frame: One year ]

Current Secondary Outcome:

  • Mean Change From Baseline to Week 53 in Normalized Urinary Glycosaminoglycan (GAG) Levels [ Time Frame: Baseline, Weeks 18, 36 and 53 ]
    Analysis of urinary GAG levels was performed at baseline, Week 18, Week 36, and Week 53 as an assessment of the pharmacodynamic effects of Elaprase (idursulfase).
  • Single- and Repeat-Dose Pharmacokinetics - Maximum Observed Serum Concentration (Cmax) [ Time Frame: Weeks 1 and 27 ]
  • Single- and Repeat-Dose Pharmacokinetics - Time of Maximum Observed Serum Concentration (Tmax) [ Time Frame: Weeks 1 and 27 ]
  • Single- and Repeat-Dose Pharmacokinetics - Area Under the Serum Concentration-Time Curve From Time 0 to the Final Time Point With a Concentration of at Least Lower Limit of Quantitation (AUClast) [ Time Frame: Weeks 1 and 27 ]
  • Single- and Repeat-Dose Pharmacokinetics - Area Under the Serum Concentration-Time Curve From Time 0 to Infinity (AUCinf) [ Time Frame: Weeks 1 and 27 ]
  • Single- and Repeat-Dose Pharmacokinetics - Elimination Half-Life (t1/2) [ Time Frame: Weeks 1 and 27 ]
    t1/2 refers to the elimination of the drug. It is the time taken for the blood plasma concentration to reach half the concentration in the terminal phase of elimination. It is expressed in minutes and derived from the terminal slope of the concentration versus time curve.
  • Single- and Repeat-Dose Pharmacokinetics - Mean Residence Time From Time 0 to Infinity (MRTinf) [ Time Frame: Weeks 1 and 27 ]
    MRTinf is an average duration of the drug in the body from time zero to infinity, and is expressed in minutes.
  • Single- and Repeat-Dose Pharmacokinetics - Clearance (CL) [ Time Frame: Weeks 1 and 27 ]
    Clearance of a drug is a measure of the rate at which a drug is metabolized or eliminated by normal biological processes.
  • Single- and Repeat-Dose Pharmacokinetics - Volume of Distribution at Steady State (Vss) [ Time Frame: Weeks 1 and 27 ]
    Volume of distribution is defined as the theoretical volume in which the total amount of drug would need to be uniformly distributed to produce the desired blood concentration of a drug. Vss is the apparent volume of distribution at steadystate.


Original Secondary Outcome:

  • Mean change from Baseline to Week 53 in urinary GAG clearance (normalized for μg GAG/mg creatinine) [ Time Frame: One year ]
  • Single-dose and repeat-dose pharmacokinetic parameters [ Time Frame: Weeks 1 and 27 ]


Information By: Shire

Dates:
Date Received: January 22, 2008
Date Started: December 2007
Date Completion:
Last Updated: October 6, 2015
Last Verified: February 2014