Number of Participants With Adverse Events
An adverse event is any noxious, pathologic, or unintended change in anatomical, physiologic, or metabolic function as indicated by physical signs, symptoms, or laboratory changes occurring in any phase of a clinical study, whether or not considered investigational product-related.
Number of Participants With Clinically Significant Changes in Vital Signs, Laboratory Parameters, and 12-lead Electrocardiogram (ECG) Findings
Number of participants with clinically significant changes will be reported.
Maximum Observed Serum Concentration (Cmax) of Idursulfase
The Cmax of Idursulfase will be assessed.
Maximum Observed Concentration (Cmax) of Idursulfase in Cerebrospinal Fluid (CSF)
The Cmax of Idursulfase in CSF will be assessed.
Change From Baseline in the Concentration of Glycosaminoglycan (GAG) in Cerebrospinal Fluid (CSF)
Concentration of GAG in CSF will be assessed.
Change From Baseline in the Concentration of Glycosaminoglycan (GAG) in Urine
Concentration of GAG in urine will be assessed.
Number of Participants who Report Anti-idursulfase Antibodies in Cerebrospinal Fluid (CSF)
The presence of idursulfase-specific antibodies will be assessed.
Number of Participants who Report Anti-idursulfase Antibodies in Serum
The presence of idursulfase-specific antibodies will be assessed.
Change From Baseline in Differential Ability Scales, Second Edition (DAS-II) Standard Scores and Standard Cluster Scores
The DAS-II will be used to assess all participants of age 2 years, 6 months or older. The DAS-II comprises 2 overlapping batteries. The Early Years battery is designed for children ages 2 years, 6 months through 6 years, 11 months. The Early Years battery is further divided into the Lower Level for children ages 2 years, 6 months through 3 years, 5 months and Upper Level for children ages 3 years 6 months through 6 years, 11 months. The School Age Battery is designed for children ages 7 years, 0 months through 17 years, 11 months. These batteries are fully co-normed for ages 5 years, 0 months, through 8 years, 11 months. The cluster areas include general conceptual ability (GCA), Verbal, Nonverbal, Spatial, and Special Nonverbal Composite (SNC). The cluster area score represents a score (mean = 100 and standard deviation of 15) on which higher scores indicate a higher level of cognitive ability.
Change From Baseline in Age Equivalent Scores of the Bayley Scales of Infant Development, Third Edition (BSID-III) Domains
Participants who are younger than 2 years, 6 months, will be assessed using the BSID-III. The BSID--III is a series of measurements to assess the motor (fine and gross), language (receptive and expressive), and cognitive development of infants and toddlers and consists of a series of developmental play tasks. Raw scores (range 40-160) will be converted to age- equivalent scores to measure ability, skill, and knowledge, expressed as the age at which most individuals reach the same level (age norm; range: 0, unbound).
Change From Baseline in Development Quotient (DQ) of the Bayley Scales of Infant Development, Third Edition (BSID-III) Domains
Participants who are younger than 2 years, 6 months, will be assessed using the BSID-III. The BSID--III is a series of measurements to assess the motor (fine and gross), language (receptive and expressive), and cognitive development of infants and toddlers and consists of a series of developmental play tasks. The development quotient (DQ) is a means to express a neurodevelopmental/cognitive delay which will be computed as a ratio and expressed as a percentage using the age equivalent score divided by the age at testing ([age-equivalent score/chronological age] × 100; range: 0-100).
Change From Baseline in Standard Scores of the Vineland Adaptive Behavior Scales, Second Edition (VABS-II) Domains
The VABS-II test measures adaptive behaviors, including the ability to cope with environmental changes, to learn new everyday skills, and to demonstrate independence. This test measures the following 4 key domains: communication, daily living skills, socialization, motor skills, and the adaptive behaviour composite (a composite of the other 4 domains). The standard scores represent a score (mean = 100 and standard deviation of 15) on which higher scores indicate a higher level of cognitive ability.
Change From Baseline in Standard Composite Scores of the Vineland Adaptive Behavior Scales, Second Edition (VABS-II) Domains
The VABS-II test measures adaptive behaviors, including the ability to cope with environmental changes, to learn new everyday skills, and to demonstrate independence. This test measures the following 4 key domains: communication, daily living skills, socialization, motor skills, and the adaptive behavior composite (a composite of the other 4 domains). The ABC score ranges from 20 to 160 on which higher scores indicate a higher level of adaptive functioning. A positive change value indicates improvement in adaptive functioning.
Change From Baseline in Age Equivalents Score of the Differential Ability Scales, Second Edition (DAS-II)
DAS-II will be used to assess all participants of age 2 years (Y), 6 months (M) or older. DAS-II comprises 2 overlapping batteries. Early Years Battery (EYB) is designed for ages 2Y,6M-6Y,11M. School Age Battery is designed for ages 7Y,0M-17Y,11M. These batteries are fully co-normed for age 5Y,0M-8Y,11M. Core subtests include Verbal (V) Comprehension, Picture Similarities, Naming Vocabulary, Pattern Construction (PC), Matrices (M) and Copying for DAS-II Early Y and Recall of Designs, Word Definitions, PC, M, Verbal Similarities, and Sequential and Quantitative Reasoning for DAS-II School Years. Standardized scores will be converted to age equivalent scores (AES) to measure ability, skill, and knowledge expressed as age at which most individuals reach same level. Mean AES will be obtained by averaging out AES. Higher score (HS) indicates greater cognitive ability (CA). Subtests score represent a score (mean=50 and standard deviation of 10) on which HS indicate a higher level of CA.
Change From Baseline in Developmental Quotients (DQ) of the Differential Ability Scales, Second Edition (DAS-II)
The DAS-II will be used to assess all participants of age 2 years (Y), 6 months (M) or older. The DAS-II comprises 2 overlapping batteries. The Early Years battery (EYB) is designed for children ages (CA) 2Y, 6M, through 6Y, 11M. The EYB is further divided into the Lower Level for CA 2Y, 6M through 3Y, 5M and Upper Level for CA 3Y, 6M through 6Y, 11M. The School Age Battery is designed for CA 7Y, 0M through 17Y, 1M. These batteries are fully co-normed for ages 5Y, 0M, through 8Y, 11M. The core subtests include Verbal Comprehension, Picture Similarities, Naming Vocabulary, Pattern Construction, Matrices, and Copying for the DAS-II Early Y and Recall of Designs, Word Definitions, Pattern Construction, Matrices, Verbal Similarities, and Sequential and Quantitative Reasoning for the DAS-II School Y. The DQ will be computed as a ratio and expressed as a percentage using the age equivalent score (AES) divided by the age at testing ([AES/chronological age] × 100; range, 0-100).
Change From Baseline in T-scores of the Core Subtests Differential Ability Scales, Second Edition (DAS-II)
The DAS-II will be used to assess all participants of age 2 years (Y), 6 months (M) or older. The DAS-II comprises 2 overlapping batteries. The Early Years battery (EYB) is designed for children ages (CA) 2Y, 6M, through 6Y, 11M. The EYB is further divided into the Lower Level for CA 2Y, 6M through 3Y, 5M and Upper Level for CA 3Y, 6M through 6Y, 11M. The School Age Battery is designed for CA 7Y, 0M through 17Y, 11M. These batteries are fully co-normed for ages 5Y, 0M, through 8Y, 11M. The core subtests (CS) include Verbal Comprehension, Picture Similarities, Naming Vocabulary, Pattern Construction, Matrices, and Copying for the DAS-II Early Years and Recall of Designs, Word Definitions, Pattern Construction, Matrices, Verbal Similarities, and Sequential and Quantitative Reasoning for the DAS-II School Years. The CS score represent a score (mean = 50 and standard deviation of 10) on which higher scores indicate a higher level of cognitive ability.
Change From Baseline in Age Equivalents Score of the Vineland Adaptive Behavior Scales, Second Edition (VABS-II) Sub Domains
The VABS-II test measures adaptive behaviors, including the ability to cope with environmental changes, to learn new everyday skills, and to demonstrate independence. This test measures the following subdomains of 5 key domains: Communication (Receptive, Expressive, Written), Daily Living Skills (Personal, Domestic, Community), Socialization (Interpersonal Relationships, Play and Leisure Time, Coping Skills), Motor Skills (Gross, Fine). The mean age equivalent score will be obtained by averaging out the age-equivalent scores for the all the sub-domains except for Gross and Fine motor skills (range: 0, unbound).
Change From Baseline in Developmental Quotients (DQ) of the Vineland Adaptive Behavior Scales, Second Edition (VABS-II) Sub Domains
The VABS-II test measures adaptive behaviors, including the ability to cope with environmental changes, to learn new everyday skills, and to demonstrate independence. This test measures the following subdomains of 5 key domains: Communication (Receptive, Expressive, Written), Daily Living Skills (Personal, Domestic, Community), Socialization (Interpersonal Relationships, Play and Leisure Time, Coping Skills), Motor Skills (Gross, Fine). The DQ will be computed as a ratio and expressed as a percentage using the age-equivalent score divided by the age at testing ([age-equivalent score/chronological age] × 100; range, 0-100).
Change From Baseline in v-Scores of the Vineland Adaptive Behavior Scales, Second Edition (VABS-II) Sub Domains
The VABS-II test measures adaptive behaviors, including the ability to cope with environmental changes, to learn new everyday skills, and to demonstrate independence. This test measures the following subdomains of 5 key domains: Communication (Receptive, Expressive, Written), Daily Living Skills (Personal, Domestic, Community), Socialization (Interpersonal Relationships, Play and Leisure Time, Coping Skills), Motor Skills (Gross, Fine). The V-scale scores represent a score (mean = 15 and standard deviation of 3; range: 1-24) on which higher scores indicate a higher level of adaptive functioning.
Change From Baseline in v-Scale Scores of the Vineland Adaptive Behavior Scales, Second Edition (VABS-II) Maladaptive Behavior Index and its Subscales
The VABS-II test measures adaptive behaviors, including the ability to cope with environmental changes, to learn new everyday skills, and to demonstrate independence. Maladaptive behavior index is a composite of the internalizing, externalizing, and other types of undesirable behavior that may interfere with the individual's adaptive functioning. The v-Scale scores represent a score (mean = 15 and standard deviation of 3; range: 1-24) on which higher scores indicate a higher level of adaptive functioning.
Change From Baseline in Observed Maladaptive Levels of the Vineland Adaptive Behavior Scales, Second Edition (VABS-II) Maladaptive Behavior Index and its Subscales
The VABS-II test measures adaptive behaviors, including the ability to cope with environmental changes, to learn new everyday skills, and to demonstrate independence. Maladaptive behavior index is a composite of the internalizing, externalizing, and other types of undesirable behavior that may interfere with the individual's adaptive functioning. The V scale scores represent a score (mean = 15 and standard deviation of 3; range: 1-24) on which higher scores indicate a higher level of cognitive ability.
Change From Baseline in Brain Structure Volume as Measured by Magnetic Resonance Imaging (MRI)
Brain structure volume will be assessed from brain total intracranial volume, brain total tissue volume, brain total white matter, brain total gray matter, and total CSF volume as measured by MRI.