The purpose of this study is to collect long-term safety data in participants with metachromatic leukodystrophy (MLD) who are receiving HGT-1110 and have participated in Study HGT-MLD-070 (NCT01510028) through Week 40.
MLD is an inherited, autosomal recessive disorder of lipid metabolism characterized by deficient activity of the lysosomal enzyme, arylsulfatase A (ASA). MLD is a rare orphan disease that occurs in most parts of the world. The estimated overall incidence of the disease in the western world is approximately 1 in 100,000 live births that varies by geographic location. There are no approved therapies for MLD. This study is a multicenter open-label study designed to evaluate safety and efficacy outcomes of HGT-1110 administered intrathecally in children with MLD who have participated in the dose escalation study, HGT-MLD-070 (NCT01510028), through Week 40 and are receiving study drug every other week (EOW). Treatment groups will be identical to those in HGT-MLD-070 (NCT01510028), ie, participants assigned to Cohort 1 in Study HGT-MLD-070 (NCT01510028) will continue to receive a dose of 10 milligrams (mg), participants assigned to Cohort 2 in Study HGT-MLD-070 (NCT01510028) will continue to receive a dose of 30 mg, and participants assigned to Cohorts 3 and 4 in Study HGT-MLD-070 (NCT01510028) will continue to receive a dose of 100 mg. Participants in Cohort 4 are to exclusively receive drug product produced with Process B in Study HGT-MLD-070 (NCT01510028) and will continue receiving this drug product in this study. Participants enrolled in this study from Cohorts 1 to 3 in Study HGT-MLD-070 (NCT01510028) were transitioned to Process B after all necessary approvals were obtained. In HGT-MLD-071, all participants in the 10 mg dose cohort who experienced disease progression, as determined by the Investigator, increased to the 30 mg dose after agreement by the Medical Monitor. Based on the interim analysis results from HGT-MLD-070 (NCT01510028 \[Cohorts 1-3\]), the dose of HGT-1110 will be increased to 100 mg for all participants in HGT-MLD-071 after all necessary approvals were obtained.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
24
Participants will receive IT injection of HGT-1110.
The Children's Hospital at Westmead
Westmead, Australia
Hospital de Clinicas de Porto Alegre
Porto Alegre, Brazil
Detska Interni Klinika, Lf Mu A Fn Brno
Brno, Czechia
Number of Participants With Treatment-Emergent Adverse Events (TEAEs)
An AE 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 drug product-related. TEAEs are defined as all AEs occurring or worsening at or after the first dose of investigational drug product in HGT-MLD-071 or ongoing from HGT-MLD-070 at the time of enrollment into HGT-MLD-071.
Time frame: Baseline to Follow-up (Week 628)
Presence of Anti-HGT-1110 Antibodies in Cerebrospinal Fluid (CSF) and Serum
The presence of anti-HGT-1110 antibodies in CSF and serum will be assessed.
Time frame: Baseline until end of the study (Week 624)
Change From Baseline in Motor Function as Assessed by Gross Motor Function Measure (GMFM-88) Total Score at Week 624
The GMFM-88 item scores can be used to calculate a domain-specific percent score for each of the 5 GMFM-88 dimensions, which are the following: Lying and rolling; Sitting; Crawling and kneeling; Standing; Walking, running, and jumping. Each of the 88 items is rated on a 4-point scale: 0=does not initiate; 1=initiates; 2=partially completes; and 3=completes. The GMFM-88 total scores range from 0% (no mobility) to a score of 100%, that is (i.e,) the score that can be obtained by an average 5-year-old or older child with normal motor abilities. The domain-specific percent scores are averaged to obtain the total score (percent).
Time frame: Baseline, Week 624
Change From Baseline in the Adaptive Behavior Composite Standard Score Measured by the Vineland Adaptive Behavior Scales, Second Edition (VABS-II)
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.
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Rigshospitalet
Copenhagen, Denmark
Hopital Femme Mere Enfant
Bron, France
Hopital Gui de Chauliac - CHRU de Montpellier
Montpellier, France
CHU de Nantes
Nantes, France
CHR Orleans - Hopital La Source
Orléans, France
Hôpital de Bicêtre
Le Kremlin-Bicêtre, Île-de-France Region, France
Center for Pediatric Clinical Studies (CPCS)
Tübingen, Baden-Wurttemberg, Germany
...and 5 more locations
Time frame: Baseline, Week 624
Change From Baseline in the Domain-Specific Caregiver Observed Metachromatic Leukodystrophy Functioning and Outcomes Reporting Tool (COMFORT) Scores
The COMFORT is a questionnaire that will be used to assess health status and the impact of disease on the ability of participants with MLD to carry out activities of daily life. The questionnaire is organized by 8 domains (that is, Personal Care, Positioning, Transfer or Mobility, Eating, Pain and Discomfort During the Day, Sleep, Emotions, Communication, Play and Leisure Activities) and will be completed by the participant's parent(s) or legal representative(s). It will be conducted in available validated languages. The COMFORT scores range from 0 to 100, with higher scores indicating a decline in the functioning.
Time frame: Baseline, Week 624
Maximum Observed Serum Concentration (Cmax) of HGT-1110
The Cmax of HGT-1110 will be assessed.
Time frame: Pre-dose, 0.5, 1, 2, 4, 8, 12, 24, and 48 hours post-dose on Weeks 104, 258, 364 and 622 in Cohort 4 and Week 8 in Cohorts 1-3
Time of Maximum Observed Serum Concentration (Tmax) of HGT-1110
The Tmax of HGT-1110 will be assessed.
Time frame: Pre-dose, 0.5, 1, 2, 4, 8, 12, 24, and 48 hours post-dose on Weeks 104, 258, 364 and 622 in Cohort 4 and Week 8 in Cohorts 1-3
Area Under the Serum Concentration-Time Curve From Time Zero to the Last Sampling Time at Which Serum Concentrations Were Measurable (AUC0-last) of HGT-1110
The AUC0-last of HGT-1110 will be assessed.
Time frame: Pre-dose, 0.5, 1, 2, 4, 8, 12, 24, and 48 hours post-dose on Weeks 104, 258, 364 and 622 in Cohort 4 and Week 8 in Cohorts 1-3
Area Under the Serum Concentration-Time Curve Extrapolated to Infinity (AUC0-inf) of HGT-1110
The AUC0-inf of HGT-1110 will be assessed.
Time frame: Pre-dose, 0.5, 1, 2, 4, 8, 12, 24, and 48 hours post-dose on Weeks 104, 258, 364 and 622 in Cohort 4 and Week 8 in Cohorts 1-3
Apparent Terminal Rate Constant (lambda z) of HGT-1110
The lambda z of HGT-1110 will be assessed.
Time frame: Pre-dose, 0.5, 1, 2, 4, 8, 12, 24, and 48 hours post-dose on Weeks 104, 258, 364 and 622 in Cohort 4 and Week 8 in Cohorts 1-3
Terminal Half-Life (t1/2) of HGT-1110
The t1/2 of HGT-1110 will be assessed.
Time frame: Pre-dose, 0.5, 1, 2, 4, 8, 12, 24, and 48 hours post-dose on Weeks 104, 258, 364 and 622 in Cohort 4 and Week 8 in Cohorts 1-3
Clearance (CL/F) of HGT-1110
The CL/F of HGT-1110 will be assessed.
Time frame: Pre-dose, 0.5, 1, 2, 4, 8, 12, 24, and 48 hours post-dose on Weeks 104, 258, 364 and 622 in Cohort 4 and Week 8 in Cohorts 1-3
Volume of Distribution (Vz/F) of HGT-1110
The Vz/F of HGT-1110 will be assessed.
Time frame: Pre-dose, 0.5, 1, 2, 4, 8, 12, 24, and 48 hours post-dose on Weeks 104, 258, 364 and 622 in Cohort 4 and Week 8 in Cohorts 1-3
Concentrations of HGT-1110 in Cerebrospinal Fluid (CSF)
Concentrations of HGT-1110 in CSF will be assessed.
Time frame: Baseline to End of the study (Week 624)