Sanfilippo syndrome Type A, or Mucopolysaccharidosis (MPS) IIIA, is a rare lysosomal storage disease caused by deficiency of the enzyme heparan N-sulfatase (sulfamidase). In the absence of this enzyme, there is an accumulation of the glycosaminoglycan, heparan sulfate, resulting in progressive neurodegeneration. Symptoms are usually first noted in the 1st or 2nd year of life, although definitive diagnosis is often delayed, with an average age of diagnosis of 4.5 years. The disease is characterized by developmental delays initially, followed by neurological developmental arrest, then regression. These developmental deficits are typically associated with severe behavioral disturbances. Patients have a significantly reduced lifespan, with few surviving beyond the 2nd or 3rd decade. The purpose of this study is to evaluate the safety and efficacy of recombinant human heparan-N-sulfatase (rhHNS) in pediatric patients with Early Stage Mucopolysaccharidosis Type III A Disease.
No effective, disease-modifying therapies are currently approved as treatments for this devastating and disabling disease. Shire Human Genetic Therapies (Shire HGT) is developing an enzyme replacement therapy (ERT) recombinant human heparan-N-sulfatase (rhHNS) for patients with MPS IIIA. rhHNS is being administered into the cerebrospinal fluid (CSF) via an surgically implanted intrathecal drug delivery device (IDDD), because when administered intravenously (IV) it does not cross the blood brain barrier (BBB). This study will evaluate the effect of 48 weeks of rhHNS treatment on the clinical course of MPS IIIA, using cognitive function as the primary outcome measure. The trial will evaluate 2 dosing regimens of rhHNS administered via an IDDD in comparison with a no treatment control group. Patients will be randomized 1:1:1 to either of the treatment groups or the no treatment group. Treatment will be administered in an open-label manner. The safety and tolerability profile of rhHNS will continue to be evaluated in this study.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
21
Recombinant human heparan N-sulfatase \[rhHNS\]
Los Angeles Biomedical Research
Torrance, California, United States
University of Minnesota Department of Pediatrics
Minneapolis, Minnesota, United States
University of North Carolina
Chapel Hill, North Carolina, United States
Hospital Universitario Austral A Unidad de Investigacion
Buenos Aires, Argentina
Chu Bicetre
Le Kremlin-Bicêtre, Paris, France
Universitätsklinikum Hamburg Eppendorf
Hamburg, Germany
U.O.S Malattie Metaboliche Rare Clinical Pediatrica
Monza, Italy
Academisch Medisch Centrum
Amsterdam, Netherlands
Hospital Vall D'Hebron
Barcelona, Spain
Great Ormond Street Hospital
London, United Kingdom
Number of Participants With Overall Response Using Bayley Scales of Infant Development Assessment Third Edition (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 was 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). The BSID--III DQ score is based on the cognitive domain. A positive value indicates improvement in health and cognition. Overall response was the maximum decline in the DQ of 10 points or less over 48 weeks. Number of participants with the overall response were reported here.
Time frame: Baseline (Week 0) up to Week 48
Number of Participants With Serious Adverse Events (SAE)
An adverse event (AE) was 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. This included an exacerbation of a pre-existing condition. 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; lifethreatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly.
Time frame: Baseline (Week 0) up to Week 52
Number of Participants With Treatment Emergent Adverse Events (TEAEs)
An adverse event (AE) was 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. This included an exacerbation of a pre-existing condition. TEAEs were defined as AE occurring on or after the time of first IDDD implantation or LP procedure to the end of study (EOS) visit (+30 days).
Time frame: Baseline (Week 0) up to Week 52
Number of Participants With Positive Anti-recombinant Human Heparan-N-Sulfatase (rhHNS) Antibody in Serum at Week 48
A participant was considered positive if they had at least 1 positive result during the study. Once a participant reported antibody positive, they were considered positive for the remainder of the study.
Time frame: Baseline (Week 0) up to Week 48
Change From Baseline in Vineland Adaptive Behavior Scales Second Edition (VABS-II) Development Quotient (DQ) Score at Week 48
The VABS-II test measures adaptive behaviors, including the ability to cope with environmental changes, to learn new everyday skills, and to demonstrate independence. The DQ is a means to express a neurodevelopmental/cognitive delay. The DQ was 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). The overall DQ score is calculated from the mean age-equivalent score obtained by averaging out the age-equivalent scores for the all the sub-domains except for Gross and Fine motor skills. This test measures the following 5 key domains: communication, daily living skills, socialization, motor skills, and the adaptive behavior composite (a composite of the other 4 domains). A positive value indicates improvement in health and cognition.
Time frame: Baseline (Week 0), Week 48
Change From Baseline in Development Quotient (DQ) Using Bayley Scales of Infant Development Assessment Third Edition (BSID-III) at Week 48
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 DQ is a means to express a neurodevelopmental/cognitive delay which was 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). The BSID--III DQ score is based on the cognitive domain. A positive value indicates improvement in health and cognition.
Time frame: Baseline (Week 0), Week 48
Change From Baseline in Total Cortical Grey Matter Volume at Week 48
The change from baseline in grey matter volume at Week 48 was assessed by magnetic resonance imaging (MRI).
Time frame: Baseline (Week 0), Week 48
Change From Baseline in Concentration of Glycosaminoglycan (GAG) in Cerebrospinal Fluid (CSF) at Week 48
Change from baseline in concentration of GAG in CSF at Week 48 was reported.
Time frame: Baseline (Week 0), Week 48
Change From Baseline in Concentration of GAG in Urine at Week 48
The concentration of GAG in urine was normalized to the urine creatinine value and reported as milligram (mg) GAG per millimole (mmol) creatinine.
Time frame: Baseline (Week 0), Week 48
Concentration of Recombinant Human Heparan-N-Sulfatase (rhHNS) in Cerebrospinal Fluid (CSF)
Concentration of rhHNS in CSF was assessed using validated enzyme-linked immunosorbent assay (ELISA) method.
Time frame: Pre-dose, 4, 48 hours on Week 0 and Week 48
Maximum Observed Drug Concentration (Cmax) of Recombinant Human Heparan-N-Sulfatase (rhHNS) in Serum
Cmax of rhHNS in serum was evaluated using enzyme-linked immunosorbent assay (ELISA) method and liquid chromatography tandem mass spectrometry (LC-MS) method.
Time frame: Predose, 0.5 h, 1 h, 2 h, 4 h, 8 h, 12 h, 24 h, and 48 h post-dose on Week 0 and Week 48
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.