Extension Study of Protocol ENB-006-09 - Study of Asfotase Alfa in Children With Hypophosphatasia (HPP)

Study Overview
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Brief Summary
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This clinical trial studies the long term safety and efficacy of asfotase alfa in children with HPP who completed Study ENB-006-09 (NCT00952484).

Detailed Description
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Asfotase alfa was formerly referred to as ENB-0040 Hypophosphatasia (HPP) is a life-threatening, genetic, and ultra-rare metabolic disease characterized by defective bone mineralization and impaired phosphate and calcium regulation that can lead to progressive damage to multiple vital organs, including destruction and deformity of bones, profound muscle weakness, seizures, impaired renal function, and respiratory failure. There are limited data available on the natural course of this disease over time, particularly in patients with the juvenile-onset form.

Official Title
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Extension Study of Protocol ENB-006-09 Evaluating the Long-term Safety and Efficacy of Asfotase Alfa (Human Recombinant Tissue Nonspecific Alkaline Phosphatase Fusion Protein) in Children With Hypophosphatasia (HPP)

Conditions
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Hypophosphatasia (HPP)

Intervention / Treatment
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* Biological: Asfotase Alfa


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Compliant and satisfactory completion of Enobia-sponsored clinical trial ENB-006-09 Written informed consent by parent or other legal guardian prior to any study procedures being performed Parent or other legal guardian willing to comply with study requirements Exclusion Criteria: Clinically significant disease that precludes study participation, in the Investigator's opinion Treatment with an investigational drug other than asfotase alfa Enrollment in any study (other than ENB-006-09) involving an investigational drug, device, or treatment for HPP Prior treatment with bisphosphonates

Ages Eligible for Study
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Minimum Age: 5 Years
Maximum Age: 12 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: asfotase alfa<br>asfotase alfa starting dose 3 mg/kg/week SC injection, increased to 6 mg/kg/week SC injection | Biological: Asfotase Alfa<br> <br> * Other names: human recombinant tissue nonspecific alkaline phosphatase fusion protein;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Skeletal Radiograph Evaluation Using a Qualitative Radiographic Global Impression of Change (RGI-C) Scale Compared to Baseline (Pre-treatment) in Study ENB-006-09. | Evaluation of radiographic change in rickets severity (as assessed by skeletal radiographs of the hands/wrists and knees) from the Baseline of Study ENB-006-09 (NCT00952484) to the End of Study (EOS) visit in Study ENB-008-10 using an ordinal RGI-C scale score. The RGI-C is a 7-point rating scale that ranges from -3 (indicative of severe worsening of HPP associated rickets) to +3 (indicative of complete or near complete healing of HPP associated rickets). The time points will be pre-treatment (Baseline from Study ENB-006-09) to the last radiographic assessment in Study ENB-008-10, which represents at least 72 months of treatment. | At least 72 months of treatment with asfotase alfa | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Hypophosphatasia, HPP, Bone Disease, Soft Bones, Low Alkaline Phosphatase, genetic metabolic disorder, alkaline phosphatase, tissue non-specific alkaline phosphatase, rickets, osteomalacia