Effect of Enzyme Replacement Therapy in Patients With Juvenile-onset Pompe Disease

Study Overview
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Brief Summary
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Pompe disease is known as glycogen storage disease type II, an autosomal recessive disease that results from acid alpha-glucosidase (GAA) deficiency leading to lysosomal glycogen accumulation. Patients with classic infantile form have less than 1% of enzyme activity, which explains severe impairment before one year with rapid death without treatment, while later-onset form shows progressive symptoms later in childhood (juvenile form) or adulthood (adult form). Enzyme replacement therapy (ERT) consists of periodic intravenous infusion of missing GAA produced by the recombinant method. ERT improves significantly the cardiac function and the children's survival in classic infantile form. This therapy has been approved for all patients with Pompe's disease in the United States and the European Union since 2006, but its efficacy was not clear for patients with later-onset form. Recent studies show motor improvement in adult patients, but there is little published data for the juvenile form disease. A separate analysis of juvenile form is justified as patients are still in a developmental stage and show clinical symptoms early in life, may have more severe disease and a different response to ERT. The recommendation is no treatment in the absence of clinical symptoms, but the consensus does not stratify patients into juvenile- or adult-onset form. ERT is an expensive long-term therapy, and its administration every 2 weeks in the hospital is a great limitation for patients. Therefore, an evaluation of the treatment effect in patients with the juvenile form is necessary.

Detailed Description
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This study includes patients from several hospitals in france. The parameters allowing the evaluation of the respiratory and muscular function are collected.

Official Title
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Effect of Enzyme Replacement Therapy in Patients With Juvenile-Onset Pompe Disease: a Long-term Observational Study

Conditions
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Pompe's Disease Juvenile Onset

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: childhood Pompe disease (the first symptoms appear before 18 years old) follow-up in France Exclusion Criteria: infantile Pompe disease cardiomyopathy at diagnosis

Ages Eligible for Study
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Maximum Age: 18 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| French patients with juvenile Pompe disease<br>We aim to include all French patients with juvenile Pompe disease (maltase acid deficiency without cardiomyopathy) | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 6-min walk test | Walking distance during 6 minutes | Day 1 | 
| 6-min walk test | Walking distance during 6 minutes | Through study completion, an average of 1 year | 
| Forced vital capacity | Evaluation of respiratory function test | Day 1 | 
| Forced vital capacity | Evaluation of respiratory function test | Through study completion, an average of 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Blood creatinine kinase level | Biological marker of Pompe disease | Day 1 | 
| Blood creatinine kinase level | Biological marker of Pompe disease | Through study completion, an average of 1 year | 
| ASAT | Biological markers of tPompe Disease | Day 1 | 
| ASAT | Biological markers of tPompe Disease | Through study completion, an average of 1 year | 
| ALAT | Biological markers of tPompe Disease | Day 1 | 
| ALAT | Biological markers of tPompe Disease | Through study completion, an average of 1 year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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no cardiomyopathy at diagnosis