An Extension Study of JR-141-BR21 in Patients With Mucopolysaccharidosis II

Study Overview
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Brief Summary
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A Phase II open-label, parallel group, 2 sites (Brazil), designed to evaluate the long term safety and efficacy of study drug for the treatment of the MPS II.

Official Title
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An Extension Study of JR-141-BR21 in Patients With Mucopolysaccharidosis II

Conditions
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Mucopolysaccharidosis II

Intervention / Treatment
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* Drug: JR-141


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients who will have completed clinical trial JR-141-BR21. Capable of providing written consent by himself, unless the patient is under the age of 18 years at the time of informed consent process, or it is not possible to obtain consent from the patient himself due to his intellectual disabilities associated with MPS II. In the case of a patient who is under the age of 18 years or from whom it is not possible to obtain consent due to his intellectual disabilities associated with MSP II, he may be included if written consent can be provided by legal representative; however written consent should be obtained from the patient himself too, wherever possible. Exclusion Criteria: Refusal to sign the informed consent form. Unable to perform the study procedures, except for neurocognitive testing. Previous engrafted BMT/HSCT. Judged by the investigator or subinvestigator as being unable to undergo lumbar puncture, including those who have difficulties in taking a position for lumber puncture due to joint contracture or those who are likely to experience difficulty breathing during the lumbar puncture process. Judged by the investigator or subinvestigator to be ineligible to participate in the study due to a history of a serious drug allergy or sensitivity. Otherwise judged by the investigator or subinvestigator to be ineligible to participate in the study out of consideration for the subject safety.

Ages Eligible for Study
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Minimum Age: 0 Years

Sexes Eligible for Study
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Male

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: JR-141<br>Subjects will be assigned to 1.0, 2.0 or 4.0 mg of JR-141 per kg of body weight once every week (the same dose taken during the previous study) in the beginning of the study. During the study, the dose of all subjects will be switched to the selected one*. * The dose was determined to be 2.0 mg/kg/week based on the safety and efficacy data of JR-141-BR21 study. | Drug: JR-141<br>* IV infusion (lyophilized powder)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of participants with Adverse Events |  | From screening up to the end of study, up to approximately 5 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Urinary heparan sulfate concentrations |  | through study completion, an average of 52 weeks, up to approximately 5 years | 
| Urinary dermatan sulfate concentrations |  | through study completion, an average of 52 weeks, up to approximately 5 years | 
| Serum heparan sulfate concentrations |  | through study completion, an average of 52 weeks, up to approximately 5 years | 
| Serum dermatan sulfate concentrations |  | through study completion, an average of 52 weeks, up to approximately 5 years | 
| Liver and spleen volumes (MRI) |  | through study completion, an average of 52 weeks, up to approximately 5 years | 
| Echocardiography |  | through study completion, an average of 52 weeks, up to approximately 5 years |