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

Study Overview
=================
Brief Summary
-----------------
Multicenter, open-label, single-group, designed to evaluate the long term efficacy and safety of study drug for the treatment of the MPS II.

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

Conditions
-----------------
Mucopolysaccharidosis II

Intervention / Treatment
-----------------
* Drug: JR-141


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: A patient who participated in the preceding Study JR-141-301 and completed the Week 52 visit, and has no safety concerns to enter this study in the opinion of the investigator or subinvestigator. A patient capable of providing written informed consent in person (However, this is not required for patients aged younger than 20 years at the time of consent or patients with intellectual disability associated with MPS II whose willingness cannot be verified.) For patients aged younger than 20 years at the time of consent or patients with intellectual disability associated with MPS II whose willingness cannot be verified, written consent must be obtained from the legally acceptable representative. (Wherever possible, written consent of the patient should be obtained.) Male patient whose partner is of child-bearing potential and agrees to use a medically accepted, highly effective method of contraception. Exclusion Criteria: A patient who used any concomitant medication or therapy that could affect study assessments in the opinion of the investigator or subinvestigator. A patient with a history of serious drug allergy or hypersensitivity that precludes participation in this study in the opinion of the investigator or subinvestigator. A patient judged to be ineligible by the investigator or subinvestigator for other reasons.
Sexes Eligible for Study
-----------------
Male

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

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> | Drug: JR-141<br>* IV infusion, 2.0 mg/kg/week<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Occurrence of adverse events |  | From the start of study (Week 52 of preceding study) up to the end of study, up to approximately 10.6 years | 
| Occurrence of adverse reactions |  | From the start of study (Week 52 of preceding study) up to the end of study, up to approximately 10.6 years | 
| Incidence of abnormal vital signs | Laboratory tests (hematology) | Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years | 
| Incidence of abnormal vital signs | Laboratory tests (biochemistry) | Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years | 
| Incidence of abnormal vital signs | Laboratory tests (iron-related tests) | Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years | 
| Laboratory tests (urinalysis) |  | Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years | 
| Vital signs (pulse rate) |  | Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years | 
| Vital signs (body temperature) |  | Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years | 
| Vital signs (blood pressure) |  | Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years | 
| 12-lead electrocardiogram | The presence or absence of abnormal findings (if present, specific findings and whether or not they are reported as adverse events) | Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years | 
| Antibody tests (anti-JR-141 antibodies) |  | Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years | 
| IAR |  | From the start of study (Week 52 of preceding study) up to the end of study, up to approximately 10.6 years | 
| Time course of developmental assessment data (Kyoto Scale of Psychological Development 2001) from initial dosing in the preceding study |  | Week 104, an average of 52 weeks after Week 104, up to approximately 10.6 years | 
| Time course of developmental assessment data (Vineland-II) from initial dosing in the preceding study |  | Week 104, an average of 52 weeks after Week 104, up to approximately 10.6 years | 
| Time course of developmental assessment data (Bayley-III or KABC-II) from initial dosing in the preceding study |  | Week 104, an average of 52 weeks after Week 104, up to approximately 10.6 years | 
| Time course of CSF substrate (HS and DS) concentrations from initial dosing in the preceding study |  | Week 104, an average of 52 weeks after Week 104, up to approximately 10.6 years | 
| Time course of serum HS and DS concentrations from initial dosing in the preceding study |  | Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years | 
| Time course of urinary HS concentration from initial dosing in the preceding study |  | Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years | 
| Time course of urinary DS concentration from initial dosing in the preceding study |  | Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years | 
| Time course of uronic acid concentration from initial dosing in the preceding study |  | Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years | 
| Time course of liver volume (assessed by CT or MRI) from initial dosing in the preceding study |  | Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years | 
| Time course of spleen volume (assessed by CT or MRI) from initial dosing in the preceding study |  | Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years | 
| Time course of cardiac function (assessed by echocardiography) from initial dosing in the preceding study |  | Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years | 
| Time course of 6-minute walk test distance from initial dosing in the preceding study |  | Week 104, an average of 52 weeks after Week 104, up to approximately 10.6 years | 
| Time course of joint range of motion from initial dosing in the preceding study |  | Week 104, an average of 52 weeks after Week 104, up to approximately 10.6 years |