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

July 21, 2025 updated by: JCR Pharmaceuticals Co., Ltd.
Multicenter, open-label, single-group, designed to evaluate the long term efficacy and safety of study drug for the treatment of the MPS II.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
27

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2
  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Japan
      • Fukui, Japan, 910-1193
        • Fukui Clinical site
      • Fukuoka, Japan, 813-0017
        • Fukuoka Clinical site 2
      • Fukuoka, Japan, 830-0011
        • Fukuoka Clinical site
      • Gifu, Japan, 501-1194
        • Gifu Clinical site
      • Hiroshima, Japan, 734-8530
        • Hiroshima Prefectural Hospital
      • Hokkaido, Japan, 063-0005
        • Hokkaido Clinical site
      • Kanagawa, Japan, 232-8555
        • Kananagawa Ckinical site
      • Kumamoto, Japan, 860-8556
        • Kumamoto Clinical site
      • Okayama, Japan, 701-1192
        • Okayama Clinical site
      • Okayama, Japan, 710-8602
        • Okayama Clinical site 2
      • Okinawa, Japan, 903-0215
        • Okinawa Clinical site
      • Osaka, Japan, 534-0021
        • Osaka Clinical site 3
      • Osaka, Japan, 545-8586
        • Osaka Clinical site 2
      • Osaka, Japan, 565-0871
        • Osaka Clinical site
      • Saitama, Japan, 330-8777
        • Saitama Clinical site
      • Shizuoka, Japan, 420-8660
        • Shizuoka Clinical site
      • Shizuoka, Japan, 426-8677
        • Shizuoka Clinical site 2
      • Tochigi, Japan, 329-0498
        • Tochigi Clinical site
      • Tokyo, Japan, 157-8535
        • Tokyo Clinical site
      • Tottori, Japan, 683-8504
        • Tottori Clinical site

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. 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.
  2. 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.)
  3. 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.)
  4. Male patient whose partner is of child-bearing potential and agrees to use a medically accepted, highly effective method of contraception.

Exclusion Criteria:

  1. A patient who used any concomitant medication or therapy that could affect study assessments in the opinion of the investigator or subinvestigator.
  2. 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.
  3. A patient judged to be ineligible by the investigator or subinvestigator for other reasons.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: JR-141
Drug: JR-141
IV infusion, 2.0 mg/kg/week

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Occurrence of adverse events
Time Frame: From the start of study (Week 52 of preceding study) up to the end of study, up to approximately 10.6 years
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
Time Frame: From the start of study (Week 52 of preceding study) up to the end of study, up to approximately 10.6 years
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
Time Frame: Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years
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
Time Frame: Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years
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
Time Frame: Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years
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)
Time Frame: Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years
Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years
Vital signs (pulse rate)
Time Frame: Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years
Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years
Vital signs (body temperature)
Time Frame: Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years
Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years
Vital signs (blood pressure)
Time Frame: Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years
Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years
12-lead electrocardiogram
Time Frame: Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years
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)
Time Frame: Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years
Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years
IAR
Time Frame: From the start of study (Week 52 of preceding study) up to the end of study, up to approximately 10.6 years
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
Time Frame: Week 104, an average of 52 weeks after Week 104, up to approximately 10.6 years
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
Time Frame: Week 104, an average of 52 weeks after Week 104, up to approximately 10.6 years
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
Time Frame: Week 104, an average of 52 weeks after Week 104, up to approximately 10.6 years
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
Time Frame: Week 104, an average of 52 weeks after Week 104, up to approximately 10.6 years
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
Time Frame: Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years
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
Time Frame: Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years
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
Time Frame: Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years
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
Time Frame: Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years
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
Time Frame: Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years
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
Time Frame: Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years
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
Time Frame: Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years
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
Time Frame: Week 104, an average of 52 weeks after Week 104, up to approximately 10.6 years
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
Time Frame: Week 104, an average of 52 weeks after Week 104, up to approximately 10.6 years
Week 104, an average of 52 weeks after Week 104, up to approximately 10.6 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
JCR Pharmaceuticals Co., Ltd.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 1, 2019

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
March 31, 2030

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
March 31, 2030

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
December 18, 2019

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 13, 2020

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 16, 2020

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
July 24, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 21, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • JR-141-302

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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