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Active, Not Recruiting

NCT Number: NCT04348136

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

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

Active, Not Recruiting

This study is active but is not currently recruiting participants.

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Key information

Conditions

Mucopolysaccharidosis II Carbohydrate Metabolism, Inborn Errors Congenital, Hereditary, and Neonatal Diseases and Abnormalities Connective Tissue Diseases Genetic Diseases, Inborn Genetic Diseases, X-Linked Heredodegenerative Disorders, Nervous System Intellectual Disability Lysosomal Storage Diseases Metabolic Diseases Metabolism, Inborn Errors Mucinoses Mucopolysaccharidoses Nervous System Diseases Neurobehavioral Manifestations Neurologic Manifestations Nutritional and Metabolic Diseases Skin and Connective Tissue Diseases X-Linked Intellectual Disability

Sex eligibility

Male

Study type

Interventional

Phase

Phase 2 / Phase 3

Primary location

Fukui Clinical site, Fukui, Japan

Loading trial locations.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

JR-141

Drug

IV infusion, 2.0 mg/kg/week

Primary outcomes

  1. 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

  2. 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

  3. 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)

  4. 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)

  5. 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)

  6. Laboratory tests (urinalysis)

    Time frame: Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years

  7. Vital signs (pulse rate)

    Time frame: Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years

  8. Vital signs (body temperature)

    Time frame: Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years

  9. Vital signs (blood pressure)

    Time frame: Week 78, 104, an average of 52 weeks after Week 104, up to approximately 10.6 years

  10. 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)

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  21. 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

  22. 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

  23. 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

  24. 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

  25. 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

Sponsors and collaborators

Lead sponsor

JCR Pharmaceuticals Co., Ltd.

Industry

Registry information

Important dates

Study start
2019
Primary completion
2030
Study completion
2030
First posted
Apr 16, 2020
Registry last updated
Jul 24, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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