An Extension Study of JR-171-101 Study in Patients With Mucopolysaccharidosis Type I (MPS I)

NCT04453085 | Completed Phase 1 DMC FDA Drug

• 1 other identifier: JR-171-102
• Study Type: interventional
• Target: 14
• Locations: 3 countries
• Sites: 6

Brief Summary

Phase I/II, open label, multicenter, multinational (Japan, Brazil and the US) extension study of JR-171-101 (NCT04227600) for the treatment of MPS I

Conditions

Mucopolysaccharidosis I

Keywords

Mucopolysaccharidosis I

Outcome Measures

Primary Outcomes (13)

• Number of participants with Adverse Events

  Adverse events

  156 weeks

• Incidence of abnormal laboratory test results

  Hematology

  156 weeks

• Incidence of abnormal laboratory test results

  Biochemistry

  156 weeks

• Incidence of abnormal laboratory test results

  Serum iron tests

  156 weeks

• Incidence of abnormal laboratory test results

  Urinalysis

  156 weeks

• Incidence of abnormal vital signs

  Pulse rate

  156 weeks

• Incidence of abnormal vital signs

  Body temperature

  156 weeks

• Incidence of abnormal vital signs

  Blood pressure

  156 weeks

• Incidence of abnormal vital signs

  Body weight

  156 weeks

• Incidence of abnormal EKG readings

  156 weeks

• Number of participants with Adverse Events

  Anti-human-α-L-iduronidase antibodies

  156 weeks

• Number of participants with Adverse Events

  Anti-JR-171 antibodies

  156 weeks

• Number of participants with Adverse Events

  Infusion associated reaction (IAR)

  156 weeks

Secondary Outcomes (22)

• Change From Baseline in Heparan Sulfate Levels in Cerebrospinal Fluid (CSF)

  Weeks 26, 52, 104, 156

• Change From Baseline in Dermatan Sulfate Levels in Cerebrospinal Fluid

  Weeks 26, 52, 104, 156

• CSF opening pressure

  Weeks 26, 52, 104, 156

• Change From Baseline in Heparan Sulfate Levels in Urinary

  Weeks 13, 26, 39, 52, 65, 78, 91, 104, 130, 156

• Change From Baseline in Dermatan Sulfate Levels in Urinary

  Weeks 13, 26, 39, 52, 65, 78, 91, 104, 130, 156

Study Arms (2)

Dose level 1

EXPERIMENTAL

2.0 mg/kg/week

Drug: JR-171

Dose level 2

EXPERIMENTAL

4.0 mg/kg/week

Drug: JR-171

Interventions

JR-171 DRUG

Intravenous (IV) infusion

Also known as: lepunafusp alfa

Dose level 1; Dose level 2

Eligibility Criteria

• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• Patients who have completed the Part 2 of JR-171-101 study
• A patient from whom written informed consent can be obtained. If the patient is aged under 18 years (20 years in case of Japan) at the time of assent or willingness to participate in the study cannot be confirmed due to MPS I-related intellectual disability, informed permission from the patient's legally acceptable representative (e.g., his/her parents or guardians) need to be obtained instead of his/her consent. Even in this case, written informed consent should be obtained from the patient, wherever possible
• Female patient or male patient whose co-partners is of child-bearing potential agree to use a medically accepted, highly effective method of contraception, such as spermatocidal gel plus condom, an intrauterine device or oral contraceptives until one month after the final administration.

You may not qualify if:

• A patient who is unable to perform the study procedures, except for 6-minute walk test, neurocognitive testing, BVMT-R, HVLT-R, and T.O.V.A.
• Judged by the principal investigator or subinvestigator as being unable to undergo lumbar puncture, including those who have difficulties in taking a position for lumbar puncture due to joint contracture or those who are likely to experience difficulty breathing during the lumbar puncture process
• Judged by the principal investigator or subinvestigator to be ineligible to participate in the study due to a history of a serious drug allergy or hypersensitivity to any drugs
• Otherwise judged by the principal investigator or subinvestigator to be ineligible to participate in the study in consideration of patient's safety

Sponsors & Collaborators

• JCR Pharmaceuticals Co., Ltd.: lead

Study Sites (6)

UCSF Benioff Children's Hospital Oakland

Oakland, California, 94609, United States

Location

Hospital de Clínicas de Porto Alegre

Porto Alegre, Brazil

Location

Instituto de Genética e Erros Inatos do Metabolismo - IGEIM

São Paulo, Brazil

Location

Fukuoka Children's Hospital

Fukuoka, Japan

Location

National Hospital Organization Kokura Medical Center

Kitakyushu, Japan

Location

Osaka Metropolitan University Hospital

Osaka, Japan

Location

MeSH Terms

Conditions

Mucopolysaccharidosis I

Condition Hierarchy (Ancestors)

Mucopolysaccharidoses; Carbohydrate Metabolism, Inborn Errors; Metabolism, Inborn Errors; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Lysosomal Storage Diseases; Mucinoses; Connective Tissue Diseases; Skin and Connective Tissue Diseases; Metabolic Diseases; Nutritional and Metabolic Diseases

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: June 4, 2020
• First Posted: July 1, 2020
• Study Start: October 28, 2021
• Primary Completion: May 2, 2025
• Study Completion: May 2, 2025
• Last Updated: August 28, 2025

Record last verified: 2025-08

Data Sharing

• IPD Sharing: Will not share

Locations

US (1); JP (3); BR (2)