A Phase III Study of JR-141 in Patients With Mucopolysaccharidosis II (STARLIGHT)

NCT04573023 | Active Not Recruiting Phase 3 DMC FDA Drug

• 1 other identifier: JR-141-GS31
• Study Type: interventional
• Target: 86
• Locations: 12 countries
• Sites: 24

Brief Summary

A Global Phase III multicenter, randomized, assessor-blinded, active-controlled designed to evaluate safety and efficacy of study drug for the treatment of the MPS II.

Conditions

Mucopolysaccharidosis II

Outcome Measures

Primary Outcomes (2)

• Change in levels of cerebrospinal fluid heparan sulfate from baseline (Cohort A)

  Baseline to Week 53

• Change in the raw scores of cognitive testing measured from baseline (BSID-III) (Cohort A)

  Baseline to Week 105

Secondary Outcomes (5)

• For regions other than US: Change in the age equivalent scores of cognitive testing measured from baseline (BSID-III or KABC-II) (Cohort A)

  Baseline to Week 105

• For regions other than US: Change in the age equivalent scores of adaptive behavior measured from baseline (VABS-II) (Cohort A)

  Baseline to Week 105

• For the US: Change in the raw scores of adaptive behavior measured from baseline (VABS-II) (Cohort A)

  Baseline to Week 105

• For all regions: Relative change in liver volume relative to body weight from baseline (Cohort A and Cohort B)

  Baseline to Week 53

• For all regions: Relative change in spleen volume relative to body weight from baseline (Cohort A and Cohort B)

  Baseline to Week 53

Study Arms (3)

JR-141 2.0 mg/kg/week

EXPERIMENTAL

Drug: JR-141

administered as the standard of care: idursulfase (ELAPRASE®)

OTHER

standard of care-controlled study

Drug: Idursulfase

Rescue arm

OTHER

Drug: JR-141 or Idursulfase

Interventions

JR-141 DRUG

IV infusion, 2.0 mg/kg/week

JR-141 2.0 mg/kg/week

Idursulfase DRUG

IV infusion

administered as the standard of care: idursulfase (ELAPRASE®)

JR-141 or Idursulfase DRUG

The subjects who have achieved the pre-specified criteria\* are able to change the drug. \*If a subject in Idursulfase group shows decline in their neurocognitive outcome, idursulfase can be switched to JR-141. If a subject in JR-141 group shows decline in their peripheral outcome, JR-141 will be switched to idursulfase.

Rescue arm

Eligibility Criteria

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

You may qualify if:

• A patient who voluntarily signs an Institutional Review Board or Independent Ethics Committee-approved written informed consent form. If the patient is aged under 18 years (aged under 16 years in the UK) at the time of enrollment or willingness to participate in the study cannot be confirmed due to MPS II-related intellectual disability, the patient's legally acceptable representative (e.g., his/her parents or guardians) may sign the informed consent on behalf of the patient. Written informed assent should be obtained from the patient, wherever possible.
• Patients with confirmed diagnosis of MPS II
• Naïve patients or patients who are receiving stable enzyme replacement therapy with idursulfase for more than 12 weeks before starting administration of JR-141 or idursulfase for this study.
• Patients or patients whose partners are of child-bearing potential agree to use a medically accepted, highly effective method of contraception being use of condoms from the time of informed consent.
• \<Cohort A\>
• Patients aged 36-42 months old at the time of ICF signing: patients must have a standard score measured by the BSID-III of 85 or less at screening.
• Patients aged 43-71 months old at the time of ICF signing: patients must EITHER have (1) A DQ measured by BSID-III of 20 to 85 at screening OR (2) A composite standard score on NVI measured by KABC-II of 85 or less at screening (only who can perform KABC-II)
• Patients aged 30-35 months old at the time of randomization and who are judged as having the severe phenotype by the Expert Board.
• \<Cohort B\>
• Patients 6 years of age or older at the time of ICF signing and whose IQ are 70 and higher.
• Enrollment of subjects in Cohort B is contingent on the availability in that country of a validated country-specific version of the test (either WISC-V, WAIS-IV, or T.O.V.A.).
• Attenuated patients with 1 SD deficiency in the omission errors or variability domains of the T.O.V.A..
• Patients or patients whose female partners are of child-bearing potential i.e., fertile, following menarche and until becoming post-menopausal unless permanently sterile, agree to use a medically accepted, highly effective method of contraception, from the time of informed consent. The method of contraception must be used during the study until 90 days for male subjects, and 30 days for female subjects after the final study intervention administration.
• For subjects with hearing impairment requiring hearing aid(s), every effort has been made to encourage compliance with the use of functioning hearing aid(s) before baseline neurocognitive assessments, and parent/legally acceptable representative or subject agrees to encourage wearing them during the study and on neurocognitive testing days.

You may not qualify if:

• A patient with a history of HSCT with successful engraftment.
• A patient who has received gene therapy treatment at any point.
• A patient who is judged by the principal investigator or sub-investigator as being unable to undergo lumbar puncture, including those who have difficulties in taking position for lumbar puncture due to joint contracture or those who are likely to experience breathing difficulties during the lumbar puncture process.
• A patient who is enrolled in another clinical study that involves clinical investigations or use of any investigational product (drug or device) within 4 months before obtaining informed consent.
• Unable to comply with the protocol as determined by the principal investigator or subinvestigator.
• Judged by the principal investigator or subinvestigator to be ineligible to participate in the study due to a history of serious drug allergy or sensitivity including anesthesia or hypersensitivity to any component of JR-141.
• A patient who has a known or suspected local or general infection or is at risk of abnormal bleeding due to medical conditions or therapies.
• A patient who has documented mutation of other genes, including loci adjacent to the IDS gene that are known to be associated with developmental delay, seizures, or other significant CNS disorders.
• A patient who has documented loss of activity of sulfatases other than IDS.
• A patient who has had a ventriculoperitoneal shunt placed or any other brain surgery, or has a clinically significant ventriculoperitoneal shunt malfunction within 30 days of screening.
• A patient who is full time employee of the sponsor or research site personnel directly affiliated with this study or their immediate family members.
• A patient who otherwise is judged by the principle investigator or sub-investigator to be ineligible to participate in the study.
• The subject has a positive pregnancy test or is breastfeeding at screening or randomization.
• \[Only in France\]
• Persons deprived of their liberty by a judicial or administrative decision, according to article L.1121-6 the Public Health Code (Code de la santé publique), adults who are the subject of a measure of legal protection or unable to express their consent according to article L. 1121-8 of the Code de la santé publique)

Sponsors & Collaborators

• JCR Pharmaceuticals Co., Ltd.: lead

Study Sites (24)

Phoenix Children's Hospital

Phoenix, Arizona, 27599-7487, United States

Location

UCSF Benioff Children's Hospital Oakland

Oakland, California, 94609, United States

Location

Ann & Robert H. Lurie Children's Hospital of Chicago

Chicago, Illinois, 60611, United States

Location

University of Minnesota

Minneapolis, Minnesota, 55455, United States

Location

Columbia University

New York, New York, 10032, United States

Location

University of North Carolina at Chapel Hill Medical School Wing E

Chapel Hill, North Carolina, 27599-7487, United States

Location

Children's Hospital of Philadelphia

Philadelphia, Pennsylvania, 19104, United States

Location

Hospital Universitario Austral

Buenos Aires, Argentina

Location

Hospital de Clínicas de Porto Alegre

Porto Alegre, Brazil

Location

Instituto de Genética e Erros Inatos do Metabolismo

São Paulo, Brazil

Location

Fundación Cardio Infantil - Instituto de Cardiología

Bogotá, Colombia

Location

Hôpital Femme Mère Enfant

Bron, France

Location

Hôpital Armand Trousseau

Paris, France

Location

Universitätsklinikum Giessen

Giessen, Germany

Location

Universitätsklinikum Hamburg-Eppendorf

Hamburg, Germany

Location

SphinCS GmbH

Höchheim, Germany

Location

Universitätsmedizin Mainz

Mainz, Germany

Location

Ha'Emek Medical Center

Afula, Israel

Location

Osp. Pediatrico Bambino Gesù, IRCCS

Rome, Italy

Location

Uniwersytecki Szpital Dziecięcy

Krakow, Poland

Location

Hospital Sant Joan de Déu

Barcelona, Spain

Location

Gazi University Medicine Faculty Hospital

Ankara, Turkey (Türkiye)

Location

Ege University Children Hospital

Izmir, Turkey (Türkiye)

Location

Great Ormond Street Hospital for Children NHS Trust - Metabolic Medicine

London, United Kingdom

Location

MeSH Terms

Conditions

Mucopolysaccharidosis II

Interventions

idursulfase

Condition Hierarchy (Ancestors)

X-Linked Intellectual Disability; Intellectual Disability; Neurobehavioral Manifestations; Neurologic Manifestations; Nervous System Diseases; Genetic Diseases, X-Linked; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Heredodegenerative Disorders, Nervous System; Mucopolysaccharidoses; Carbohydrate Metabolism, Inborn Errors; Metabolism, Inborn Errors; 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 3
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: September 17, 2020
• First Posted: October 5, 2020
• Study Start: February 14, 2022
• Primary Completion (Estimated): October 31, 2027
• Study Completion (Estimated): October 31, 2027
• Last Updated: April 21, 2026

Record last verified: 2026-04

Locations

FR (2); PL (1); GB (1); DE (4); AR (1); US (7); TU (2); BR (2); IT (1); ES (1); IL (1); CO (1)