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A Phase I/II Trial of JR-446 in Mucopolysaccharidosis Type IIIB (MPS IIIB)

A Global, Open-Label, Phase I/II Trial, to Evaluate Safety, Tolerability, Pharmacodynamic and Preliminary Efficacy of JR-446 in Mucopolysaccharidosis Type IIIB (MPS IIIB)

Status
Not yet recruiting
Phases
Phase 1Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07640984
Enrollment
12
Registered
2026-06-11
Start date
2026-09-09
Completion date
2028-09-30
Last updated
2026-09-08

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Mucopolysaccharidosis IIIB

Brief summary

This is a global, open-label, Phase I/II, interventional trial in participants younger than 6 years of age with Mucopolysaccharidosis Type IIIB (MPS IIIB), designed to assess the safety and tolerability of JR-446, determine its pharmacodynamic effects, and explore its potential to demonstrate early clinical effects on disease-relevant outcomes.

Interventions

DRUGJR-446

IV infusion

Sponsors

JCR Pharmaceuticals Co., Ltd.
Lead SponsorINDUSTRY
MEDIPAL HOLDINGS CORPORATION
CollaboratorUNKNOWN

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
No minimum to 5 Years
Healthy volunteers
No

Inclusion criteria

1. Patients with confirmed MPS IIIB with a phenotype of MPS IIIB that is not classified as slowly progressive (i.e., not attenuated). 2. A chronological age \<6 years. 3. Ability to complete and achieve a Standard score ≥55, using either Bailey Scale of Infant Development-4 (BSID-4) Cognitive domain or Kaufman Assessment Battery for Children-II (KABC-II) Non-Verbal Index, whichever tool is most appropriate for the participant's chronological age.

Exclusion criteria

1. Contraindication for lumbar puncture or MRI. 2. A participant who has a medical condition or extenuating circumstance that, in the opinion of the principal investigator or sub-investigator, might compromise the participant's ability to comply with protocol requirements, the participant's well-being or safety, or the interpretability of the participant's clinical data. 3. A participant who has received any other investigational drug product (including but not limited to, tralesinidase alfa enzyme replacement therapy \[TA-ERT\], Genistein, KINERET \[anakinra\], ambroxol, miglustat) within 4 months (or 5 half-lives, whichever is longer) before the time of providing informed consent. 4. A participant who has received gene therapy treatment or hematopoietic stem cell transplantation (HSCT) with successful engraftment. 5. Serious drug allergy or hypersensitivity to any components of JR-446 or medications likely prescribed during the trial. 6. A participant has a history of bleeding disorder or current use of medications that, in the opinion of the investigator, place them at risk of bleeding following lumbar puncture. 7. A patient with recurrent epileptic seizures not adequately controlled with anti-seizure medication, and which, in the clinical judgment of the principal investigator, would preclude safe participation in the trial. 8. Serology consistent with human immunodeficiency virus (HIV) exposure or consistent with active hepatitis B (HepB) or hepatitis C (HepC) infection. 9. A participant/family, who, in the opinion of the investigator, may not be able to comply with protocol requirements and cooperate fully with the trial assessments, procedures, and scheduling for JR-446 IMP dose administrations. 10. Study participants for whom informed consent is unable to be provided by a parent or legal guardian; or when applicable for a study participant who is unable to provide assent with respect to study participation in conjunction with parental or legal guardian consent for participation on study. The above information is not intended to contain all considerations relevant to a patient's potential participation in this clinical trial.

Design outcomes

Primary

MeasureTime frameDescription
To establish the safety and tolerability of JR-446 in MPS IIIB patients following repeated dose administrationUp to 1 year (multiple visits)Incidence and severity of treatment-emergent adverse events; Incidence and severity of infusion-associated reactions; Incidence of clinically significant changes/abnormalities in safety laboratory tests, vital signs, and electrocardiogram.

Secondary

MeasureTime frame
Change From Baseline in Cerebrospinal Fluid Heparan Sulfate ConcentrationThrough Week 53 (up to 1 year; multiple visits)
Absolute Change From Baseline in Serum Heparan Sulfate ConcentrationThrough Week 53 (up to 1 year; multiple visits)
Percent Change From Baseline in Serum Heparan Sulfate ConcentrationThrough Week 53 (up to 1 year; multiple visits)
Absolute Change From Baseline in Urine Heparan Sulfate ConcentrationThrough Week 53 (up to 1 year; multiple visits)
Percent Change From Baseline in Urine Heparan Sulfate ConcentrationThrough Week 53 (up to 1 year; multiple visits)
Absolute Change From Baseline in Serum Neurofilament Light Chain ConcentrationThrough Week 53 (up to 1 year; multiple visits)
Percent Change From Baseline in Serum Neurofilament Light Chain ConcentrationThrough Week 53 (up to 1 year; multiple visits)
Change in Cognitive Function Assessments From BaselineThrough Week 53 (up to 1 year)
Change in Brain MRIs From BaselineThrough Week 53 (up to 1 year)
Change in Height Standard Deviation Score (SDS) From Baseline (using WHO child growth standards)Through Week 53 (up to 1 year)
Change in Weight SDS From Baseline (using WHO child growth standards)Through Week 53 (up to 1 year)
Change in Body Mass Index (BMI) SDS From Baseline (using WHO child growth standards)Through Week 53 (up to 1 year)

Countries

Germany, United Kingdom, United States

Contacts

CONTACTJCR Pharmaceuticals Co., Ltd.
clinical_development@jp.jcrpharm.com+81-797-32-8582

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Sep 9, 2026