Mucopolysaccharidosis IIIBPhase 1/2NCT07640984
A Phase I/II Trial of JR-446 in Mucopolysaccharidosis Type IIIB (MPS IIIB)
A Phase 1/2 study testing JR-446 in people with Mucopolysaccharidosis IIIB, run by JCR Pharmaceuticals Co., Ltd. at 5 sites in 3 countries.
Trial 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… Read more about this study
- Who is it for?
- Ages Up to 5 years
- Conditions the study is for
- Mucopolysaccharidosis IIIB
- What is being tested?
- JR-446
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 12 participants
- Where
- 5 sitesin 3 countries
- Study dates
- 9 Sep 2026to 30 Sep 2028
- Phase
- Phase 1/2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages Up to 5 years
- All sexes
- No healthy volunteers
- Child
Who may be able to join
- Patients with confirmed MPS IIIB with a phenotype of MPS IIIB that is not classified as slowly progressive (i.e., not attenuated).
- A chronological age <6 years.
- 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.
Who cannot join
- Contraindication for lumbar puncture or MRI.
- 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.
- 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.
- A participant who has received gene therapy treatment or hematopoietic stem cell transplantation (HSCT) with successful engraftment.
- Serious drug allergy or hypersensitivity to any components of JR-446 or medications likely prescribed during the trial.
- 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.
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- 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.
- Serology consistent with human immunodeficiency virus (HIV) exposure or consistent with active hepatitis B (HepB) or hepatitis C (HepC) infection.
- 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.
- 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.
Trial locations and contacts
5 sites in 3 countries. Contact the study team or a site near you to ask about taking part.
5 sites in 3 countries
United States3 sites, 3 recruiting
- Not yet recruiting
Lysosomal and Rare Disorders Research and Treatment Center (LDRTC)
Fairfax, Virginia, 22030
Ozlem Goker-Alpan, 703-261-6220, ogoker-alpan@ldrtc.org
- Recruiting
Children's Hospital Oakland Research Institution, Attn: 2900 Wing
Oakland, California, 94609
Irene Chang, 415-476-2757, Irene.chang@ucsf.edu
- Not yet recruiting
UPMC Children's Hospital of Pittsburgh
Pittsburgh, Pennsylvania, 15224
Deepa Rajan, 412-692-6787, rajands@upmc.edu
Germany1 site, 1 recruiting
- Not yet recruiting
University Medical Center Hamburg-Eppendorf
Hamburg, 20246
Nicole Maria Muschol, +49 (0) 40 7410 53714, muschol@uke.de
United Kingdom1 site, 1 recruiting
- Not yet recruiting
Great Ormond Street Hospital for Children
London, WC1N 3JH
James Davison, 0207 405 9200 ext. 0074, james.davison@gosh.nhs.uk
About this study
Official title: 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)
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.
- Conditions
- Mucopolysaccharidosis IIIB
- Being tested
- JR-446
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
JR-446Drug
IV infusion
| Study group | Role | What they receive |
|---|---|---|
| JR-446 | Experimental | Arm: 1 Receives: Drug: JR-446 |
What is being measured
The primary outcome is the main question the study is designed to answer.
To establish the safety and tolerability of JR-446 in MPS IIIB patients following repeated dose administration
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.
Measured: Up to 1 year (multiple visits)
Secondary outcomes (12)
Change From Baseline in Cerebrospinal Fluid Heparan Sulfate Concentration
Measured: Through Week 53 (up to 1 year; multiple visits)
Absolute Change From Baseline in Serum Heparan Sulfate Concentration
Measured: Through Week 53 (up to 1 year; multiple visits)
Percent Change From Baseline in Serum Heparan Sulfate Concentration
Measured: Through Week 53 (up to 1 year; multiple visits)
Absolute Change From Baseline in Urine Heparan Sulfate Concentration
Measured: Through Week 53 (up to 1 year; multiple visits)
Percent Change From Baseline in Urine Heparan Sulfate Concentration
Measured: Through Week 53 (up to 1 year; multiple visits)
Absolute Change From Baseline in Serum Neurofilament Light Chain Concentration
Measured: Through Week 53 (up to 1 year; multiple visits)
Percent Change From Baseline in Serum Neurofilament Light Chain Concentration
Measured: Through Week 53 (up to 1 year; multiple visits)
Change in Cognitive Function Assessments From Baseline
Measured: Through Week 53 (up to 1 year)
Change in Brain MRIs From Baseline
Measured: Through Week 53 (up to 1 year)
Change in Height Standard Deviation Score (SDS) From Baseline (using WHO child growth standards)
Measured: Through Week 53 (up to 1 year)
Change in Weight SDS From Baseline (using WHO child growth standards)
Measured: Through Week 53 (up to 1 year)
Change in Body Mass Index (BMI) SDS From Baseline (using WHO child growth standards)
Measured: Through Week 53 (up to 1 year)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Jun 2026
- Study start9 Sep 2026
- Primary completion30 Jun 2028 (estimated)
- Study completion30 Sep 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Mucopolysaccharidosis IIIBStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1/2
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 12 participants (estimated)
Sponsor and investigators
- Lead sponsor
- JCR Pharmaceuticals Co., Ltd.
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- MEDIPAL HOLDINGS CORPORATION
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07640984
- Sponsor's protocol ID
- JR-446-201
- Status last verified
- Jul 2026
- First submitted
- 14 May 2026
- Last updated
- 21 Sep 2026
- Results posted
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 21 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- 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)
- ClinicalTrials.gov ID
- NCT07640984
- Acronym / sponsor ID
- JR-446-201
- Conditions
- Mucopolysaccharidosis IIIB
- Phase
- Phase 1/2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 12 participants (estimated)
- Lead sponsor
- JCR Pharmaceuticals Co., Ltd.Industry (pharma, biotech, devices)
- Collaborators
- MEDIPAL HOLDINGS CORPORATION
- Study start
- 9 Sep 2026 (actual)
- Primary completion
- 30 Jun 2028 (estimated)
- Study completion
- 30 Sep 2028 (estimated)
- First posted
- 11 Jun 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| JR-446 | Experimental | Drug: JR-446Arm: 1 |
Who may qualify
- Ages
- Up to 5 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child
Key inclusion criteria (3 listed)
- Patients with confirmed MPS IIIB with a phenotype of MPS IIIB that is not classified as slowly progressive (i.e., not attenuated).
- A chronological age <6 years.
- 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.
Key exclusion criteria (11 listed)
- Contraindication for lumbar puncture or MRI.
- 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.
- 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.
- A participant who has received gene therapy treatment or hematopoietic stem cell transplantation (HSCT) with successful engraftment.
- Serious drug allergy or hypersensitivity to any components of JR-446 or medications likely prescribed during the trial.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| JR-446IV infusion | Drug | JR-446 |
Primary outcome
To establish the safety and tolerability of JR-446 in MPS IIIB patients following repeated dose administration
Time frame: Up 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.
12 secondary outcomes
Change From Baseline in Cerebrospinal Fluid Heparan Sulfate Concentration
Time frame: Through Week 53 (up to 1 year; multiple visits)
Absolute Change From Baseline in Serum Heparan Sulfate Concentration
Time frame: Through Week 53 (up to 1 year; multiple visits)
Percent Change From Baseline in Serum Heparan Sulfate Concentration
Time frame: Through Week 53 (up to 1 year; multiple visits)
Absolute Change From Baseline in Urine Heparan Sulfate Concentration
Time frame: Through Week 53 (up to 1 year; multiple visits)
Percent Change From Baseline in Urine Heparan Sulfate Concentration
Time frame: Through Week 53 (up to 1 year; multiple visits)
Absolute Change From Baseline in Serum Neurofilament Light Chain Concentration
Time frame: Through Week 53 (up to 1 year; multiple visits)
Percent Change From Baseline in Serum Neurofilament Light Chain Concentration
Time frame: Through Week 53 (up to 1 year; multiple visits)
Change in Cognitive Function Assessments From Baseline
Time frame: Through Week 53 (up to 1 year)
Change in Brain MRIs From Baseline
Time frame: Through Week 53 (up to 1 year)
Change in Height Standard Deviation Score (SDS) From Baseline (using WHO child growth standards)
Time frame: Through Week 53 (up to 1 year)
Change in Weight SDS From Baseline (using WHO child growth standards)
Time frame: Through Week 53 (up to 1 year)
Change in Body Mass Index (BMI) SDS From Baseline (using WHO child growth standards)
Time frame: Through Week 53 (up to 1 year)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 21 Sep 2026.
- Individual participant dataSharing planned: No
Related trials for Mucopolysaccharidosis IIIB
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Intracerebroventricular Tralesinidase Alfa in Participants With MPS IIIB (Sanfilippo Syndrome Type B)
MPS IIIB
Not yet recruitingPhase 1/2
Single Injection of rAAV9-CMV-hNAGLUop Gene for Patients With Mucopolysaccharidosis (MPS) IIIB
Sanfilippo Syndrome (MPS III)
Enrolling by invitationPhase 4
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
5 sites in 3 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1/2 study testing JR-446 in people with Mucopolysaccharidosis IIIB, run by JCR Pharmaceuticals Co., Ltd. at 5 sites in 3 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 21 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 5 sites in United States, Germany, United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this combined phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact JCR Pharmaceuticals Co., Ltd. (+81-797-32-8582, clinical_development@jp.jcrpharm.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
To establish the safety and tolerability of JR-446 in MPS IIIB patients following repeated dose administration (time frame: Up to 1 year (multiple visits)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 21 Sep 2026.