Mucopolysaccharidosis III-BPhase 1/2NCT06488924
An Open-label Phase I/II Study of JR-446 in Mucopolysaccharidosis Type IIIB
A Phase 1/2 study testing JR-446 in people with Mucopolysaccharidosis III-B, run by JCR Pharmaceuticals Co., Ltd. at 4 sites in Japan.
Trial summary
A Phase I/ II, open-label study, designed to evaluate the safety and explore efficacy of the study drug in development for the treatment of MPS IIIB patients. Read more about this study
- Who is it for?
- Ages Up to 17 years
- Conditions the study is for
- Mucopolysaccharidosis III-B
- 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
- 10 participants
- Where
- 4 sitesJapan
- Study dates
- 5 Nov 2024to 30 Apr 2030
- 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 17 years
- All sexes
- No healthy volunteers
- Child
Who may be able to join
- Chronological age of <18 years
- Confirmed diagnosis of MPS IIIB
Who cannot join
- Prior experience to gene therapy or HSCT with successful engraftment
- Past use of another investigational drug or product in last 4 months or 5 half-lives (whichever is longer) before signing ICF
- Current participation in a clinical trial or past participation (within 30 days of enrolment into this study) in a study involving invasive procedures
- Past use of Genistein or Kineret (anakinra) within 4 months before signing ICF
- Serious drug allergy or hypersensitivity
- Contraindication for lumbar puncture or MRI
- 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
- 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
4 sites in 1 country.
Japan4 sites
Hiroshima University Hospital
Hiroshima
University of the Ryukyus Hospital
Okinawa
National Center for Child Health and Development
Tokyo
Mie University Hospital
Tsu
About this study
A Phase I/ II, open-label study, designed to evaluate the safety and explore efficacy of the study drug in development for the treatment of MPS IIIB patients.
- Conditions
- Mucopolysaccharidosis III-B
- Being tested
- JR-446
- Medical subject headings
- Mucopolysaccharidosis III
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 | Not described 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 MPSIIIB patients
Measured: up to 4 years (multiple visits)
To determine the pharmacodynamic effects of JR-446 in MPSIIIB patients
Measured: up to 4 years (multiple visits)
Secondary outcomes (2)
To assess PK profile of JR-446 in MPSIIIB patients
Measured: up to 4 years (multiple visits)
To explore the potential efficacy of JR-446 in the treatment of patients with MPS IIIB
Measured: up to 4 years (multiple visits)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Jul 2024
- Study start5 Nov 2024
- Primary completion30 Apr 2030 (estimated)
- Study completion30 Apr 2030 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Mucopolysaccharidosis III-BStudies 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
- 10 participants (estimated)
Sponsor and investigators
- Lead sponsor
- JCR Pharmaceuticals Co., Ltd.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06488924
- Sponsor's protocol ID
- JR-446-101
- Status last verified
- Sep 2026
- First submitted
- 28 Jun 2024
- Last updated
- 1 Oct 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 1 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Open-label Phase I/II Study of JR-446 in Mucopolysaccharidosis Type IIIB
- ClinicalTrials.gov ID
- NCT06488924
- Acronym / sponsor ID
- JR-446-101
- Conditions
- Mucopolysaccharidosis III-B
- Phase
- Phase 1/2
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 10 participants (estimated)
- Lead sponsor
- JCR Pharmaceuticals Co., Ltd.Industry (pharma, biotech, devices)
- Study start
- 5 Nov 2024 (actual)
- Primary completion
- 30 Apr 2030 (estimated)
- Study completion
- 30 Apr 2030 (estimated)
- First posted
- 5 Jul 2024 (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.
A Phase I/ II, open-label study, designed to evaluate the safety and explore efficacy of the study drug in development for the treatment of MPS IIIB patients.
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-446 |
Who may qualify
- Ages
- Up to 17 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child
Key inclusion criteria (2 listed)
- Chronological age of <18 years
- Confirmed diagnosis of MPS IIIB
Key exclusion criteria (8 listed)
- Prior experience to gene therapy or HSCT with successful engraftment
- Past use of another investigational drug or product in last 4 months or 5 half-lives (whichever is longer) before signing ICF
- Current participation in a clinical trial or past participation (within 30 days of enrolment into this study) in a study involving invasive procedures
- Past use of Genistein or Kineret (anakinra) within 4 months before signing ICF
- Serious drug allergy or hypersensitivity
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 MPSIIIB patients
Time frame: up to 4 years (multiple visits)
To determine the pharmacodynamic effects of JR-446 in MPSIIIB patients
Time frame: up to 4 years (multiple visits)
2 secondary outcomes
To assess PK profile of JR-446 in MPSIIIB patients
Time frame: up to 4 years (multiple visits)
To explore the potential efficacy of JR-446 in the treatment of patients with MPS IIIB
Time frame: up to 4 years (multiple visits)
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 1 Oct 2026.
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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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
4 sites in 1 country: 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 III-B, run by JCR Pharmaceuticals Co., Ltd. at 4 sites in Japan.
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 2 inclusion and 8 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: under way, not looking for participants, as of the sponsor's last update on 1 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 4 sites in Japan. 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?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
To establish the safety and tolerability of JR-446 in MPSIIIB patients (time frame: up to 4 years (multiple visits)). The study lists 2 primary outcomes in all. 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 1 Oct 2026.