Mucopolysaccharidosis III-APhase 1/2NCT06095388
Phase I/II Study of JR-441 in Patients With Mucopolysaccharidosis Type IIIA
A Phase 1/2 study testing JR-441 in people with Mucopolysaccharidosis III-A, run by JCR Pharmaceuticals Co., Ltd. at 1 site in Germany.
Trial summary
A Phase I/ II, open-label, randomized, 2-arm study, designed to evaluate the safety and explore efficacy of the study drug in development for the treatment of MPS IIIA patients. Read more about this study
- Who is it for?
- Ages 1 year to 18 years
- Conditions the study is for
- Mucopolysaccharidosis III-A
- What is being tested?
- JR-441
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 15 participants
- Where
- 1 siteGermany
- Study dates
- 4 Oct 2023to 31 Oct 2029
- 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 1 year to 18 years
- All sexes
- No healthy volunteers
- Child, Adult
Who may be able to join
- Chronological age of ≥1 year and ≤18 years.
- Confirmed diagnosis of MPS IIIA.
- Body weight ≥ 10 kg.
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
1 site in 1 country.
About this study
Official title: Phase I/II Study of Weekly Infusions of JR-441 in Patients With Mucopolysaccharidosis Type IIIA
A Phase I/ II, open-label, randomized, 2-arm study, designed to evaluate the safety and explore efficacy of the study drug in development for the treatment of MPS IIIA patients.
- Conditions
- Mucopolysaccharidosis III-A
- Being tested
- JR-441
- 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-441Drug
Also called posnafusp alfa
IV infusion
JR-441Drug
Also called posnafusp alfa
IV infusion
JR-441Drug
Also called posnafusp alfa
IV infusion
| Study group | Role | What they receive |
|---|---|---|
| JR-441 low dose | Experimental | Not described Receives: Drug: JR-441 |
| JR-441 medium dose | Experimental | Not described Receives: Drug: JR-441 |
| JR-441 high dose | Experimental | Not described Receives: Drug: JR-441 |
What is being measured
The primary outcome is the main question the study is designed to answer.
To evaluate the tolerability of JR-441 in MPSIIIA patients
Adverse events will be reported and graded, laboratory tests will be conducted and vital signs will be monitored
Measured: up to 5 years (multiple visits)
To assess the safety of JR-441 in MPSIII-A patients
Number and severity of infusion-associated reactions, including anaphylaxis
Measured: up to 5 years (multiple visits)
Secondary outcomes (4)
Plasma drug concentration
Measured: up to 5 years (multiple visits)
Plasma PK parameters
Measured: up to 5 years (multiple visits)
Change from baseline in heparan sulfate levels in cerebrospinal fluid (CSF), serum and urine
Measured: up to 5 years (multiple visits)
Change from baseline in cognitive function
Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III) and/or Kaufman Assessment Battery for Children, Second Edition (KABC-II)
Measured: up to 5 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 posted23 Oct 2023
- Study start4 Oct 2023
- Primary completion31 Oct 2029 (estimated)
- Study completion31 Oct 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Mucopolysaccharidosis III-AStudies 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
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 15 participants (actual)
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
- NCT06095388
- Sponsor's protocol ID
- JR-441-101
- Status last verified
- Sep 2026
- First submitted
- 13 Sep 2023
- Last updated
- 4 Sep 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 4 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Phase I/II Study of Weekly Infusions of JR-441 in Patients With Mucopolysaccharidosis Type IIIA
- ClinicalTrials.gov ID
- NCT06095388
- Acronym / sponsor ID
- JR-441-101
- Conditions
- Mucopolysaccharidosis III-A
- Phase
- Phase 1/2
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 15 participants (actual)
- Lead sponsor
- JCR Pharmaceuticals Co., Ltd.Industry (pharma, biotech, devices)
- Study start
- 4 Oct 2023 (actual)
- Primary completion
- 31 Oct 2029 (estimated)
- Study completion
- 31 Oct 2029 (estimated)
- First posted
- 23 Oct 2023 (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, randomized, 2-arm study, designed to evaluate the safety and explore efficacy of the study drug in development for the treatment of MPS IIIA patients.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| JR-441 low dose | Experimental | Drug: JR-441 |
| JR-441 medium dose | Experimental | Drug: JR-441 |
| JR-441 high dose | Experimental | Drug: JR-441 |
Who may qualify
- Ages
- 1 year to 18 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (3 listed)
- Chronological age of ≥1 year and ≤18 years.
- Confirmed diagnosis of MPS IIIA.
- Body weight ≥ 10 kg.
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-441Also: posnafusp alfaIV infusion | Drug | JR-441 low dose |
| JR-441Also: posnafusp alfaIV infusion | Drug | JR-441 medium dose |
| JR-441Also: posnafusp alfaIV infusion | Drug | JR-441 high dose |
Primary outcome
To evaluate the tolerability of JR-441 in MPSIIIA patients
Time frame: up to 5 years (multiple visits)
Adverse events will be reported and graded, laboratory tests will be conducted and vital signs will be monitored
To assess the safety of JR-441 in MPSIII-A patients
Time frame: up to 5 years (multiple visits)
Number and severity of infusion-associated reactions, including anaphylaxis
4 secondary outcomes
Plasma drug concentration
Time frame: up to 5 years (multiple visits)
Plasma PK parameters
Time frame: up to 5 years (multiple visits)
Change from baseline in heparan sulfate levels in cerebrospinal fluid (CSF), serum and urine
Time frame: up to 5 years (multiple visits)
Change from baseline in cognitive function
Time frame: up to 5 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 4 Sep 2026.
Related trials for Mucopolysaccharidosis III-A
RecruitingPhase 1/2
Study of DNL126 in Pediatric Participants With Mucopolysaccharidosis Type IIIA (Sanfilippo Syndrome Type A)
Mucopolysaccharidosis Type IIIA
Not yet recruitingObservational study
MPS IIIA Disease Monitoring Program
MPS IIIA, Sanfilippo Syndrome
Active, not recruitingPhase 3
A Phase III Study of JR-141 in Patients With Mucopolysaccharidosis II (STARLIGHT)
Mucopolysaccharidosis II
RecruitingPhase 2/3
Phase I/II/III Gene Transfer Clinical Trial of scAAV9.U1a.hSGSH
MPS IIIA, Sanfilippo Syndrome
Not yet recruitingPhase 3
Intracerebroventricular Tralesinidase Alfa in Participants With MPS IIIB (Sanfilippo Syndrome Type B)
MPS IIIB
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.
1 site 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-441 in people with Mucopolysaccharidosis III-A, run by JCR Pharmaceuticals Co., Ltd. at 1 site in Germany.
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 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 4 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 1 site in Germany. 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 evaluate the tolerability of JR-441 in MPSIIIA patients (time frame: up to 5 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 4 Sep 2026.