Mucopolysaccharidosis IIPhase 2NCT03708965
An Extension Study of JR-141-BR21 in Patients With Mucopolysaccharidosis II
A Phase 2 study testing JR-141 in people with Mucopolysaccharidosis II, run by JCR Pharmaceuticals Co., Ltd. at 2 sites in Brazil.
Trial summary
A Phase II open-label, parallel group, 2 sites (Brazil), designed to evaluate the long term safety and efficacy of study drug for the treatment of the MPS II. Read more about this study
- Who is it for?
- Ages 0 years and older, men only
- Conditions the study is for
- Mucopolysaccharidosis II
- What is being tested?
- JR-141
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 19 participants
- Where
- 2 sitesBrazil
- Study dates
- 1 Jan 2019to 31 Dec 2027
- Phase
- Phase 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 0 years and older
- Men only
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- Patients who will have completed clinical trial JR-141-BR21.
- Capable of providing written consent by himself, unless the patient is under the age of 18 years at the time of informed consent process, or it is not possible to obtain consent from the patient himself due to his intellectual disabilities associated with MPS II.
- In the case of a patient who is under the age of 18 years or from whom it is not possible to obtain consent due to his intellectual disabilities associated with MSP II, he may be included if written consent can be provided by legal representative; however written consent should be obtained from the patient himself too, wherever possible.
Who cannot join
- Refusal to sign the informed consent form.
- Unable to perform the study procedures, except for neurocognitive testing.
- Previous engrafted BMT/HSCT.
- Judged by the investigator or subinvestigator as being unable to undergo lumbar puncture, including those who have difficulties in taking a position for lumber puncture due to joint contracture or those who are likely to experience difficulty breathing during the lumbar puncture process.
- Judged by the investigator or subinvestigator to be ineligible to participate in the study due to a history of a serious drug allergy or sensitivity.
- Otherwise judged by the investigator or subinvestigator to be ineligible to participate in the study out of consideration for the subject safety.
Trial locations and contacts
2 sites in 1 country.
Brazil2 sites
Grupo de Pesquisa Clínica em Genética Médica - HCPA
Porto Alegre
Igeim - Unifesp
São Paulo
About this study
A Phase II open-label, parallel group, 2 sites (Brazil), designed to evaluate the long term safety and efficacy of study drug for the treatment of the MPS II.
- Conditions
- Mucopolysaccharidosis II
- Being tested
- JR-141
- Medical subject headings
- Mucopolysaccharidosis II
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
JR-141Drug
IV infusion (lyophilized powder)
| Study group | Role | What they receive |
|---|---|---|
| JR-141 | Experimental | Subjects will be assigned to 1.0, 2.0 or 4.0 mg of JR-141 per kg of body weight once every week (the same dose taken during the previous study) in the beginning of the study.
During the study, the dose of all subjects will be switched to the selected one*.
* The dose was determined to be 2.0 mg/kg/week based on the safety and efficacy data of JR-141-BR21 study. Receives: Drug: JR-141 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of participants with Adverse Events
Measured: From screening up to the end of study, up to approximately 5 years
Secondary outcomes (6)
Urinary heparan sulfate concentrations
Measured: through study completion, an average of 52 weeks, up to approximately 5 years
Urinary dermatan sulfate concentrations
Measured: through study completion, an average of 52 weeks, up to approximately 5 years
Serum heparan sulfate concentrations
Measured: through study completion, an average of 52 weeks, up to approximately 5 years
Serum dermatan sulfate concentrations
Measured: through study completion, an average of 52 weeks, up to approximately 5 years
Liver and spleen volumes (MRI)
Measured: through study completion, an average of 52 weeks, up to approximately 5 years
Echocardiography
Measured: through study completion, an average of 52 weeks, up to approximately 5 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Oct 2018
- Study start1 Jan 2019
- Primary completion31 Dec 2026 (estimated)
- Study completion31 Dec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Mucopolysaccharidosis IIStudies 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 2
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 19 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
- NCT03708965
- Sponsor's protocol ID
- JR-141-BR22
- Status last verified
- Aug 2026
- First submitted
- 27 Sep 2018
- Last updated
- 8 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 8 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Extension Study of JR-141-BR21 in Patients With Mucopolysaccharidosis II
- ClinicalTrials.gov ID
- NCT03708965
- Acronym / sponsor ID
- JR-141-BR22
- Conditions
- Mucopolysaccharidosis II
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 19 participants (actual)
- Lead sponsor
- JCR Pharmaceuticals Co., Ltd.Industry (pharma, biotech, devices)
- Study start
- 1 Jan 2019 (actual)
- Primary completion
- 31 Dec 2026 (estimated)
- Study completion
- 31 Dec 2027 (estimated)
- First posted
- 17 Oct 2018 (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 II open-label, parallel group, 2 sites (Brazil), designed to evaluate the long term safety and efficacy of study drug for the treatment of the MPS II.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| JR-141 | Experimental | Drug: JR-141Subjects will be assigned to 1.0, 2.0 or 4.0 mg of JR-141 per kg of body weight once every week (the same dose taken during the previous study) in the beginning of the study. During the study, the dose of all subjects will be switched to the selected one*. * The dose was determined to be 2.0 mg/kg/week based on the safety and efficacy data of JR-141-BR21 study. |
Who may qualify
- Ages
- 0 years and older
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (3 listed)
- Patients who will have completed clinical trial JR-141-BR21.
- Capable of providing written consent by himself, unless the patient is under the age of 18 years at the time of informed consent process, or it is not possible to obtain consent from the patient himself due to his intellectual disabilities associated with MPS II.
- In the case of a patient who is under the age of 18 years or from whom it is not possible to obtain consent due to his intellectual disabilities associated with MSP II, he may be included if written consent can be provided by legal representative; however written consent should be obtained from the patient himself too, wherever possible.
Key exclusion criteria (6 listed)
- Refusal to sign the informed consent form.
- Unable to perform the study procedures, except for neurocognitive testing.
- Previous engrafted BMT/HSCT.
- Judged by the investigator or subinvestigator as being unable to undergo lumbar puncture, including those who have difficulties in taking a position for lumber puncture due to joint contracture or those who are likely to experience difficulty breathing during the lumbar puncture process.
- Judged by the investigator or subinvestigator to be ineligible to participate in the study due to a history of a serious drug allergy or sensitivity.
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-141IV infusion (lyophilized powder) | Drug | JR-141 |
Primary outcome
Number of participants with Adverse Events
Time frame: From screening up to the end of study, up to approximately 5 years
6 secondary outcomes
Urinary heparan sulfate concentrations
Time frame: through study completion, an average of 52 weeks, up to approximately 5 years
Urinary dermatan sulfate concentrations
Time frame: through study completion, an average of 52 weeks, up to approximately 5 years
Serum heparan sulfate concentrations
Time frame: through study completion, an average of 52 weeks, up to approximately 5 years
Serum dermatan sulfate concentrations
Time frame: through study completion, an average of 52 weeks, up to approximately 5 years
Liver and spleen volumes (MRI)
Time frame: through study completion, an average of 52 weeks, up to approximately 5 years
Echocardiography
Time frame: through study completion, an average of 52 weeks, up to approximately 5 years
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 8 Sep 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.
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing JR-141 in people with Mucopolysaccharidosis II, run by JCR Pharmaceuticals Co., Ltd. at 2 sites in Brazil.
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 6 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 8 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 2 sites in Brazil. 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 phase mean?
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?
Number of participants with Adverse Events (time frame: From screening up to the end of study, up to approximately 5 years). 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 8 Sep 2026.