A Phase 2 interventional study of JR-141 in Mucopolysaccharidosis II, sponsored by JCR Pharmaceuticals Co., Ltd.. Active, not recruiting at 2 sites in Brazil. Open to male participants aged 0 Years and older. Per ClinicalTrials.gov, last updated 2026-09-08.
Sponsored by JCR Pharmaceuticals Co., Ltd. · Phase 2, Interventional, and Treatment
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.
71 studies on the registry are indexed under Mucopolysaccharidosis II; 8 are open to participants now.
This study's enrollment of 19 is close to the median of 20 across 43 interventional studies indexed under Mucopolysaccharidosis II.
Browse Mucopolysaccharidosis II studies →JCR Pharmaceuticals Co., Ltd. is the lead sponsor of 13 studies on the registry; 3 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
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.
Drug: JR-141
IV infusion (lyophilized powder)
Number of participants with Adverse Events
Time frame: From screening up to the end of study, up to approximately 5 years
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
This study is active, not recruiting, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.
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JCR Pharmaceuticals Co., Ltd.