In short
Clinical trials of Idursulfase are studying long-term safety and treatment effects in people with Hunter syndrome, also called mucopolysaccharidosis type II (MPS II). These studies include patients with cognitive impairment, as well as pediatric and young adult participants. The trials look at safety, brain and body outcomes, and other measures of disease control.
Key points
- Clinical trials of Idursulfase are being done in people with Hunter syndrome, also called mucopolysaccharidosis type II (MPS II). The studies include participants with cognitive impairment, and some include pediatric and young adult patients. One Phase 3 extension study is focused on long-term safety of intrathecal Idursulfase-IT, while other Phase 3 and Phase 4 studies compare treatment effects and measure brain-related and daily-life outcomes. The main endpoints include safety, cognitive scores, cerebrospinal fluid heparan sulfate, and adaptive behavior. All listed studies are authorised and use interventional designs.
Trial overview
The trial set includes three interventional studies of Idursulfase in people with Hunter syndrome, also called mucopolysaccharidosis type II (MPS II).
All three studies are listed as Authorised, and they range from Phase 3 to Phase 4.
Who can participate
One study enrolls subjects with Hunter syndrome and cognitive impairment, which means the condition affects thinking or learning.
Another study includes MPS II patients and is designed for pediatric and young adult participants.
The open-label extension study has a very small planned group, with 8 participants, while the other two studies plan to enroll 80 and 64 participants.
What the trials measure
The main safety endpoint in the extension study is the safety of intrathecal Idursulfase-IT, which is checked by tracking adverse events and whether they are linked to the treatment, the device used, the surgical procedure, or the IV Elaprase infusion.
In one Phase 3 study, the main outcomes include change in BSID-III cognitive domain scores and change in CSF HS levels. BSID-III is a developmental test, and CSF HS means heparan sulfate measured in cerebrospinal fluid.
In the Phase 4 study, the main outcomes are the ratio to baseline in CSF HS concentration and change from baseline in Vineland-3. Vineland-3 is a measure of adaptive behavior, such as daily living and communication skills.
Trial designs and phases
The extension study is a Phase 3 open-label extension, which means everyone in the study knows which treatment is being given, and the study continues earlier research to collect long-term safety data.
The JR-141 study is a Phase 3 interventional trial that aims to show efficacy, safety, and pharmacokinetics. Pharmacokinetics means how the body handles the study drug over time.
The DNL310 study is a Phase 4 interventional trial comparing tividenofusp alfa (DNL310) with Idursulfase in pediatric and young adult participants with MPS II.
Key trials in this set
2023-504127-90-00 is an open-label extension study for people already in studies HGT-HIT-046 and SHP609-302. It looks at long-term safety of intrathecal Idursulfase-IT given together with intravenous Elaprase in subjects with Hunter syndrome and cognitive impairment.
NCT04573023 studies JR-141 in people with MPS II / Hunter syndrome. Its goals are to test whether the treatment helps central nervous system symptoms and body symptoms, and to assess safety and pharmacokinetics.
NCT05371613 compares tividenofusp alfa (DNL310) with Idursulfase in pediatric and young adult participants with neuronopathic or non-neuronopathic MPS II. The study focuses on brain-related activity and adaptive behavior, using CSF HS and Vineland-3 as key measures.
What these studies may mean for patients
These trials show that researchers are studying Idursulfase in different ways, including long-term follow-up and comparison with other treatments.
Some studies focus on the central nervous system, which is the brain and spinal cord, because MPS II can affect thinking and daily function.
Overall, the trial data suggest a research focus on both safety and treatment effect in people living with Hunter syndrome across different age groups.