A Phase I/II Trial of JR-446 in Mucopolysaccharidosis Type IIIB (MPS IIIB)

This study is looking for children under 6 years old who have been diagnosed with Mucopolysaccharidosis Type IIIB (MPS IIIB). It’s important that their specific type of MPS IIIB isn't a very slow-progressing form. We also need to check that children can do certain developmental tests that show how they are learning and thinking, and get a score that is not too low.

There are also some reasons why a child might not be able to join the study. For example, if they have certain medical conditions that might make a lumbar puncture (a procedure where a small amount of fluid is taken from the spine) or an MRI scan unsafe. Children can't have been in another medical study using a new drug within the last four months, or had gene therapy or a stem cell transplant. Also, severe allergies to the study medicine or other trial medications would prevent participation.

Other things that might mean a child can't join include uncontrolled seizures, a history of bleeding problems, certain infections like HIV or active hepatitis, or any other serious medical issue that the study doctor thinks would make it unsafe or difficult for them to take part.

If your child takes part in this study, they will receive the new medicine called JR-446. The study will involve regular visits to the hospital or clinic so the doctors can carefully monitor your child's health and how they are responding to the medicine. These visits will likely include various check-ups, blood tests, and possibly some scans like an MRI. Your child may also have procedures like a lumbar puncture, where a tiny amount of fluid is gently taken from around the spine, to see how the medicine is working. The study is designed to assess the safety and effects of the medicine, so there will be ongoing assessments of your child's development and well-being. The total length of your child's participation will be explained by the study team, and you will be kept informed every step of the way.