Not yet recruitingPHASE1, PHASE2INTERVENTIONAL

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

This study is investigating a new medicine, JR-446, for children under 6 who have a rare genetic condition called Mucopolysaccharidosis Type IIIB (MPS IIIB). This condition affects how the body breaks down certain sugars, which can lead to various health problems. We want to find out if JR-446 is safe for children and how well their bodies react to it. We also hope to see if it can help improve some of the symptoms of MPS IIIB. This is an early-stage study, meaning it’s one of the first times this medicine is being tested in children with the condition, and all participants will receive the medicine.

At a glance

Status

Not yet recruiting

Phase

PHASE1, PHASE2

Sponsor

JCR Pharmaceuticals Co., Ltd.

Enrolment target

Start

18 Jun 2026

Estimated completion

30 Sep 2028

Mucopolysaccharidosis IIIB

What is this study about?

This study is focusing on a rare genetic condition called Mucopolysaccharidosis Type IIIB, often shortened to MPS IIIB. It's a condition that children are born with and it affects how their bodies process certain complex sugars. Because of this, these sugars can build up in different parts of the body, including the brain, which can cause various health challenges over time. Currently, there aren't many specific treatments for MPS IIIB, so finding new ways to help children with this condition is very important.

The main goal of this study is to look at a new medicine called JR-446. We want to find out how safe it is for children with MPS IIIB and how well their bodies cope with it. We also want to understand if the medicine has any positive effects on the condition itself. This type of study is called a 'Phase I/II trial', which means it's an early step in testing a new medicine, focusing on safety first, and then looking for early signs that it might be helpful.

By taking part, children will receive the study medicine, JR-446. The information we gather will be crucial in understanding whether this medicine could eventually become a treatment option for children with MPS IIIB in the future. We hope this research will bring us closer to improving the lives of those affected by this condition.

Key takeaways

This study is for children under 6 with MPS IIIB.
It's testing a new medicine called JR-446.
The main goals are to check safety and see if the medicine helps.
All children in the study will receive the medicine.
Close medical monitoring will be provided throughout the study.

Who may be eligible?

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.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

Is your child under 6 years old?
Does your child have a definite diagnosis of MPS IIIB (not a very slow-progressing type)?
Can your child do age-appropriate developmental tests?
Has your child NOT had other new experimental drugs in the last 4 months?
Does your child NOT have serious allergies to common medicines or the study drug?
Does your child NOT have uncontrolled seizures or serious bleeding problems?

Answer every question to see your result.

What does participation involve?

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.

Potential risks and benefits

Taking part in any medical study has both potential benefits and risks. While JR-446 is a new medicine and we don't yet know if it will definitely help, there's a chance it could have a positive effect on your child's MPS IIIB. Your child will also receive very close medical attention and monitoring from a team of specialists. However, like all medicines, JR-446 might have side effects, and some of the tests and procedures in the study, like blood tests or MRI scans, carry their own small risks. The study team will explain all potential risks in detail, and it's important to remember that you are free to withdraw your child from the study at any time, for any reason, without it affecting their future medical care.

Locations (5)

Children's Hospital Oakland Research Institution, Attn: 2900 Wing
Verified postcode
Oakland, United States
UPMC Children's Hospital of Pittsburgh
Verified postcode
Pittsburgh, United States
Lysosomal and Rare Disorders Research and Treatment Center (LDRTC)
Verified postcode
Fairfax, United States
University Medical Center Hamburg-Eppendorf
Verified postcode
Hamburg, Germany
Great Ormond Street Hospital for Children
Verified postcode
London, United Kingdom

Common questions

What is MPS IIIB?

MPS IIIB is a rare condition where the body can't properly break down certain sugars, leading to their build-up in the body, which can cause health issues.

Is this medicine a cure?

This is an early study to see if the medicine is safe and might help. We don't know if it's a cure, but we hope to learn if it can make a difference.

What is a 'Phase I/II' study?

It means this is one of the first times the medicine is being tested in children with the condition, mainly to check safety and look for early signs of it working.

Will my child definitely get the new medicine?

Yes, in this particular study, all children who take part will receive the study medicine, JR-446.

What if we change our mind about participating?

You are free to decide to leave the study at any time, for any reason, and this won't affect your child's usual medical care.

How to find out more

JCR Pharmaceuticals Co., Ltd.

clinical_development@jp.jcrpharm.com +81-797-32-8582 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.