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Study of Weekly Infusions of JR-441 for Patients with Mucopolysaccharidosis Type IIIA

Verified siteInvestigationalNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying a rare genetic disorder called Mucopolysaccharidosis type IIIA (MPS IIIA). MPS IIIA is a condition that affects the body's ability to break down certain sugar molecules, leading to various health issues. The treatment being tested in this study is called JR-441, which is a special type of medication designed to help manage the symptoms of MPS IIIA. JR-441 is a lyophilized powder, which means it is a freeze-dried substance that is prepared for injection. It works by using a protein that targets specific receptors in the body to help improve the condition.

The purpose of this study is to evaluate the safety and explore the effectiveness of JR-441 in patients with MPS IIIA. Participants in the study will receive weekly infusions of JR-441. The study will monitor the occurrence of any side effects and changes in health indicators such as blood tests, vital signs, and heart function. The study will also look at how the drug is processed in the body and its impact on cognitive function and behavior.

This trial is expected to run until 2030, with the aim of gathering comprehensive data on the safety and potential benefits of JR-441 for individuals with MPS IIIA. Participants will be closely monitored throughout the study to ensure their well-being and to collect valuable information that could lead to improved treatments for this challenging condition.

The research process

The trial runs in 4 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Joining the study

    Upon joining the study, the patient will receive an initial assessment to confirm eligibility. This includes verifying the diagnosis of Mucopolysaccharidosis type IIIA (MPS IIIA) and ensuring the patient meets the age and weight criteria.

    The patient or their legal representative must provide informed consent to participate in the study.

  2. Step 2

    Treatment initiation

    The patient will begin receiving the study medication, JR-441, which is a lyophilized powder prepared for injection.

    The medication is administered through an intravenous infusion once a week.

  3. Step 3

    Monitoring and assessments

    Throughout the study, the patient will undergo regular monitoring to evaluate safety and effectiveness. This includes checking for any adverse events, changes in laboratory tests, and vital signs.

    The patient will also have periodic assessments of cognitive function and adaptive behavior.

  4. Step 4

    Completion of treatment

    The study is expected to continue until January 11, 2030. The patient will receive weekly infusions of JR-441 until the end of the study or until they choose to withdraw.

    After the final administration of the study drug, follow-up assessments will be conducted to ensure the patient's well-being.

Who can join the trial?

9 criteria

  • The patient must be between **1 year** and **18 years** old at the time of signing the consent form.
  • The patient or their legal representative, like parents or guardians, must sign a written consent form approved by an ethics committee. If possible, the patient should also give their agreement to participate.
  • The patient must have a confirmed diagnosis of **Mucopolysaccharidosis type IIIA (MPS IIIA)**. This includes:
    • Low activity of a specific enzyme called **N-sulphoglucosamine sulphohydrolase (SGSH)** in certain cells.
    • Normal activity of at least one other enzyme to rule out other conditions.
    • Presence of specific genetic changes in the **SGSH gene**.
    • The patient must weigh at least **10 kg**.
    • If the patient is a female who can have children, or if the patient has a female partner who can have children, they must agree to use a reliable method of birth control during the study and for a certain period after the study ends.
    • If the patient has hearing problems and needs hearing aids, they should use them as much as possible, especially during tests that check development and learning.
    • The patient must be in stable health and able to follow the study requirements, including travel, without causing too much difficulty for themselves or their family.
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Investigated drugs

JR-441 is an investigational medication being studied for its potential to treat patients with mucopolysaccharidosis type IIIA (MPS IIIA). This medication is administered through weekly infusions. The main goal of the trial is to assess the safety of JR-441 and to explore its effectiveness in managing the symptoms of MPS IIIA, a rare genetic disorder that affects the body's ability to break down certain sugars.

What is already known about the treatment

JR-441 – JR-441 is administered through weekly infusions, specifically designed for patients with mucopolysaccharidosis type IIIA (MPS IIIA). Currently, it is in the Phase I/II stage of clinical trials, where its safety and potential effectiveness are being evaluated. The main therapeutic indication for JR-441 is the treatment of MPS IIIA, a rare genetic disorder. At the molecular level, JR-441 works by targeting and breaking down the accumulated substances in the body that cause the symptoms of MPS IIIA. It is classified pharmacologically as an enzyme replacement therapy, aiming to supplement the deficient enzyme in affected individuals.

Investigated diseases

Mucopolysaccharidosis type IIIA (MPS IIIA) – This is a rare genetic disorder that affects the body's ability to break down certain complex carbohydrates called glycosaminoglycans. It is caused by a deficiency of the enzyme heparan N-sulfatase, leading to the accumulation of heparan sulfate in the body. This accumulation primarily affects the brain and central nervous system, resulting in progressive neurological symptoms. Children with MPS IIIA may initially develop normally but then experience a decline in cognitive and motor skills. Over time, they may also develop behavioral issues, sleep disturbances, and loss of speech. The progression of the disease varies, but it typically leads to severe neurological impairment.
Trial detailsLast updated 7 Oct 2026
Age0-17PhasePhase ITrial ID2024-517045-14-00Protocol codeJR-441-101Estimated enrolment15 patientsSponsorJcr Pharmaceuticals Co. Ltd.

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