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Study on the Safety and Effects of UX701 Gene Therapy for Adults with Wilson Disease

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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 Wilson disease, a rare genetic disorder that affects the body's ability to regulate copper. The study is testing a new treatment called UX701, which is a type of gene therapy. Gene therapy involves using a specially designed virus to deliver a modified version of a gene into the body. In this case, the virus is designed to help correct the copper metabolism in people with Wilson disease by transferring a modified protein known as ATP7B.

The purpose of the study is to evaluate the safety and effects of UX701 in adults with Wilson disease. Participants will receive either the gene therapy or a placebo. The study will be conducted in two stages. In the first stage, the focus will be on determining the safest dose of UX701 and understanding its effects over a period of 52 weeks. The second stage will compare the effects of UX701 with a placebo, particularly looking at how well it helps regulate copper levels in the body.

Throughout the study, participants will undergo regular assessments to monitor their health and the effects of the treatment. This includes checking copper levels in the body and evaluating any changes in their current medication for Wilson disease. The study aims to provide valuable information on the potential benefits and risks of using UX701 as a treatment for Wilson disease.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial assessment

    Upon joining the study, an initial assessment will be conducted to confirm eligibility. This includes reviewing your medical history and current treatment for Wilson disease.

    You will undergo tests to measure copper levels in your body, including a 24-hour urine collection.

  2. Step 2

    Treatment allocation

    You will be randomly assigned to receive either the study treatment, UX701, or a placebo. This process is double-blind, meaning neither you nor the study team will know which treatment you are receiving.

    The study treatment involves a single dose administered through an intravenous infusion.

  3. Step 3

    Medication regimen

    If you are receiving the study treatment, you will be given a single intravenous dose of UX701, which is a gene therapy designed to help regulate copper levels in your body.

    You will continue your current medication regimen for Wilson disease, which may include copper chelators or zinc therapy, unless advised otherwise by the study team.

  4. Step 4

    Regular monitoring

    Throughout the study, you will have regular visits to monitor your health and the effects of the treatment. This includes blood tests, urine tests, and assessments of your copper levels.

    You will be asked to report any side effects or changes in your health during these visits.

  5. Step 5

    Follow-up assessments

    At the end of the study period, which lasts up to 52 weeks, a comprehensive assessment will be conducted to evaluate the treatment's impact on your copper regulation.

    This will include a final 24-hour urine collection and other tests to measure copper levels and liver function.

  6. Step 6

    Long-term follow-up

    After the main study period, you may be asked to participate in long-term follow-up assessments to monitor your health and the lasting effects of the treatment.

    These follow-ups are important to ensure your safety and to gather additional data on the treatment's effectiveness.

Who can join the trial?

6 criteria

  • Individuals must be 18 years of age or older at the time they agree to participate in the study.
  • Must have a confirmed diagnosis of Wilson disease, which is verified by specific genetic tests showing changes in the ATP7B gene.
  • Must have been on ongoing treatment with copper chelators (medications like penicillamine or trientine) and/or zinc therapy for at least 12 months before the study starts, with no changes in medication or dosage for at least 6 months before the study starts.
  • Must have stable Wilson disease, shown by consistent 24-hour urinary copper levels during the screening period (two test results within 30% of each other, taken about 4 weeks apart).
  • Must have been following a diet restricting high-copper foods for at least 12 months before the study and continue this diet during the study.
  • Must be willing and able to follow all study procedures and requirements, which include frequent blood tests, collecting all urine over a 24-hour period, completing questionnaires about their health, and participating in long-term follow-up.

Who cannot join the trial?

8 criteria

  • Patients who do not have Wilson disease cannot participate.
  • Patients who are not within the specified age range cannot participate.
  • Patients who are not willing to follow the study procedures cannot participate.
  • Patients who have other serious health conditions that might interfere with the study cannot participate.
  • Patients who are pregnant or breastfeeding cannot participate.
  • Patients who have participated in another clinical trial recently cannot participate.
  • Patients who have allergies to the study medication cannot participate.
  • Patients who are unable to give informed consent cannot participate.
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Investigated drugs

UX701 is a gene therapy treatment being studied for its potential to help people with Wilson disease. Wilson disease is a condition where the body cannot properly get rid of excess copper, leading to harmful copper buildup. This treatment uses a special virus to deliver a healthy copy of the gene responsible for copper regulation into the patient's liver cells. The goal is to help the body manage copper levels better, reducing the need for other medications that patients with Wilson disease usually take. The study is looking at how safe this treatment is and how well it works in controlling copper levels in the body.

What is already known about the treatment

UX701 – UX701 is administered through an intravenous (IV) infusion, meaning it is delivered directly into the bloodstream. Currently, this medication is being studied in clinical trials for its potential use in treating Wilson disease, a genetic disorder that causes excessive copper accumulation in the body. The main therapeutic goal of UX701 is to help regulate copper levels in the body, which it aims to achieve by using a gene transfer method to correct the underlying genetic defect. Pharmacologically, UX701 is classified as a gene therapy, which works at the molecular level by introducing a healthy copy of the gene responsible for copper regulation, thereby helping to restore normal copper metabolism.

Investigated diseases

Wilson disease – Wilson disease is a genetic disorder that leads to excessive accumulation of copper in the body, primarily affecting the liver and brain. The disease progresses as copper builds up in the liver, causing liver damage and potentially leading to liver failure. Over time, copper can also accumulate in the brain, resulting in neurological symptoms such as tremors, difficulty speaking, and problems with coordination. As the disease advances, psychiatric symptoms like depression and anxiety may develop. The progression of Wilson disease varies among individuals, with some experiencing rapid deterioration while others have a slower course. Early detection and management are crucial to prevent severe complications.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase I/IITrial ID2022-502873-40-00Protocol codeUX701-CL301Estimated enrolment78 patientsSponsorUltragenyx Pharmaceutical Inc.

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