Wilson disease is a rare genetic disorder that causes excess copper to be stored in the body. The disease is progressive, and if left untreated, can cause liver disease, brain injury, and premature death. Learn how gene therapy may target the cause of disease to slow or stop its progression, along with helpful information on clinical trials, and staying informed.
About Wilson Disease
Cause of disease - The ATP7B gene provides instructions to cells to produce a transporter protein that moves excess copper out of the liver. Copper is a vital element that supports the nervous system, immune system and helps to make blood cells. Typically, copper is absorbed from the foods we eat. Wilson disease is caused by mutations (e.g. changes or variants) in this ATP7B gene. Therefore, the transporter protein does not function properly. This means its activity level is low or absent, which allows excess copper to stay in the liver, build up and become toxic throughout the body.
Symptoms – Children and young adults with Wilson disease often develop liver dysfunction as the initial medical issue. A person with liver disease can develop fatigue and a yellow discoloration of the skin. There are a small number of people with the disease that will experience severe liver failure. But in some cases, liver disease may progress silently while a person initially develops the first symptoms from the effect on the brain, such as tremors and difficulty speaking or moving. A portion of individuals may present with liver disease, while the other portion may present with brain complications.
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Gene Therapy Approach
Gene therapy aims to be a one-time treatment that delivers a working ATP7B gene into cells to produce working transporter proteins. The goal is to restore proper liver function and remove excess copper. By clearing copper from the bloodstream the toxic effect on other organs, like the brain, should be reduced. An in-vivo approach is being studied, meaning the gene therapy is delivered directly into the body to target liver cells. This investigational therapy is being given as an intravenous (into a vein) infusion.
A viral vector is used as a carrier to deliver the working gene. Scientists know that viruses are good at getting into cells, so they have learned how to safely use this ability to deliver working genes. But don’t worry, the viral genes are removed, so only therapeutic (intended) genes are delivered. Think of a viral vector as an envelope with a message inside. The harmful letter that could cause disease is taken out of the envelope and replaced with a new gene that has a specific message for the cells. Once delivered, the working gene gives instructions to liver cells to make the transporter protein. The goal is to prevent, slow, or stop disease progression.
Treatment Pipeline
There is an active gene therapy clinical trial for Wilson disease, while other research is still in preclinical studies. Clinical trials are part of a required research process to understand the way a drug or treatment will interact with the human body and whether it is safe and effective. Preclinical studies are an even earlier stage of research to confirm the safety and effectiveness of a treatment in animal or cell-based models before proceeding with a human clinical trial study.
This research and development for Wilson disease is being done by companies including Vivet Therapeutics/Pfizer, and Ultragenyx Pharmaceutical. To stay up to date on open clinical trials in the U.S. or globally, visit the ASGCT Clinical Trials Finder and search using the "diagnosis" filter.
Participating in a Clinical Trial
For some, the effects of Wilson disease can be prevented or treated by lifelong medical treatments, that are often given daily to lower copper in the body to nontoxic levels. However, these available treatments are not effective for everyone, so some may consider gene therapy as an option. It is important to be informed when entering a clinical trial, so we introduce some key points below. Go to the considering a clinical trial page for more information and resources to help guide you.
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Eligibility - Eligibility for a trial is based on strict inclusion and exclusion criteria. These are specific factors that determine whether a person can or cannot join a clinical trial. This is an important way for researchers to understand if the gene therapy is working properly and to ensure participant safety. These criteria may include factors such as age, physical ability, medical history, and more. Speak with a healthcare provider or a member of the clinical trial research team to help determine if you or your child may be eligible for a clinical trial.
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Risks – As with any medical intervention, there are risks that need to be carefully considered. Before participating in a clinical trial, a member of the research team should review any potential risks and benefits with the patient or caregiver. Therapies being studied in clinical trials are not a guaranteed cure and cannot guarantee beneficial results. There is always a chance that the investigational treatment may not work. In the event a person is not satisfied with the outcome, the person cannot receive another dose of the gene therapy. In addition, participating in a clinical trial may prevent future participation in other trials or from receiving other types of treatments. Gene therapy can be alteration for the lifetime, so people should be aware that there could be long term effects (both good or bad) that are unknown at this time.
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Benefits – Participating in a trial may offer many potential benefits compared to not receiving any form of intervention for a fatal disease. Gene therapy aims to be a one-time treatment with lasting positive effects to slow or stop disease progression for a lifetime, but again there is no guarantee. This is possible because it targets the cause of disease, which is a faulty gene. If gene therapy is received earlier in the course of disease, it has the potential to stop any damage before it occurs.
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Long-term follow up – It is the patient’s responsibility to comply with the long-term follow-up of a trial. FDA guidelines require the clinical trial research team to monitor safety and potential long-term effects of a gene therapy. Follow-up may require in-person appointments that vary in frequency and location, or completion of mailed packets with response forms. The need for long-term data collection for a gene therapy trial can last up to 15 years—another reason to consider all outcomes and responsibilities that come with committing to a clinical trial. There are a limited number of participants in trials so a lack of attendance at follow-up appointments leads to not enough study data. This could negatively affect FDA approval of a new drug and thereby limit access to the therapy by patients who did not participate in the clinical trial.
Access
At this time, we do not know if or when gene therapies will be approved by the FDA and commercially available for people living with Wilson disease. The overall process may take several more years, until it is deemed safe and effective by the FDA.
Stay Informed
There are many patient advocacy organizations to follow or get involved with. They work hard to fund research and advocate for patient and family needs. They are also a great way to connect with others affected by the disease if you are looking for support and advice.
Was this information helpful? If so, please feel free to share these resources by referencing the Wilson disease media kit!