What we know about the treatment
The treatment FAYUVI (UX111)
On 17 September 2026, the US FDA approved FAYUVI. It is the first approved treatment for Sanfilippo type A. This brings new hope for children and their families.
The total cost of Muk’s treatment, preparation, travel and accommodation is not yet known. That is why we are continuing to raise funds. Your donation helps make treatment accessible for Muk.
What does FAYUVI do?
FAYUVI is a one-time gene therapy given through an infusion. The treatment delivers a working copy of a gene into the body, enabling cells to produce the enzyme missing in Sanfilippo type A.
That enzyme helps break down harmful substances that would otherwise build up. In this way, the treatment addresses the cause of the disease.
What does the research show?
In children who were treated early, research showed that important skills were maintained and continued to develop. Comparable children without treatment lost skills.
The first treated children have now been followed for more than eight years. How much a child benefits also depends on the damage the disease has already caused.
What the FDA says about this
Doctors assess each child individually
The approval applies to children with Sanfilippo type A who retain important developmental skills. The FDA leaves this assessment to the treating doctor.
Her parents can describe what Muk still does and can do at home. Their experiences help build a clear picture of Muk; the medical assessment remains the doctor’s responsibility.
Within this indication, there is no fixed maximum age or developmental score that alone determines whether a child can be treated. This individual assessment is therefore an important next step for Muk.
Where we stand
Step by step towards treatment in America
We are in contact with a treatment centre in America and are working on Muk’s medical preparation.
Contact in America
We are discussing with the treatment centre what is needed to assess Muk.
Medical records
We are gathering Muk’s complete medical records for that assessment.
An important blood test
Muk needs to be tested for antibodies to AAV9, the virus used to deliver the gene therapy.
Follow Muk’s journey to America
On Instagram, we share the latest steps, new developments and personal updates.
Every donation still matters
Help Muk on her way to treatment
We do not yet know the combined cost of treatment, medical preparation, travel and accommodation. That is why we are continuing to raise funds. We want to be ready to act as soon as treatment becomes possible for Muk.
Donate for MukWant to know more about FAYUVI?
Here you can find official information about approval, research and preparation for treatment. These sources form the basis of the information on this page.
Updated on 9 October 2026