Six-year-old Roran Jaskulski of New Berlin just became the face of a medical first. Children’s Wisconsin says it is the first hospital in the United States to give Avlayah, a newly FDA approved therapy engineered to reach the brain, to a child with Hunter syndrome.
Roran has the neuronopathic form of the rare disease, which can rob children of speech, mobility and other hard-won skills. Clinicians say the weekly infusion is designed to halt or even reverse that neurodegeneration. For Roran’s mother, Kylie Jaskulski, the chance to start treatment feels like “extra time” with her son.
As reported by FOX6 Milwaukee, the infusions were given at Children’s Wisconsin’s Milwaukee campus, where clinicians including Dr. Michael Finkel helped build the program after federal regulators cleared the drug. The station reports that Children’s Wisconsin currently has three patients receiving Avlayah through its new program.
FDA Approval And What Sets Avlayah Apart
The U.S. Food and Drug Administration granted accelerated approval to Avlayah (tividenofusp alfa-eknm) on March 25, 2026, for the treatment of neurologic manifestations of Hunter syndrome, according to the FDA. Regulators based that decision on large reductions in cerebrospinal fluid heparan sulfate, a surrogate biomarker that is reasonably likely to predict clinical benefit.
The agency also noted that Avlayah is the first enzyme replacement approach designed to cross the blood brain barrier, a key distinction for a condition that affects the brain as well as the rest of the body.
Early Trial Data And The Science
In an international Phase 1/2 study published in The New England Journal of Medicine, researchers reported substantial and sustained drops in cerebrospinal fluid heparan sulfate among children who received Avlayah. Many participants also showed signs of stabilized or improved adaptive behavior scores.
Those biomarker and clinical signals provided the foundation for the FDA’s accelerated approval and helped convince clinicians to begin offering the therapy to eligible pediatric patients now that it is commercially available.
What Families Can Expect
Denali Therapeutics, the company that developed Avlayah, describes it as an intravenous enzyme replacement given as a weekly infusion. In company briefings, management has said that patients who start as children are expected to stay on therapy as they grow up and that “patients will stay on drug throughout life,” according to Denali Therapeutics.
Parents and clinicians who spoke with reporters say the logistics of weekly infusions take planning, but they see the effort as worthwhile. Roran’s mother, Kylie, told FOX6 Milwaukee that getting her son started on the treatment feels like getting more time with him.
The Disease In Brief
Hunter syndrome, also known as mucopolysaccharidosis type II, is a rare X linked lysosomal disorder in which complex sugar waste products build up in cells and gradually damage organs and the brain. The neuronopathic form is associated with early developmental regression.
Experts note that children with this neuronopathic presentation often lose skills during childhood and frequently have shortened life spans, with many affected individuals living into the first or second decade of life, as outlined by GeneReviews.
For families across southeast Wisconsin, the combination of a newly FDA cleared brain penetrating enzyme replacement and a regional pediatric center already set up to deliver it represents a significant shift in what care can look like. Hospital officials say they will follow treated children closely and plan to share outcomes as longer term data come in.
