Springfield family gets approval for daughter to receive new treatment

For Abby and Steven Milburn, the promise of a new treatment comes down to something every parent treasures: more time with their child.

More time for their daughter, Lottie, to hold onto the skills she has learned. More time with her three younger siblings. More time to enjoy being a little girl.

The Springfield couple learned Oct. 5 that Lottie, who is almost 6, passed an antibody test needed to receive a newly approved gene therapy for Sanfilippo syndrome type A, a rare, devastating genetic disease. They are now working with their insurance company toward getting her treated at St. Louis Children’s Hospital.

“We just learned that she is eligible,” Abby said of Lottie during an Oct. 6 interview with Illinois Times. 

For a family that last year was searching for a way to obtain an experimental treatment, it is a hopeful turning point. The medication they wanted for their daughter now has federal approval, and a crucial test has brought her another step closer to receiving it.

The Food and Drug Administration approved Fayuvi, previously known as UX111, on Sept. 17. It is the first FDA-approved treatment for children with Sanfilippo syndrome type A. The approval covers pediatric patients with preserved neurodevelopmental function.

Sanfilippo progressively damages the brain and nervous system, robbing children of cognitive, language and other developmental abilities. Fayuvi uses a modified, noninfectious virus to deliver a working copy of a gene into the patient’s cells, enabling them to produce an enzyme that is missing or deficient. That enzyme helps break down heparan sulfate, a substance whose harmful buildup drives the disease.

For the Milburns, the science carries a deeply personal hope: preserving their daughter’s abilities and giving her a better, longer life.

“We’re hoping that it will slow and possibly stop the progression of the disease,” Abby said.

Because Lottie is approaching 6, her parents are cautious about how much the treatment can accomplish. They hope it will help her hold onto her skills and give the family more time together with a better quality of life.

Lottie has not yet received the infusion, and her response remains to be seen. But her parents now have an approved treatment to pursue.

When Illinois Times first reported on the family in July 2025, the Milburns were investigating ways to obtain treatment before FDA approval. Lottie had been diagnosed that April. She also has Down syndrome, which her parents said complicated the search for an explanation when she began losing skills.

Abby knew to ask about Sanfilippo because a cousin had the disease. Without that family experience, she said, she might not have known what question to raise.

“The regression … was, like, the piece that really worried us,” she said.

The months that followed became a race against a disease that does not wait for paperwork.

U.S. Rep. Nikki Budzinski, D-Springfield, said her office wrote to the FDA on the family’s behalf, urging action on the therapy. She described the urgency of helping Lottie reach treatment while she could still benefit.

“The uniqueness of this rare disease is that time is not on our side,” Budzinski said.

The congresswoman said working with the Milburns also prompted her to join the House Rare Disease Caucus, broadening her advocacy to other families facing similar struggles.

“I hope that this can be just a … positive step in the right direction,” she said. “There’s more to come.”

The Milburns expect Lottie’s treatment to be a one-time intravenous infusion followed by months of monitoring. Her care team in St. Louis is preparing to offer the therapy, they said.

The FDA reported that treated children in a clinical study maintained or improved cognitive function compared with an untreated historical comparison group. The infusion requires medical supervision and follow-up, including corticosteroid treatment for at least eight weeks afterward.

For other families, the approval creates a treatment option where none previously existed. It also makes early diagnosis an increasingly urgent goal.

The Milburns want screening for Sanfilippo to become more widely available to newborns, giving families a chance to identify the condition before children begin losing skills. Budzinski said she is co-sponsoring legislation intended to expand opportunities for early identification of rare diseases.

“To get that added to the newborn screening would be huge,” Abby said.

The family also hopes this milestone will encourage progress on therapies for other forms of Sanfilippo and other rare diseases. Those treatments will need their own evidence and approvals, but the Milburns see reason for families to keep hoping.

For now, their attention is on insurance arrangements, the hospital and the next step toward Lottie’s infusion.

A year ago, they were fighting for the chance to try. Today, that chance is closer — carrying the possibility of more childhood for Lottie and more time for the people who love her.