A clinical trial at the University of North Carolina led by Joseph Muenzer, MD, PhD, resulted in the U.S. Food and Drug Administration approving a new drug for Hunter syndrome, according to an April 1 announcement.
The approval is significant for children and families affected by Hunter syndrome, a rare genetic disorder that previously had limited treatment options. The newly approved drug offers hope for slowing both brain and physical symptoms with a single infusion.
“I was just phenomenally excited when I heard that it got approved because we have a drug now that can treat both the brain disease and the physical disease with one infusion,” said Dr. Muenzer, Director of the Muenzer MPS Research and Treatment Center at UNC School of Medicine.
Kim Stephens, Executive Director of the center and mother to Cole—a patient who has been under Dr. Muenzer’s care for more than thirteen years—said she was relieved by the FDA’s decision. “This is his last chance, and I knew it was. This is it,” Stephens said. “I knew it was working because I would see the kids in the trial and, we were just watching it and watching it, and saying, ‘Is the approval coming in time for Cole?’ Because he was at that age when most boys with Hunter syndrome pass, and it did come, and Cole will be on it.”
The FDA approved Avlayah on March 25 as a first-of-its-kind treatment developed by Denali Therapeutics. The drug is designed to reach both brain and body tissues to slow progression of symptoms associated with Hunter syndrome. Initial results from UNC’s clinical trial were published in January 2026 in The New England Journal of Medicine with Dr. Muenzer as first author.
This marks what researchers describe as “the first major advance” in treating Hunter syndrome in two decades.
