U.S. approves first treatment for Sanfilippo syndrome type A

The U.S. Food and Drug Administration has approved Fayuvi, the first treatment for Sanfilippo syndrome type A. The September 17 decision opens a treatment option for children who retain developmental abilities, targeting the disease’s effects on the brain and nervous system.

The ultra-rare genetic condition progressively damages the brain, causing children to lose skills such as speaking, learning and moving. Fayuvi, developed by Ultragenyx, is given as a single infusion into a vein. It delivers a working gene designed to help the body produce an enzyme that children with the disease lack.

According to the company, the main evidence compared 17 treated children with 27 untreated children from a separate study tracking the disease’s usual course. Treated children scored higher on a test of cognitive development. The comparison used an external group rather than children randomly assigned within the same trial, an important limitation when interpreting the results. Follow-up data extend to nearly eight years.

Treatment requires careful monitoring: elevated liver enzymes and reduced blood platelet counts were among the reported side effects. Ultragenyx expects supplies to reach specialist U.S. treatment centres within 30 to 60 days. A price had not been announced when the approval was reported.