Ultragenyx wins first-ever FDA approval in Sanfilippo syndrome type A

The US FDA has cleared Fayuvi (rebisufligene etisparvovec), a one-time gene therapy from USA-based rare disease specialist Ultragenyx Pharmaceutical (Nasdaq: RARE), as the first approved treatment for children with mucopolysaccharidosis type IIIA, better known as Sanfilippo syndrome type A. The decision was announced on September 17, two days ahead of the agency's target action date.

MPS IIIA is an inherited lysosomal storage disease in which a missing enzyme, sulfamidase, allows the sugar molecule heparan sulfate to build up inside cells. Children develop normally at first, then lose language, thinking and movement skills. Ultragenyx puts the affected population at roughly 3,000 to 5,000 patients in commercially accessible geographies, with a median life expectancy of 15 years.