FAYUVI is a highly anticipated, first-ever treatment option with the potential to stop or slow the devastating, irreversible neurologic progression and loss of function associated with Sanfilippo syndrome Type A

Ultragenyx’s UltraCare® program will support access, and commercial product is expected to be available to ship to Qualified Treatment Centers within 30-60 days

FAYUVI marks the second gene therapy approval, and sixth FDA approval overall, for Ultragenyx

The Company received a Priority Review Voucher upon FAYUVI approval

Ultragenyx to Host Conference Call on September 17, 2026 at 5:30 p.m. Eastern Time

NOVATO, Calif., Sept. 17, 2026 (GLOBE NEWSWIRE) -- Ultragenyx Pharmaceutical Inc. (NASDAQ:RARE) today announced that the U.S. Food and Drug Administration (FDA) granted standard full approval of FAYUVI™ (rebisufligene etisparvovec-hopf), also known as UX111, for the treatment of pediatric patients with mucopolysaccharidosis type IIIA (MPS IIIA, Sanfilippo syndrome Type A). FAYUVI is the first-ever FDA-approved treatment for Sanfilippo syndrome Type A, a progressive and fatal neurodegenerative disease, and the second gene therapy approval for Ultragenyx. The Company received a Priority Review Voucher upon this approval.