On September 17, 2026, 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.
“For families living with Sanfilippo syndrome type A, the trajectory of this disease is heartbreaking — children who develop normally in their earliest years facing a relentless regression with no approved treatment to slow it. Parents and clinicians have been waiting far too long for an option,” said Karim Mikhail, B. Pharm., M.S., Director of the Center for Biologics Evaluation and Research in FDA’s announcement. “Today’s approval of Fayuvi is a meaningful step forward — not only for these children and their families, but for the promise of gene therapy to address rare and devastating diseases where the need for safe and effective treatment is the most urgent.”
“The approval of FAYUVI reflects years of research from scientists and developers, as well as unwavering support from so many families and patient organizations in the face of a devastating, universally fatal disease with no treatment options. This is a historic milestone for a community that has waited far too long, but has never given up hope,” said Emil D. Kakkis, M.D., Ph.D., chief executive officer and president of Ultragenyx. “We recognize the profound urgency of making this therapy available to families, and our focus now is on supporting timely access in the U.S. as we work closely with treatment centers and payers to support families on the gene therapy treatment journey. FDA approval is an important first step toward our long-term goal to bring this treatment option to families of children with Sanfilippo syndrome Type A around the world.” Read the statement by Ultragenyx.
Information about accessing FAYUVI
Read the complete prescribing information:
https://www.ultragenyx.com/wp-content/uploads/2026/09/UX111-USPI-FDA-Approved-9-17-2026.pdf