- Fayuvi is a one-time intravenous gene therapy that uses a modified non-infectious adeno-associated virus serotype 9 (AAV9) to deliver a working copy of the SGSH gene, enabling cells to produce the missing sulfamidase enzyme and break down heparan sulfate in lysosomes.
- In an open-label, single-arm, multicenter study in patients aged 2 to 5 years, Fayuvi-treated children maintained or improved cognitive function versus an untreated historical control cohort, diverging from the expected natural course of plateau and decline.
- Common adverse reactions in more than 5% of patients were liver enzyme (AST) increases, nausea and vomiting, fever, decreased appetite, decreased white blood cell and platelet counts, and increased amylase; warnings include thrombotic microangiopathy and the long-term AAV integration risk.
- Fayuvi received orphan drug, fast track, and breakthrough therapy designations, and the FDA granted approval to Ultragenyx Pharmaceutical, Inc.
Quotes
“The approval of Fayuvi marks a historic moment for children and families living with MPS IIIA, which is a disease that has, until now, offered no approved treatment to alter its devastating course”
“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.”
“Achieving meaningful neurodevelopmental benefit through a single intravenous administration represents a significant scientific milestone — demonstrating that systemic AAV9-mediated gene delivery can reach the central nervous system at therapeutically relevant levels in pediatric patients.”