Ultragenyx resubmitted its Biologics License Application (BLA) for UX111, an AAV9 gene therapy for Sanfilippo syndrome type A (MPS IIIA), on January 30, 2026.1246
The resubmission addresses a July 2025 Complete Response Letter (CRL) concerning manufacturing issues and includes long-term clinical data on neurologic benefits, CSF heparan sulfate biomarkers, and safety.12345
FDA granted Priority Review; expects up to 6-month review with PDUFA action date in Q3 2026.23456
If approved, UX111 would be the first therapy specifically for Sanfilippo syndrome type A.1256
Original BLA filed early 2025, received Priority Review in February 2025 before CRL.245
Sources:
1. https://simplywall.st/stocks/us/pharmaceuticals-biotech/nasdaq-rare/ultragenyx-pharmaceutical/news/ultragenyx-bla-resubmission-puts-ux111-and-rare-valuation-in/amp
2. https://curesanfilippofoundation.org/2026/01/ultragenyx-resubmits-ux111-to-fda-for-accelerated-approval-of-sanfilippo-type-a/
3. https://www.nasdaq.com/articles/ultragenyx-pharmaceutical-resubmits-bla-ux111-aav9-gene-therapy
4. https://www.lqventures.com/lucid-diligence-brief-ultragenyx-ux111-bla-resubmission/
5. https://www.stocktitan.net/sec-filings/RARE/8-k-ultragenyx-pharmaceutical-inc-reports-material-event-6355e02fde79.html
6. https://www.sec.gov/Archives/edgar/data/1515673/000119312526030590/rare-20260130.htm