---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-26-139084"
form_type: "8-K"
ticker: "RARE"
cik: "0001515673"
company_name: "Ultragenyx Pharmaceutical Inc."
filed_at: "2026-04-02T23:59:59+00:00"
generated_at: "2026-05-15T07:49:58.807889+00:00"
event_type: "regulatory"
sentiment: "positive"
materiality_score: 0.65
calibrated_materiality_score: 0.65
confidence: "high"
source: SEC EDGAR
---

# FDA accepts resubmitted BLA for UX111 gene therapy; PDUFA date Sept 19, 2026

## Summary
- FDA accepted for review resubmitted BLA for UX111 (rebisufligene etisparvovec) AAV9 gene therapy.
- UX111 is intended for Sanfilippo syndrome Type A (MPS IIIA) under accelerated approval pathway.
- PDUFA action date set for September 19, 2026.
- No new safety or efficacy data disclosed; review outcome remains uncertain.

## SEC filing metadata
- accession: 0001193125-26-139084
- form_type: 8-K
- ticker: RARE
- cik: 0001515673
- company_name: Ultragenyx Pharmaceutical Inc.
- filed_at: 2026-04-02T23:59:59+00:00
- event_type: regulatory
- sentiment: positive
- materiality_score: 0.65
- calibrated_materiality_score: 0.65
- confidence: high
- sec_items: 8.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1515673/000119312526139084/0001193125-26-139084-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1515673/000119312526139084/rare-20260402.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-26-139084
- JSON: https://secwatch.observer/filing/0001193125-26-139084.json
- Plain text: https://secwatch.observer/filing/0001193125-26-139084.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.