---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-26-062568"
form_type: "8-K"
ticker: "RARE"
cik: "0001515673"
company_name: "Ultragenyx Pharmaceutical Inc."
filed_at: "2026-02-23T23:59:59+00:00"
generated_at: "2026-05-16T01:08:18.361665+00:00"
event_type: "regulatory"
sentiment: "positive"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# FDA accepts Ultragenyx's BLA for DTX401 gene therapy for GSDIa with Priority Review, PDUFA Aug 23, 2026

## Summary
- FDA accepted Biologics License Application for DTX401 (pariglasgene brecaparvovec) to treat Glycogen Storage Disease Type Ia.
- Granted Priority Review; Prescription Drug User Fee Act (PDUFA) action date is August 23, 2026.
- DTX401 is an AAV-based gene therapy targeting a rare metabolic disorder with no approved therapies.
- BLA acceptance triggers regulatory milestone; company may be eligible for priority review voucher if approved.

## SEC filing metadata
- accession: 0001193125-26-062568
- form_type: 8-K
- ticker: RARE
- cik: 0001515673
- company_name: Ultragenyx Pharmaceutical Inc.
- filed_at: 2026-02-23T23:59:59+00:00
- event_type: regulatory
- sentiment: positive
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 8.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1515673/000119312526062568/0001193125-26-062568-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1515673/000119312526062568/rare-20260223.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-26-062568
- JSON: https://secwatch.observer/filing/0001193125-26-062568.json
- Plain text: https://secwatch.observer/filing/0001193125-26-062568.txt

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