---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-26-357185"
form_type: "8-K"
ticker: "RARE"
cik: "0001515673"
company_name: "Ultragenyx Pharmaceutical Inc."
filed_at: "2026-08-19T21:24:44+00:00"
generated_at: "2026-08-19T21:26:47.484991+00:00"
event_type: "regulatory"
sentiment: "positive"
materiality_score: 0.85
calibrated_materiality_score: 0.85
confidence: "high"
source: SEC EDGAR
---

# Ultragenyx wins FDA accelerated approval for GENGLYCOS (DTX401) in GSDIa

## Summary
- FDA granted accelerated approval for GENGLYCOS (pariglasgene brecaparvovec-opnr) in GSDIa patients aged 8+.
- Approval based on Phase 3 GlucoGene: 46 participants, cornstarch requirement reduction at Week 48 (p<0.001).
- Efficacy data from 44 mITT (DTX401 n=20, placebo n=24); crossover followed to Week 96/144.
- Post-marketing DMP: 2-year data from 50 treated and 20 control patients; 10-year total follow-up.
- Control group consists of patients with anti-AAV8 antibodies ineligible for treatment.

## SEC filing metadata
- accession: 0001193125-26-357185
- form_type: 8-K
- ticker: RARE
- cik: 0001515673
- company_name: Ultragenyx Pharmaceutical Inc.
- filed_at: 2026-08-19T21:24:44+00:00
- event_type: regulatory
- sentiment: positive
- materiality_score: 0.85
- calibrated_materiality_score: 0.85
- confidence: high
- sec_items: 8.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1515673/000119312526357185/0001193125-26-357185-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1515673/000119312526357185/rare-20260819.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-26-357185
- JSON: https://secwatch.observer/filing/0001193125-26-357185.json
- Plain text: https://secwatch.observer/filing/0001193125-26-357185.txt

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