---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-23-256537"
form_type: "8-K"
ticker: "RARE"
cik: "0001515673"
company_name: "Ultragenyx Pharmaceutical Inc."
filed_at: "2023-10-16T23:59:59+00:00"
generated_at: "2026-06-09T23:16:47.979649+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.85
calibrated_materiality_score: 0.85
confidence: "high"
source: SEC EDGAR
---

# Ultragenyx reports prelim Q3 rev $96-100M; UX143 cuts fractures 67% in Phase 2

## Summary
- Prelim Q3 total rev $96-100M; Crysvita $74-76M (impacted by inventory shift to KKC); cash $525M.
- Setrusumab (UX143) cut annualized fracture rate 67% (p=0.042) in Phase 2; BMD +13-16% at 6 months.
- GTX-102 for Angelman: clinically meaningful improvements vs natural history; no new SAEs since Nov 2022.
- UX701 for Wilson: 4/5 low-dose patients tapering off chelators; 2 completely off standard therapy.
- Gene therapy: DTX401 Phase 3 fully enrolled; UX111 fully enrolled; DTX301 enrollment expected H1 2024.

## SEC filing metadata
- accession: 0001193125-23-256537
- form_type: 8-K
- ticker: RARE
- cik: 0001515673
- company_name: Ultragenyx Pharmaceutical Inc.
- filed_at: 2023-10-16T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.85
- calibrated_materiality_score: 0.85
- confidence: high
- sec_items: 2.02, 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1515673/000119312523256537/0001193125-23-256537-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1515673/000119312523256537/d548890d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-23-256537
- JSON: https://secwatch.observer/filing/0001193125-23-256537.json
- Plain text: https://secwatch.observer/filing/0001193125-23-256537.txt

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