---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-26-421079"
form_type: "8-K"
ticker: "RARE"
cik: "0001515673"
company_name: "Ultragenyx Pharmaceutical Inc."
filed_at: "2026-10-14T13:00:14+00:00"
generated_at: "2026-10-14T13:01:13.263403+00:00"
event_type: "m_and_a"
sentiment: "positive"
materiality_score: 0.7
calibrated_materiality_score: 0.7
confidence: "high"
source: SEC EDGAR
---

# Ultragenyx to sell FDA rare pediatric disease PRV for $203M in cash

## Summary
- Asset purchase agreement signed October 8, 2026; unnamed buyer pays $203 million in cash at closing.
- PRV was awarded by the FDA on September 17, 2026 with approval of FAYUVI (rebisufligene etisparvovec-hopf), also known as UX111.
- FAYUVI/UX111 treats pediatric patients with mucopolysaccharidosis type IIIA (MPS IIIA, Sanfilippo syndrome Type A).
- Closing subject to expiration or termination of the HSR antitrust waiting period; agreement to be filed with the FY2026 Form 10-K.
- Pact includes customary representations, warranties, covenants and indemnification provisions subject to limitations.

## SEC filing metadata
- accession: 0001193125-26-421079
- form_type: 8-K
- ticker: RARE
- cik: 0001515673
- company_name: Ultragenyx Pharmaceutical Inc.
- filed_at: 2026-10-14T13:00:14+00:00
- event_type: m_and_a
- sentiment: positive
- materiality_score: 0.7
- calibrated_materiality_score: 0.7
- confidence: high
- sec_items: 1.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1515673/000119312526421079/0001193125-26-421079-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1515673/000119312526421079/rare-20261008.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-26-421079
- JSON: https://secwatch.observer/filing/0001193125-26-421079.json
- Plain text: https://secwatch.observer/filing/0001193125-26-421079.txt

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