Exhibit 99.1 Contacts Ultragenyx Pharmaceutical Inc. Investors Joshua Higa ir@ultragenyx.com Media Jess Rowlands media@ultragenyx.com Ultragenyx Reports First Quarter 2026 Financial Results and Corporate Update First quarter total revenue of $136 million, Crysvita® revenue of $93 million and Dojolvi® revenue of $18 million Reaffirm 2026 financial guidance, including total revenue of $730 million to $760 million and combined R&D and SG&A expenses to be flat to slightly down versus 2025; remain on path to pro ...