Ultragenyx hits record low after bone disease drug fails late-stage trials

Ultragenyx Pharmaceutical

29/12/2025 14:55

Updates

** Shares of Ultragenyx Pharmaceutical RARE.O plunge 44.9% to a record low of $19.07

** Stock set for worst day ever if losses hold

** RARE says its experimental drug for a type of genetic bone disease did not meet the main goal in late-stage studies

** The drug, setrusumab, was being developed for people with osteogenesis imperfecta, a rare genetic disorder that causes brittle bones

** While the studies did not achieve statistical significance on fracture reduction, both showed meaningful improvements in bone mineral density, a key indicator of bone strength - RARE

** Including session moves, stock down 54.2% YTD

 (Reporting by Siddhi Mahatole)

 ((siddhi.mahatole@thomsonreuters.com))