Ultragenyx stock sinks 42% after Phase 3 setrusumab miss; what RARE investors watch nextNEW YORK, December 29, 2025, 23:21 ET — Market closed
Ultragenyx Pharmaceutical Inc shares slid on Monday after the company said two late-stage studies of setrusumab for osteogenesis imperfecta missed their primary fracture-reduction goal, prompting plans for significant expense reductions. “We are surprised and disappointed by these results,” Chief Executive Emil Kakkis said. Shares last traded down 42.3% at $19.72 after the close, versus a prior close of $34.19, after swinging between $34.50 and $17.76 on volume of about 21.7 million shares. Stock Titan
