09:21 AM EDT, 07/10/2025 (MT Newswires) -- Health care stocks were mixed premarket Thursday as the Health Care Select Sector SPDR Fund ( XLV ) was 0.1% lower and the iShares Biotechnology ETF (IBB) was recently up 0.6%.

Ultragenyx (RARE) and Mereo BioPharma ( MREO ) said the placebo-controlled portion of a pivotal phase 3 study of UX143, or setrusumab, for osteogenesis imperfecta is advancing to final analysis as planned, with data expected by year-end. Ultragenyx CEO Emil Kakkis said the partners "had hoped to be able to stop the study early." Shares of Ultragenyx Pharmaceutical ( RARE ) were down more than 20% and Mereo BioPharma ( MREO ) shares were more than 31% lower pre-bell.

Nurix Therapeutics ( NRIX ) shares were up more than 10% after the company reported a narrower fiscal Q2 net loss as revenue more than tripled during the period.

Soleno Therapeutics ( SLNO ) shares were down more than 1% after the company proposed to offer and sell $200 million of common shares in an underwritten public offering.