05:11 PM EDT, 07/09/2025 (MT Newswires) -- Ultragenyx (RARE) and Mereo BioPharma ( MREO ) said Wednesday that the placebo-controlled portion of a pivotal phase 3 study of UX143 (setrusumab) for osteogenesis imperfecta is advancing to final analysis as planned, with data expected by year-end.

The study's independent data monitoring committee affirmed that the candidate maintains an "acceptable safety profile," supporting continued dosing in both Orbit and Cosmic trials, according to a statement.

"While we had hoped to be able to stop the study early, we look forward to having results from both Orbit and Cosmic around the end of this year," said Ultragenyx CEO Emil D. Kakkis.

Final analyses will proceed after patients have completed at least 18 months of treatment.

Shares of Ultragenyx fell 27% and Mereo stock declined 40% in recent after-hours trading activity.