Ultragenyx Pharmaceutical announced phase‑3 failures in two brittle‑bone disease trials and signaled a significant cost‑cutting program in response. The company will restructure spending and prioritize remaining pipeline assets following the late‑stage disappointments that removed expected near‑term value drivers. Management framed the reductions as necessary to preserve cash runway and refocus on programs with clearer regulatory paths, but investors will watch guidance and R&D reprioritization closely as the company recalibrates its strategy amid the setbacks. Clarification: brittle bone diseases (e.g., osteogenesis imperfecta) often require long‑term trials and significant investment; phase‑3 failures remove potential approval and revenue scenarios.