Ultragenyx has received Breakthrough Therapy Designation from the U.S. Food and Drug Administration for setrusumab as a treatment to reduce the risk of fracture associated with osteogenesis imperfecta Type I, III, or IV in patients 2 years of age and older.The FDA’s decision is based on preliminary clinical evidence including the positive 14-month results from the Phase 2 portion of the Orbit study, which demonstrated a rapid and clinically meaningful decrease in fracture rate in patients, and from the completed Phase 2b ASTEROID study. Breakthrough Therapy Designation aims to expedite the development and review of drugs that are intended to treat serious or life-threatening diseases and whose preliminary clinical evidence indicates that the drug may demonstrate substantial improvement on one or more clinically significant endpoints over existing therapies.