A drug used to prevent or treat certain bone problems. Under the brand name Xgeva, it is used to prevent broken bones and other bone problems caused by solid tumors that have metastasized (spread) to bone. Under the brand name Prolia, it is used to treat osteoporosis (a decrease in bone mass and density) in postmenopausal women who have a high risk of breaking bones. Denosumab binds to a protein called RANKL, which keeps RANKL from binding to another protein called RANK on the surface of certain bone cells. This may help keep bone from breaking down. Denosumab is a type of monoclonal antibody. Also called AMG 162, Prolia, and Xgeva.