A drug used to increase bone mass in certain patients with breast cancer or prostate cancer who have a high risk of breaking bones. It is also used to treat osteoporosis in men and postmenopausal women who have a high risk of breaking bones. Prolia binds to a protein called RANKL, which keeps RANKL from binding to another protein called RANK on the surface of certain bone cells, including bone cancer cells. This may help keep bone from breaking down and cancer cells from growing. Prolia contains the active ingredient denosumab. It is a type of monoclonal antibody.