Denosumab is a monoclonal antibody. Monoclonal antibodies are made to target and destroy only certain cells in the body. This may help to protect healthy cells from damage. The Xgeva brand of denosumab is used to prevent bone fractures and other skeletal conditions in people with tumors that have spread to the bone. Xgeva is not for use in people with multiple myeloma (bone marrow cancer). Xgeva is also used to treat giant cell bone tumor in adults and teenagers with fully matured bone structure. This medication guide provides information about the Xgeva brand of denosumab. Prolia is another brand of denosumab used to treat osteoporosis in postmenopausal women who have high risk of bone fracture. Denosumab may also be used for purposes not listed in this medication guide.