Denosumab (Denosumab) Denosumab is a monoclonal antibody that inhibits RANKL and reduces the activity of osteoclasts. In a randomized, double-blind, placebo-controlled phase III clinical study, 1432 patients with CRPC without metastases but at high risk of bone metastases were divided 1:1 into a denosumab group (120 mg/q4w, subcutaneously) or a placebo group, and the primary endpoint of the study was survival without bone metastases or death from any cause. Results found a 4.2-month delay in the onset of bone metastases in patients treated with denosumab compared with those receiving placebo (HR: 0.85, p=0.028), but no improvement in patient OS. The main adverse effects of denosumab treatment were osteonecrosis of the jaw (5%) and hypocalcemia (2%).