Denosumab delays bone-related events The fully humanized monoclonal antibody denosumab inhibits the important regulator of osteoclast activity RANKL. a study by Stopeck et al. at the University of Arizona showed that in patients with bone metastases from breast cancer, denosumab was superior to zoledronic acid in delaying or preventing bone-related events (SRE, predefined as pathological fractures, bone radiotherapy or bone surgery, or spinal cord compression) than zoledronic acid: the time to first SRE was delayed in the denosumab group (1026 patients) compared with the zoledronic acid group (1020 patients) [not reached vs. 806 days, risk ratio (HR) = 0.82; P = 0.01], and the time to first and subsequent SRE was also delayed in the study (HR = 0.77; P = 0.001). The incidence of adverse events and serious adverse events was similar and consistent with previous reports in both groups. Therapeutic monoclonal antibodies include murine, chimeric, human and fully human, only fully human does not contain murine proteins and does not cause rejection in humans. denosumab is a fully human monoclonal antibody that is involved in bone resorption and increases bone mineral density by inhibiting RANKL, a regulator of osteoclast activity. This trial has an advantage over zoledronic acid in delaying and reducing bone-related events in patients with bone metastases from breast cancer. As we know, in the clinical trial of ABCSG12, zoledronic acid not only increased bone density and reduced the incidence of bone metastases, but also reduced the incidence of distant metastases with a survival benefit, with a significant 36% prolongation of DFS in the group with the addition of zoledronic acid. Therefore, the positioning of the two treatment indications is different. denosumab is mainly positioned in the treatment of osteoporosis and prevention of fracture occurrence, while zoledronic acid is used to prevent and treat bone metastasis in addition to treating osteoporosis, and there are clinical trials used to add zoledronic acid to chemotherapy at the same time to increase the efficacy, such as AZURE, SUCCESS, SWOG 307 clinical trials, etc. We are looking forward to The results of these clinical trials, if further validated to increase the effect of DFS, will be its unique therapeutic effect.