Denosumab and bone metastases. No better than a bisphosphonate

The standard treatment used to prevent clinical repercussions of bone metastases from solid tumours consists of an intravenous bisphosphonate such as pamidronic acid. Denosumab,a monoclonal antibody injected subcutaneously, has been licensed in the European Union for use in this setting. Three double-blind randomised trials including a total of about 6000 patients showed no tangible difference between denosumab and zoledronic acid in terms of mortality, disease progression, quality of life, or pain. The authors resorted to a composite endpoint in order to demonstrate a statistically significant difference in favour of denosumab. Overall, toxicity was similar with denosumab and zoledronic acid in the 3 trials. Adverse effects that were more frequent with denosumab than with zoledronic acid included jaw osteonecrosis (1.8% versus 1.3%) and hypocalcaemia (9.3% versus 4.7%). However, renal failure was less frequent (2.6% versus 3.7%). Denosumab is administered subcutaneously and zoledronic acid by intravenous infusion. It is not known whether local and systemic reactions to administration are different. In practice, there is no tangible reason to choose denosumab rather than a bisphosphonate.