Denosumab delayed or prevented skeletal-related events (SREs) better than zoledronic acid, according to a study comparing the two agents in patients with breast cancer and bone metastases.
Stopeck and colleagues (J Clin Oncol. November 8, 2010. Epub ahead of print) randomized 2046 patients to either subcutaneous denosumab 120 mg and intravenous placebo or intravenous zoledronic acid 4 mg adjusted for creatinine clearance and subcutaneous placebo every 4 weeks. All patients were strongly recommended to take daily calcium and vitamin D supplements.
The researchers found that denosumab was superior to zoledronic acid in delaying time to first on-study SRE (HR, 0.82; 95% CI, 0.71-0.95; P = .01; superiority) and time to first and subsequent (multiple) on-study SREs (rate ratio, 0.77; 95% CI, 0.66-0.89; P = .001). The two agents, however, fared similarly in overall survival, disease progression, and rates of adverse events.
With denosumab’s avoidance of renal toxicity and acute phase reactions, the agent could be preferable to zoledronic acid for patients with chronic kidney disease.
The researchers concluded that with the convenience of a subcutaneous injection and no need for renal monitoring, denosumab represents a potential treatment option for patients with bone metastases.