Abstract
Background: This study compared the effect of denosumab in delaying or preventing the skeletal related events (SREs) versus zoledronic acid in patients with advanced cancer with bone metastases.
Patients and methods: Patients classified into two groups, the first group (no=50 patients) received intravenous zoledronic acid 4mg every 4 weeks and the second group (no=50 patients) received subcutaneous denosumab 120mg every 4 weeks. The primary end point was time to first on-study SRE (defined as radiation to bone, surgery to bone, spinal cord compression, and pathologic fracture) and the second end point was time to first and subsequent on-study SRE (defined as an event occurred ≥21 days after the previous SRE) .
Results: Denosumab resulted in delaying time to first on-study SRE compared to zoledronic acid (26% versus 36%, 95% confidence interval [CI], 0.82 to 1.44; P<0.04). The median time to first on-study SRE was 21.9 month for denosumab versus 18.1 month for zoledronic acid (P<0.04). Denosumab reduced the subsequent on-study SREs (10% versus 16%, p<0.04). There is a significant difference between patients without SREs in both groups (64% versus 48%) at the end of study (P<0.04). Denosumab was found to be safer than zoledronic acid as regarding renal toxicity (2% versus 10%, P<0.04).
Conclusion: Denosumab was more efficacious in delaying and preventing the SREs in patients with advanced cancer with bone metastases compared to zoledronic acid. Therefore denosumab improved the quality of life (QOL) of patients.