Effect of denosumab versus zoledronic acid in preventing skeletal-related events in patients with bone metastases by baseline characteristics

Background: Analyses of phase III trials showed that denosumab was superior to zoledronic acid (ZA) in preventing skeletal-related events (SREs) irrespective of age, history of SREs, or baseline pain status. This analysis assessed the risk of SREs across additional baseline characteristics. Patients and Methods: Patients (N Z 5543) from three phase III trials who had breast cancer, prostate cancer, or other solid tumours and one or more bone metastasis were included. Superiority of denosumab versus ZA in reducing risk of first SRE and first and subsequent SREs was assessed in subgroups defined by the Eastern Cooperative Oncology Group performance status (ECOG PS), bone metastasis location, bone metastasis number, visceral metastasis presence/absence, and urinary N-telopeptide (uNTx) level using Cox proportional hazards and AndersoneGill models. Subgroups except bone metastasis location were also assessed for each solid tumour type. Results: Compared with ZA, denosumab significantly reduced the risk of first SRE across all subgroups (hazard ratio [HR] ranges: ECOG PS, 0.79e0.84; bone metastasis location, 0.78e0.83; bone metastasis number, 0.78e0.84; visceral metastasis presence/absence, 0.80e0.82; uNTx level, 0.73e0.86) and reduced the risk of first and subsequent SREs in all subgroups (HR ranges: ECOG PS, 0.76e0.83; bone metastasis location, 0.78e0.84; bone metastasis number, 0.79e0.81; visceral metastasis presence/absence, 0.79e0.81; uNTx level, 0.74e0.83). Similar results were observed in subgroups across tumour types. Conclusion: Denosumab was superior to ZA in preventing SREs in patients with bone metastases from advanced cancer, regardless of ECOG PS, bone metastasis number, baseline visceral metastasis presence/absence, and uNTx leve

Superiority of denosumab to zoledronic acid for prevention of skeletal-related events : a combined analysis of 3 pivotal, randomised, phase 3 trials

Background: Patients with bone metastases from advanced cancer often experience skeletal-related events (SRE), which cause substantial pain and morbidity. Denosumab, a fully human monoclonal antibody that inhibits RANK Ligand (RANKL), is a novel bone-targeted agent with a distinct mechanism of action relative to the bisphosphonate zoledronic acid, for prevention of SRE. This pre-planned analysis evaluates the efficacy and safety of denosumab versus zoledronic acid across three pivotal studies. Methods: Patient-level data from three identically designed, randomised, double-blind, active-controlled, phase 3 trials of patients with breast cancer, prostate cancer, other solid tumours or multiple myeloma were combined. End-points included time to first SRE, time to first and subsequent (multiple) SRE, adverse events, time to disease progression and overall survival. Findings: Denosumab was superior to zoledronic acid in delaying time to first on-study SRE by a median 8.21 months, reducing the risk of a first SRE by 17% (hazard ratio, 0.83 [95% confidence interval (CI): 0.76-0.90]; P < 0.001). Efficacy was demonstrated for first and multiple events and across patient subgroups (prior SRE status; age). Disease progression and overall survival were similar between the treatments. In contrast to zoledronic acid, denosumab did not require monitoring or dose modification/withholding based on renal status, and was not associated with acute-phase reactions. Hypocalcaemia was more common for denosumab. Osteonecrosis of the jaw occurred at a similar rate (P = 0.13). Conclusion: Denosumab was superior to zoledronic acid in preventing SRE with favourable safety and convenience in patients with bone metastases from advanced cancer