Denosumab Superior to Zoledronic Acid for Delaying SREs in Bone Metastasis
“Denosumab was superior to zoledronic acid in preventing SRE with favorable safety and convenience in patients with bone metastases from advanced cancer,” reported Allan Lipton, MD, of the Milton S. Hershey Medical Center at Pennsylvania State University in Hershey, Pennsylvania, and his colleagues.
Disease progression and overall survival (OS) were not different between patients administered denosumab and those administered zoledronic acid.
The study analyzed patient data “from three identically designed, randomized, double-blind, active-controlled, phase 3 trials of patients with breast cancer, prostate cancer, other solid tumors or multiple myeloma were combined,” the authors reported. End-points were time to first SRE, time to multiple (second or subsequent) SRE, toxicities, time to disease progression and OS.
“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% (HR 0.83 [95% CI: 0.76-0.90]; P<0.001),” they reported. Denosumab was also associated with an 18% reduced risk of multiple SRE compared to zoledronic acid (Rate Ratio 0.82 [95% CI: 0.75-0.89];P<0.001).
Grade 3 or 4 hypocalcaemia rates were higher in patients administered denosumab (3.1%) than zoledronic acid (1.3%; a P-value for statistical significant was not reported). Serious adverse events occurred in 56.3% of denosumab-arm patients and 57.1% of zoledronic acid patients, resulting in study discontinuation rates of 9.5% and 9.9%, respectively. Rates of osteonecrosis of the jaw were similar between patients receiving denosumab and those receiving zoledronic acid (P=0.13).
“In contrast to zoledronic acid, denosumab did not require monitoring or dose modifications/withholding based on renal status, and was not associated with acute-phase reactions,” the authors noted.
Several of the coauthors have received Amgen funding. The authors disclosed that an Amgen-hired editorial consultant “assisted with manuscript drafting, editing and formatting.”