THOUSAND OAKS, California—Denosumab significantly delayed the time to the first skeletal-related event in breast cancer patients and significantly reduced first and subsequent skeletal related events compared to Novartis Oncology's Zometa^® (zoledronic acid), Amgen announced.

The company reported that a pivotal, Phase 3, head-to-head trial evaluating denosumab versus Zometa (zoledronic acid) in the treatment of bone metastases in 2,049 patients with advanced breast cancer showed that denosumab was better at delaying the time to the first on-study Skeletal Related Events (SREs: fracture, radiation to bone, surgery to bone, or spinal cord compression). Denosumab was also more effective at delaying the time to the first-and-subsequent SREs. 

Adverse events were similar between the two treatments, and osteonecrosis of the jaw (ONJ) was rare with either treatment.

Patients enrolled in the study were randomized in a one-to-one ratio to receive either 120 mg of denosumab subcutaneously every four weeks (Q4W) or Zometa administered intravenously at a dose of 4 mg single, 15 minute infusion every four weeks as per the labeled use.

"We are extremely pleased with the outcome of this important study, which shows that denosumab can reduce or delay the serious complications of bone metastases in breast cancer patients better than the current standard of care, and with a favorable benefit/risk profile," said Roger M. Perlmutter, MD, PhD, executive vice president of Research and Development at Amgen. "These results underscore the importance of the RANK Ligand pathway in bone disease, and offer the promise of improved care for patients with advanced breast cancer. We look forward to reviewing the results from a second Phase 3 study of denosumab effects in advanced cancer patients later this year."