Amgen has detailed its results from a phase 3, head-to-head trial evaluating denosumab versus Zometa in the treatment of bone metastases. The trial was conducted in 2,046 patients with advanced breast cancer that met its primary and secondary endpoints and demonstrated superior efficacy compared to Zometa.
According to Amgen, denosumab administered subcutaneously demonstrated superiority for both delaying the time to the first on-study skeletal related events (SREs), and delaying the time to first-and-subsequent SREs. Both results were statistically significant in the 34 month study. The median time to first on-study SRE was 26.5 months for Zometa.
Overall, the incidence of adverse events (96% denosumab, 97% Zometa) and serious adverse events (44% denosumab, 46% Zometa) was consistent with what has previously been reported for these two agents.
Alison Stopeck, associate professor of medicine at Arizona Cancer Center for University of Arizona Health Sciences Center, said: “Denosumab was superior to Zometa in preventing skeletal related events and delayed worsening of bone pain. In addition, denosumab also presented some potential tolerability advantages for many patients, including a lower incidence of renal toxicity and acute phase reactions, combined with the convenience of a monthly subcutaneous injection. Denosumab would be a welcome new treatment option for advanced breast cancer patients.”
The phase 3 was a randomised double-blind study, comparing denosumab with Zometa, was conducted in the patients who received either 120mg of denosumab subcutaneously every four weeks or Zometa administered intravenously at a dose of 4mg in a 15 minute infusion every four weeks.