A new clinical research has sown that Amgen's new osteoporosis drug denosumab delayed bone problems in patients with advanced breast cancer five months more than Novartis's Zometa.

The long term trial data showed that Amgen drug proved better by 18 percent at delaying first bone problem and 22 percent better in time to first and subsequent event in women whose breast cancer has spread to the bone.

Amgen has received US approval for Denosumab ot be sold under brand name Xgeva for reducing the risk of bone for patients whose cancers had spread to the bone and it is sold under the name Prolia as a treatment for osteoporosis.

Roy Baynes, Amgen's vice president of global development and therapeutic head of hematology and oncology said, "The findings confirm what we saw in the primary analysis. Xgeva continues to be superior in terms of efficacy. "They reinforce the efficacy; they reinforce the superiority and they continue to show a very similar safety profile" to Zometa.

The study included 2,046-patient, who received a 120-milligram injection of denosumab or a 4 mg intravenous infusion of Zometa every four weeks. The comoany said that once it was found that Amgen drug was superior, the trial were switched over to Xgeva.

The rate of side effects was 96.2 percent for denosumab patients and 97.4 percent for those on Zometa. Denosumab, or Xgeva also does not have flu-like symptoms sometimes associated with Novartis drug.