Which Bone Metastasis Drug Is Better?

Breast cancer metastasis drug denosumab superior in trial

(RxWiki News) When breast cancer spreads to the bones, various drugs are available to control the disease. This class of drugs is called biophosphonates. A manufacturer-funded study suggests its drug is better than others.

Women whose breast cancer has moved to the bones responded better to denosumab than to zoledronic acid.

Denosumab is sold under the brand names Xgeva and Prolia. Zoledronic acid is sold as Aclasta, Reclast, Zomera and Zometa.

"Talk to your oncologist about the latest drug therapies."

An international phase III trial involving some 2,000 patients was led by Miguel Martin, MD, PhD of Complutense University in Madrid, Spain.

“Our data indicate that denosumab should be the treatment of choice for the prevention of skeletal-related events and hypercalcemia in patients with breast cancer that has metastasized to the bone,” said Dr. Martin.

When cancer spreads (metastasizes) to the bone, patients can suffer from a condition where there's too much calcium in the blood (hypercalcemia), broken bones and compression of the spinal cord.

Biophosphonates can delay these - what scientists call skeletal-related events. The drugs have some serious side effects, though, including kidney problems and bone fractures.

For this study, 2,046 women with breast cancer received either denosumab and a placebo, or zoledronic acid and a placebo.

Of the women taking denosumab, 31 percent had these skeletal-related events, while 36 percent taking zoledronic acid had the problems.

Researchers found that women receiving denosumab had a 26 percent decreased need for radiation to the bone and had fewer disease complications than did those taking the other medication. 

The denosumab patients also had fewer side effects including flu-like symptoms and kidney problems than did the other women.

"The importance of the study by Martin et al. is that it shows decrease in skeletal related events using treatment with denosumab versus zolendronic acid," Patrick D. Maguire, MD a radiation oncologist in North Carolina, told dailyRx in an email.  He was not involved with this study.

"Differences in costs of the two therapies may impact changes in adoption of the newer therapy by oncologists for their patients," said Dr. Maguire, who is also author of When Cancer Hits Home: An Empowered Patient is the Best Weapon Against Cancer. 

Denosumab (Xgeva) costs about $1,800 per treatment. Zoledronic acid (Zometa) costs about $900 per treatment.

This study was published August 14 in Clinical Cancer Research, a journal of the American Association for Cancer Research.

Amgen, Inc., the maker of denosumab, funded the study. Many of the authors, including Dr. Martin, have served as advisors for Amgen and Novartis, which makes zoledronic acid. The authors disclosed financial relationships with other pharmaceutical companies, including GlaxoSmithKline, Sanofi-Aventis, Roche and others.

Review Date: 
August 14, 2012