Study Shows Experimental Amgen Bone-Loss Drug Aids Prostate Cancer Patients

By Aaron Poehler

Published on July 16, 2008

Thousand Oaks, California-based Amgen Inc. announced Monday that its experimental drug denosumab reduced risks of osteoporosis and vertebral fractures in a study of men being treated with prostate cancer medicines that can cause bone loss.

The Phase III trial study, which included 1,400 men with non-metastatic prostate cancer undergoing androgen deprivation therapy, was conducted over a three-year period and was said by Amgen to show that patients receiving denosumab demonstrated greater increase in bone mineral density and less than half the number of new vertebral fractures than patients who received a placebo.

A previous denosumab study showed that the drug successfully increased bone mineral density in women with breast cancer receiving aromatase inhibitor therapy. A Phase III trial of denosumab in women with post-menopausal osteoporosis is expected later this year.

Denosumab is a bioengineered antibody, administered twice yearly via injection, that targets proteins involved with cells called osteoclasts which erode bone material. The experimental drug is said to be seen as key to the future of Amgen, which has struggled in the wake of safety concerns over the company's anemia drugs Aranesp and Epogen which led many doctors to cease prescribing the medications; previously, sales of Aranesp and Epogen had accounted for nearly half of Amgen's revenue in 2006.