Bone Drug Reduces Fractures In Men Having Hormone Therapy For Prostate Cancer

Featured Article
Main Category: Prostate / Prostate Cancer
Also Included In: Bones / Orthopaedics
Article Date: 15 Jul 2008 - 3:00 PST

email to a friend   printer friendly   view / write opinions

Drugmaker Amgen Inc announced yesterday, Monday, that a large trial of its bone drug denosumab increased bone density and cut fractures in men with non-metastatic prostate cancer who were having hormone blocking therapy. A side effect of androgen deprivation therapy (ADT), which stops the male hormones feeding the cancer, is weaker bones and increased risk of fracture.

According to the National Cancer Institute, about half of prostate cancer patients undergo hormone therapy at some stage.

Amgen's three year pivotal phase 3 placebo controlled trial involved more than 1,400 men and showed that treatment with denosumab resulted in statistically significant rises in bone mineral density (BMD) at the lumbar spine (the main measure of the trial) and non-vertebral sites compared with placebo at various stages of the trial.

According to the company, the results were comparable with other studies on bone mineral density in women undergoing hormone therapy (aromatase inhibitor) for breast cancer and in post menopausal women with low bone mass.

During the prostate cancer trial, the group on denosumab had less than half the number of new vertebral fractures compared to the group on placebo, which the company said was a statistically significant result. Also, the denosumab group had fewer non-vertebral fractures during the 3 year trial.

The frequency and types of adverse events were broadly similar in the drug and placebo groups, with the most common adverse event being: arthralgia, back pain, constipation, and pain in extremity. About 5 per cent of the participants on placebo and 6 per cent of the drug group experienced serious adverse infectious events.

According to the Wall Street Journal, observers are watching this drug for further news of the adverse infectious side effects because the drug works by targetting the immune system.

Executive vice president of Research and Development at Amgen, Dr Roger Perlmutter, said in a company statement that:

"This pivotal study in men with prostate cancer demonstrated once again that denosumab increases BMD consistently at all sites measured."

"We are also excited by the reduction in vertebral fractures, which permits the conclusion that the increased BMD seen in patients receiving denosumab is associated with improved bone strength," he added.

Denosumab works by targetting the RANK ligand, a signalling molecule that bonds to osteoclasts (the cells that break down bone). It is the first fully human monoclonal antibody in late stage clinical development to do this, said Amgen in a statement.

According to the American Cancer Society, more tha 186,000 American men will be diagnosed with prostate cancer this year, and the disease will kill nearly 29,000.

The Wall Street Journal reported that analysts have welcomed the trial but that the results "don't ensure similar success in a study of the drug in women with osteoporosis".

Overall, Amgen is testing denosumab, or d-mab, in a total of over 19,000 patients with a variety of conditions.

Sources: Amgen press statement, Wall Street Journal.

Written by: Catharine Paddock, PhD
Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today