FDA approves treatment for back pain, complications of osteoporosis from cancer therapy

Sep 20 2011
The Food and Drug Administration (FDA) approved the drug denosumab, currently used to treat back pain and other complications of osteoporosis, as a remedy for bone loss due to hormonal deficiencies stemming from cancer therapy.

More than 40 million Americans either have osteoporosis or are at high risk, according to the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), a division of the National Institutes of Health (NIH). Osteoporosis is a condition in which the bones begin to deteriorate and lose density. Increasingly fragile bones are more prone to breaking, and the vertebrae that protect the spinal cord are some of the most vulnerable spots for fractures resulting from the disease. Broken vertebrae can lead to back pain.

Currently, the drug denosumab, given as an injection, may be prescribed to slow bone loss and strengthen the bones in order to treat osteoporosis. Doctors may also prescribe it to prevent fractures in cases of cancer that spread to the bones, according to the NIH. Vitamin D supplements may also be taken in conjunction with the drug.

In addition to a diet rich in vitamin D and calcium, people can avoid osteoporosis with the help of exercises to strengthen the bones, including walking, dancing and weight training, according to NIAMS.

The FDA has recently approved denosumab to treat bone loss that may result from certain therapies to treat cancers of the breast or prostate. These treatments, collectively known as hormone ablation therapy, block the effects of sex hormones that may spur the growth of these cancers. The FDA's new approval of denosumab makes it the first treatment cleared by the agency for the treatment of bone loss due to hormone ablation therapy for cancer.

Aromatase inhibitors prevent parts of the female body, excluding the ovaries, from producing estrogen, a hormone that can affect the growth of some types of breast cancer, according to the National Cancer Institute. Similarly, doctors may prescribe medications to prostate cancer patients that block the effects of androgens. However, both of these therapies can weaken the bones of their respective patients.

Approval of denosumab is based on two clinical Phase III trials. Men taking denosumab while undergoing hormone ablation for non-metastatic prostate cancer had higher measurements of bone mineral density (BMD) in their lumbar spine compared to men taking placebos. After three years, those on denosumab also cut their risk for vertebral fractures by 62 percent.

Similarly, after two years, women taking denosumab in addition to aromatase inhibitors for breast cancer had higher BMD scores compared to controls.