In a Phase III clinical trial among men receiving androgen-deprivation therapy for nonmetastatic prostate cancer, treatment with investigational drug denosumab improved bone density and reduced the risk of vertebral fractures.
Prostate cancer is the most commonly diagnosed cancer (other than skin cancer) among men in the United States. One common approach to treatment of prostate cancer is androgen deprivation therapy (ADT), also referred to as hormonal therapy. ADT interferes with the growth of prostate cancer by reducing circulating testosterone levels.
A significant side effect associated with ADT is loss of bone density or bone mass. Bone loss increases the risk of osteoporosis, bone fracture, pain, hospitalization, and immobility, and increases medical costs.
Denosumab is an investigational drug that targets a protein known as the RANK ligand. This protein regulates the activity of osteoclasts (cells that break down bone). Denosumab is being evaluated for the management of bone loss among patients with a variety of conditions, including cancer patients with treatment-related bone loss.
To evaluate the effect of denosumab among prostate cancer patients receiving ADT, researchers conducted a Phase III clinical trial among more than 1,400 men with nonmetastatic prostate cancer. In addition to ADT, men were assigned to receive either denosumab or a placebo.
- Compared with men treated with placebo, men treated with denosumab experienced significantly greater increases in bone mineral density at the lumbar spine and other skeletal sites.
- Men treated with denosumab experienced significantly fewer vertebral fractures than men treated with placebo.
- The rate of adverse events was generally similar between men treated with placebo and men treated with denosumab.
These results suggest that denosumab may provide a new approach to improving bone density and reducing fracture risk among prostate cancer patients treated with ADT.
Patients who are receiving ADT may wish to speak with their physician regarding the risks and benefits of participating in a clinical trial further evaluating this or other novel therapeutic approaches. Sources of information regarding ongoing clinical trials include the National Cancer Institute (www.cancer.gov) and www.eCancerTrials.com.
Reference: Amgen Press Release. Amgen announces positive top-line results for denosumab treatment of bone loss in men with non-metastatic prostate cancer undergoing androgen deprivation therapy. Available at http://www.amgen.com/media/media_pr_detail.jsp?releaseID=1174433. Accessed July 14, 2008.