Prostate cancer has been reported to have a high bone metastatic rate and longer survival duration by current
therapies, accordingly, the treatment for bone
metastasis is important to maintain a good quality of life. The standard medication for advanced
prostate cancer,
androgen deprivation
therapy(ADT)has been associated with bone loss, consequently, the management of controlling the risk of fracture is required. A new
drug denosumab is a fully human
monoclonal antibody that binds to RANKL, a
cytokine essential for the differentiation, function, and survival of osteoclasts which mainly regulate bone metabolic turnover. In a phase 3 clinical study in patients with bone
metastasis of castrate-resistant
prostate cancer, 120 mg denosumabsub cutaneously every 4 weeks statistically significantly delayed the time to first skeletal-related events(SRE)by 18% and also the time to first and subsequent on-study SRE by 18%when compared with that of the standard of care, 4 mg
zoledronic acid by iv infusion every 4 weeks. In another phase 3 clinical study in patients with castrate-resistant
prostate cancer without bone
metastases, 120 mg once in 4-week
subcutaneous injection of
denosumab has been indicated to delay the onset of the bone
metastasis significantly when compared with placebo. In another phase 3 clinical study in patients with
hormone-sensitive nonmetastatic
prostate cancer, 60 mg
denosumab subcutaneously every 6 months significantly reversed bone loss due to ADT and demonstrated statistically significant prevention of vertebral fractures compared with placebo. Based on these evidences, it has been proved that
denosumab is effective in many different stages across the disease continuum of advanced
prostate cancer. In US,
denosumab has been approved for the indication of prevention of SRE caused by bone
metastasis of solid
tumor since 2010.
Denosumab is useful for treatment of bone
metastases from
prostate cancer, because the administration route is an every 4-week
subcutaneous injection and, dose adjustment by renal impairment is not required. The use of
denosumab will be expected to largely contribute to
prostate cancer treatment in the future.