The Clinical Use of Denosumab for the Management of Low Bone Mineral Density in Postmenopausal Women

Osteoporosis is a leading cause of debility and declining quality of life in postmenopausal women worldwide. Treatment of osteoporosis has been ubiquitous throughout the developed world since the mid-1990s, most notably with the introduction of bisphosphonates in 1995. Nonetheless, the incidence of hip fractures increased by 25% between 1990 and 2000, despite advances in osteoporosis therapy. Studies indicate that bone density increases over the first 3 years of bisphosphonate therapy and then plateaus or perhaps even declines, placing these patients at greater risk of fracture. Since hip fractures are associated with increased morbidity, mortality, and increased cost of health care, improvements in treating osteoporosis are critical. Denosumab is a novel monoclonal antibody targeted against the receptor activator of nuclear factor-κB ligand (RANKL) that inhibits osteoclast activity. Initial data suggest that denosumab increases bone mineral density for greater than 3 years. Of greater importance, denosumab has been shown to decrease vertebral fractures by 68%, nonvertebral fractures by 19%, and hip fractures by 42% for at least 36 months. Data also indicate that the safety profile of denosumab is equivalent to other drugs used in osteoporosis management, but potential risks of immunosuppression and cancer have been hypothesized.