Treatment of osteoporosis with denosumab.

Osteoporosis is a common skeletal disease associated with an imbalance in bone remodeling resulting in a reduction in bone strength and increased fracture risk. The principal regulator of osteoclastic bone resorption is receptor activator of nuclear factor-kappaB ligand (RANKL), a cytokine member of the tumor necrosis factor family. The binding of RANKL to its receptor on the cell surface of osteoclasts and pre-osteoclasts increases the formation, activity, and survival of osteoclasts. Denosumab is an investigational fully human monoclonal antibody to RANKL. By binding to RANKL, denosumab prevents RANKL from binding to its receptor, resulting in a decrease in bone resorption due to reduction in the formation, activity, and survival of osteoclasts. In postmenopausal women with osteoporosis, denosumab 60 mg by subcutaneous injection every 6 months increased bone mineral density (BMD), reduced bone turnover markers, and reduced the risk of vertebral, hip, and non-vertebral fractures. In postmenopausal women with low BMD, denosumab increased BMD and reduced bone turnover markers. It was well tolerated with a safety profile generally similar to placebo. Denosumab is a promising emerging drug for the prevention and treatment of postmenopausal osteoporosis. It may be particularly useful in clinical practice for the treatment of patients with gastrointestinal contraindications or side effects with oral bisphosphonates and for patients with malabsorption.