Denosumab in Postmenopausal Women with Low Bone Mineral Density

Background Receptor activator of nuclear factor-κB ligand (RANKL) is essential for osteoclast differentiation, activation, and survival. The fully human monoclonal antibody denosumab (formerly known as AMG 162) binds RANKL with high affinity and specificity and inhibits RANKL action. Methods The efficacy and safety of subcutaneously administered denosumab were evaluated over a period of 12 months in 412 postmenopausal women with low bone mineral density (T score of –1.8 to –4.0 at the lumbar spine or –1.8 to –3.5 at the proximal femur). Subjects were randomly assigned to receive denosumab either every three months (at a dose of 6, 14, or 30 mg) or every six months (at a dose of 14, 60, 100, or 210 mg), open-label oral alendronate once weekly (at a dose of 70 mg), or placebo. The primary end point was the percentage change from baseline in bone mineral density at the lumbar spine at 12 months. Changes in bone turnover were assessed by measurement of serum and urine telopeptides and bone-specific alkaline p...