Is denosumab better than alendronate in the treatment of osteoporosis?

Denosumab is a fully human monoclonal antibody to receptor activator of nuclear factor kappaB ligand (RANKL), the principal mediator of osteoclastic bone resorption. By binding to RANKL, denosumab reduces the differentiation, activity and survival of osteoclasts, and thereby slows the rate of bone resorption. These antiresorptive effects led to the development of this agent as a treatment for osteoporosis. In studies conducted so far, denosumab is an efficacious and well-tolerated treatment for postmenopausal osteoporosis. Oral bisphosphonates are currently favored as first-line therapy for most patients with this condition and, therefore, studies that directly compare the effects of these agents with denosumab are of clinical interest. Here, I discuss a study by Brown et al. that compares the effects of denosumab and alendronate in women who have not previously received antiosteoporosis therapy, and place the findings in the context of other clinically relevant studies of this RANKL inhibitor.