In a double-blind study, the monoclonal antibody denosumab was both non-inferior and superior to the bisphosphonate risedronate for the treatment of glucocorticoid-induced osteoporosis (GIOP). Patients were randomly assigned to receive 60 mg denosumab subcutaneously every 6 months (n = 398) or 5 mg oral risedronate daily (n = 397); both groups also received placebo. At 12 months, denosumab had greater effects than risedronate on bone mineral density at the lumbar spine both in patients who were already using glucocorticoids (4.4% versus 2.3%; P < 0.0001) and in those initiating glucocorticoid therapy (3.8% versus 0.8%; P < 0.0001).