Denosumab densitometric changes assessed by quantitative computed tomography at the spine and hip in postmenopausal women with osteoporosis

Abstract

FREEDOM was a phase 3 trial in 7808 women aged 60-90yr with postmenopausal osteoporosis. Subjects received placebo or 60 mg denosumab subcutaneously every 6mo for 3yr in addition to daily calcium and vitamin D. Denosumab significantly decreased bone turnover; increased dual-energy X-ray absorptiometry (DXA) areal bone mineral density (aBMD); and significantly reduced new vertebral, nonvertebral, and hip fractures. In a subset of women (N=209), lumbar spine, total hip, and femoral neck volumetric BMD (vBMD) were assessed by quantitative computed tomography at baseline and months 12, 24, and 36. Significant improvement from placebo and baseline was observed in aBMD and vBMD in the denosumab-treated subjects at all sites and time points measured. The vBMD difference from placebo reached 21.8%, 7.8%, and 5.9%, respectively, for the lumbar spine, total hip, and femoral neck at 36mo (all p≤0.0001). Compared with placebo and baseline, significant increases were also observed in bone mineral content (BMC) at the total hip (p<0.0001) largely related to significant BMC improvement in the cortical compartment (p<0.0001). These results supplement the data from DXA on the positive effect of denosumab on BMD in both the cortical and trabecular compartments.