Effects of romosozumab and teriparatide on hip bone using 3D-SHAPER in postmenopausal women with osteoporosis

DXA-based 3D-modeling (3D-DXA) of the hip was used to assess estimated changes in bone integral, cortical, and trabecular parameters and analyze 3D anatomical distribution of changes in bone parameters over time in women who transitioned to romosozumab or teriparatide following treatment with oral bisphosphonates in STRUCTURE and in treatment-naïve women in a romosozumab phase 2 dose-ranging study (Phase 2 study). Data from women who had hip DXA scans at baseline and months 6 and 12 in STRUCTURE or baseline and months 3, 6, and 12 in the Phase 2 study and provided consent for future research were analyzed. 3D-SHAPER software was applied to generate patient-specific 3D-models from hip DXA scans. Percentage changes from baseline in areal BMD (aBMD), integral volumetric BMD (vBMD), cortical thickness, cortical vBMD, cortical surface BMD (sBMD), and trabecular vBMD were evaluated. Data of 308 women from STRUCTURE (romosozumab, 160; teriparatide, 148) with 3D-DXA assessments at baseline and months 6 and 12 were analyzed. Greater increases in aBMD, integral vBMD, cortical thickness, cortical vBMD, cortical sBMD, and trabecular vBMD were seen by month 6 following treatment with romosozumab vs teriparatide (p < .001); additional gains were observed through month 12 (p < .001). Conversely, teriparatide treatment led to loss in cortical thickness, cortical vBMD, and cortical sBMD. Data of 70 women (romosozumab, 22; teriparatide, 23; placebo 25) from the Phase 2 study with 3D-DXA assessments at baseline and months 3, 6, and 12 were analyzed. Greater increases in cortical thickness, cortical vBMD, cortical sBMD, and trabecular vBMD were observed with romosozumab vs teriparatide or placebo. In summary, results from 3D-DXA analysis of DXA images from STRUCTURE and the Phase 2 study support established evidence that romosozumab improves hip cortical bone density and structure in treatment-naïve patients or patients previously treated with bisphosphonates, thereby contributing to the rapid antifracture efficacy of romosozumab.