Chavassieux P, Chapurlat R, Portero-Muzy N, et al. - In this investigation, researchers assessed the impact of romosozumab on bone tissue. In a subset of 107 postmenopausal women with osteoporosis in the Fracture Study in Postmenopausal Women with Osteoporosis (FRAME), transiliac bone biopsies were conducted either after 2 (n = 34) or 12 ( n = 73) months of 210-mg once monthly romosozumab or placebo therapy to assess histomorphometry and microcomputed tomography-based microarchitectural endpoints. Compared with either baseline values assessed after a quadruple fluorochrome labeling or placebo after 2 months, significant increases in dynamic parameters of formation were linked to a significant reduction vs placebo in cancellous and endocortical bone resorption parameters. The authors concluded that romosozumab resulted in an early and transient increase in bone formation, but a persistent reduction in bone resorption. Eventually, antiresorptive action led to lower bone turnover. This impact led to important rises in bone mass and microarchitecture improvement.