Evaluation of romosozumab's effects on bone marrow adiposity in postmenopausal osteoporotic women: results from the FRAME bone biopsy sub-study.

Romosozumab, a humanized monoclonal antibody that binds and inhibits sclerostin, produces a marked increase in bone formation with a concomitant decreased bone resorption. This transient rise in bone formation in the first 2 months of treatment is mainly due to an increased modeling-based bone formation. This requires the recruitment and differentiation of osteoblasts, one possibility being a preferential switch in commitment of precursors to osteoblasts over adipocytes.

Reconstruction of remodeling units reveals positive effects after 2 and 12 months of romosozumab treatment.

Romosozumab treatment results in a transient early increase in bone formation and sustained decrease in bone resorption. Histomorphometric analyses revealed that the primary bone-forming effect of romosozumab is a transient early stimulation of modeling-based bone formation on cancellous and endocortical surfaces. Furthermore, preclinical studies have demonstrated that romosozumab may affect changes in the remodeling unit, resulting in positive bone balance.

Pre-treatment bone turnover does not influence the level of the response to alendronate in postmenopausal osteoporosis at the bone tissue level.

Purpose: The main effect of anti-resorptive agents such as bisphosphonates is a reduction of bone resorption, with a consequent marked decrease of bone turnover. This post-hoc analysis investigated the changes of histomorphometric parameters of bone turnover after alendronate (ALN), according to the baseline turnover.

Methods: Ninety postmenopausal women underwent a transiliac bone biopsy before and after 6 (n = 44) or 12 (n = 46) months of treatment with ALN (70 mg/week).

Interest of Bone Histomorphometry in Bone Pathophysiology Investigation: Foundation, Present, and Future.

Despite the development of non-invasive methods, bone histomorphometry remains the only method to analyze bone at the tissue and cell levels. Quantitative analysis of transiliac bone sections requires strict methodologic conditions but since its foundation more 60 years ago, this methodology has progressed. Our purpose was to review the evolution of bone histomorphometry over the years and its contribution to the knowledge of bone tissue metabolism under normal and pathological conditions and the understanding of the action mechanisms of therapeutic drugs in humans.