Assessing cortical bone changes with Romosozumab after one year: Insights from an exploratory HR-pQCT study

Area of Science:

• Bone Biology and Metabolism
• Osteoporosis Treatment and Management
• Biomaterials Science

Background:

• Osteoporosis is a significant public health concern, increasing fracture risk in postmenopausal women.
• Romosozumab is an anabolic agent targeting bone formation, but its effects on bone microarchitecture and predictors of response require further elucidation.
• Understanding treatment response heterogeneity is crucial for optimizing osteoporosis management.

Purpose of the Study:

• To characterize bone microarchitecture changes following 6 and 12 months of romosozumab therapy.
• To identify responders based on cortical thickness increases at the distal radius (≥3% at 12 months).
• To explore factors associated with romosozumab treatment response in postmenopausal women with osteoporosis.

Main Methods:

• Prospective cohort study involving postmenopausal women with osteoporosis at very high fracture risk.
• High-resolution peripheral quantitative computed tomography (HR-pQCT), bone mineral density (BMD), and bone turnover markers assessed at baseline, 6, and 12 months.
• Patients classified as responders or non-responders based on 12-month changes in distal radius cortical thickness.

Main Results:

• Responders (56%) exhibited significant gains in cortical thickness and area at both distal tibia and radius by 12 months, with trends evident by 6 months.
• Non-responders showed no improvement or a decline in cortical parameters.
• Significant increases in lumbar spine and hip BMD were observed only in responders; PTH levels rose differently between groups.

Conclusions:

• Stratification by cortical thickness changes identified responders with rapid improvements in cortical bone, detectable as early as 6 months.
• Romosozumab demonstrates heterogeneous effects on bone microarchitecture, with a subset of patients showing substantial benefits.
• Further research is warranted to identify clinical predictors of romosozumab responsiveness and explore shorter treatment durations for selected patients.