Abstract
The impact of romosozumab on the bone mineral density surrogate threshold effect (BMD-STE) in postmenopausal women with severe osteoporosis is unknown. Significant BMD gains with romosozumab were observed and 60% of patients achieved the BMD-STE at month 12, regardless of bisphosphonate pre-exposure. Romosozumab offers effective treatment in high-risk fracture patients. PURPOSE: A real-life study to investigate the impact of romosozumab on the bone mineral density surrogate threshold effect (BMD-STE) for minimal fracture risk reduction. METHODS: A retrospective analysis of postmenopausal women with severe osteoporosis newly treated with romosozumab from 29 November 2022 until 01 July 2024 (extraction date). BMD of the lumbar spine (L1-L4), femoral neck, and total hip was assessed at baseline and months 6 and 12, and the BMD-STE was evaluated. Blood serum samples were assayed for bone turnover markers and calcium-phosphate metabolism. Subgroup analyses compared patients minimally exposed to bisphosphonates with patients pre-exposed to bisphosphonates. Patients contributed to the analysis according to their observation period. RESULTS: Overall, 133 postmenopausal women with severe osteoporosis newly treated with romosozumab were included (mean age 72.5 ± 9.5 years, lowest T score -3.3 ± 0.87); 70 patients were followed up to month 6, and 41 patients up to month 12. Significant increases in BMD were observed at all sites (all p < 0.05 vs. baseline). At month 6, 56.4% of patients reached the STE for minimal fracture risk reduction for all fractures. Among patients with a lumbar spine T-score ≤ -2.5 at baseline, 18.2% and 32.0% reached the T-score target (> -2.5) at months 6 and 12, respectively. P1nP levels increased significantly and CTX levels decreased significantly at months 3 and 6, (all p < 0.05 vs. baseline). CONCLUSION: The rapid increase in BMD with romosozumab supports its use for reducing fracture risk in postmenopausal women with severe osteoporosis, regardless of prior bisphosphonate exposure.