Efficacy and safety of romosozumab in postmenopausal women with osteoporosis who used antiresorptive osteoporosis drugs: a prospective observational study

Abstract

Abstract Background: Globally there has been an increase in the number of patients receiving long-term antiresorptive drugs for the treatment of postmenopausal osteoporosis; however, there is little evidence to guide decisions regarding when and how to stop or switch antiresorptive drugs. In this prospective observational study, we investigated the efficacy of romosozumab in women treated with conventional antiresorptive osteoporosis drugs for more than 3 years. Methods: Despite more than 36 months of treatment with conventional antiresorptive drugs for postmenopausal osteoporosis, postmenopausal women with lumbar and femoral neck bone mineral density (BMD) of less than -2.5 SD by the DXA method were recruited. Patients who provided written informed consent were treated with romosozumab for 12 months, and its efficacy and safety were closely monitored by periodically measuring the lumbar and femoral neck BMD as well as the bone turnover markers, including serum P1NP and I-CTP. Results: A total of 21 patients were enrolled in this study. The median age was 73 years, and the median observation period was 833 (range: 378–1141) days. The median BMD before romosozumab treatment was 0.771 g/cm2 at the lumbar spine (T score: -2.0) and 0.488 g/cm2 at the femoral neck (T score: -2.8). After 12 months of treatment, the percent change in BMD was significantly increased to 6.18% in the lumbar spine (P < 0.001); however, it remained unchanged in the femoral neck (P = 0.46). The P1NP values increased significantly from baseline to 455.8% (P < 0.001) and I-CTP values increased significantly to 30.3% (P < 0.001). One patient presented with periodontitis and a vertebral fracture during treatment. Multiple regression analysis revealed that the factors affecting changes in the lumbar BMD at 12 months were the baseline BMD (partial regression coefficient = -1.39, P < 0.001) and P1NP values (partial regression coefficient = 0.00015, P < 0.05). Conclusions: Romosozumab treatment significantly increased the lumbar BMD and bone turnover markers in patients previously treated with conventional antiresorptive osteoporosis drugs, and switching the therapy to romosozumab can be considered a treatment option. Trial registration: This study was registered in the Japan Registry of Clinical Trials (No. jRCT1051210070) on 23 July, 2019.