Effectiveness of romosozumab in patients with osteoporosis at high fracture risk: a Japanese real-world study

Introduction To describe the real-world use of romosozumab in Japan, we conducted a chart review of > 1000 Japanese patients with osteoporosis (OP) at high risk of fracture, across multiple medical institutions. Materials and methods Treatment-naïve and prior OP-treatment patients who received romosozumab for 12 months followed by ≥ 6 months of sequential OP treatment were included. The primary objective described the baseline demographics and clinical characteristics; secondary objectives evaluated changes in bone mineral density (BMD) and bone turnover markers in all patients and effectiveness of romosozumab in a sub-group of treatment-naïve patients using the fracture risk assessment tool (FRAX ® ). Results Of the 1027 patients (92.4% female), 45.0% were treatment-naïve. The mean ± SD age of treatment-naïve versus prior OP-treatment patients was 76.8 ± 8.5 and 77.1 ± 8.5 years. The most frequent prior OP treatment was bisphosphonates (45.0%). Romosozumab treatment for 12 months increased BMD at the lumbar spine in all groups; the median percent change from baseline in lumbar spine BMD was higher in the treatment-naïve (13.4%) versus prior OP-treatment group (bisphosphonates [9.2%], teriparatide [11.3%], denosumab [DMAb, 4.5%]). DMAb, bisphosphonates, or teriparatide after romosozumab maintained the BMD gains at all skeletal sites at month 18 in treatment-naïve patients. Most treatment-naïve patients were at high risk of fracture, BMD increased consistently with romosozumab regardless of the baseline fracture risk assessed by FRAX. Conclusion This large-scale, multicenter chart review provides clinically relevant insights into the profiles of patients initiating romosozumab, effectiveness of real-world romosozumab use, and sequential therapy in Japanese patients at high risk of fracture.