Romosozumab followed by denosumab in Japanese women with high fracture risk in the FRAME trial

Introduction This post-hoc analysis of the FRAME study investigated the long-term efficacy and safety of romosozumab followed by denosumab in postmenopausal Japanese women with osteoporosis at high fracture risk. Materials and methods Data from Japanese women with a high fracture risk participating in the international, randomised, double-blind, placebo-controlled, phase 3 FRAME study were analysed. High risk of fracture was defined as ≥ 1 fragility fracture with bone mineral density (BMD) ≤ − 2.5 standard deviations [SD], > 2 prevalent vertebral fractures, prevalent semiquantitative grade 3 vertebral fracture, or lumbar spine BMD < − 3.3 SD. Endpoints included incidence of new vertebral fracture at 12, 24 and 36 months and percentage change from baseline in BMD at the lumbar spine, total hip and femoral neck. Results 187 Japanese subjects at high risk of fracture were enrolled in FRAME. Incidence of new vertebral fractures was lower with romosozumab/denosumab vs. placebo/denosumab at 12, 24 and 36 months (relative risk reduction at all timepoints: 84%; p = 0.056). BMD increases at 12, 24 and 36 months were greater in subjects receiving romosozumab/denosumab than placebo/denosumab (lumbar spine: 16.3%, 21.5% and 23.2% vs 0.4%, 8.1% and 10.4%; total hip: 4.9%, 7.9% and 8.9% vs 0.4%, 2.8% and 4.1%; femoral neck: 4.8%, 7.6% and 8.1% vs 0.3%, 3.3% and 3.7%, respectively; all p < 0.001 vs placebo/denosumab). Adverse events were generally balanced between groups. Conclusion Romosozumab/denosumab in Japanese subjects at high risk of fracture resulted in significant BMD gains and numerically lower vertebral fracture rate vs. placebo/denosumab at all timepoints measured.