Romosozumab efficacy and safety in European patients enrolled in the FRAME trial

Summary In this post hoc analysis, we assessed romosozumab efficacy and safety in European patients enrolled in FRAME. Romosozumab treatment through 12 months, followed by denosumab for a further 24 months, resulted in early and sustained risk reduction for major fracture categories, associated with large gains in bone mineral density. Introduction In the multinational FRAME phase 3 trial of romosozumab in postmenopausal women with osteoporosis, marked differences between clinical and non-vertebral fracture outcomes were observed among patients from Central and Southern America versus rest of world. This post hoc analysis assessed romosozumab efficacy and safety in European patients enrolled in the FRAME trial and extension study. Methods In FRAME (NCT01575834), patients were randomised 1:1 to romosozumab 210 mg or placebo monthly (QM) for 12 months, followed by open-label denosumab 60 mg Q6M to month 36, including a 12-month extension study. We report incidence of major fracture outcomes, bone mineral density (BMD) change from baseline and safety for European patients enrolled in FRAME. Results In FRAME, 3013/7180 (41.96%) patients were European; 1494 received romosozumab and 1519 received placebo. Through 12 months, romosozumab reduced fracture risk versus placebo for non-vertebral fracture (1.4% versus 3.0%; p = 0.004), clinical fracture (1.4% versus 3.6%; p < 0.001), new vertebral fracture (0.4% versus 2.1%; p < 0.001) and major osteoporotic fracture (0.9% versus 2.8%; p < 0.001), with results sustained through 36 months following transition to denosumab. Hip fractures were numerically reduced with romosozumab at month 12 (0.2% versus 0.6%; p = 0.092). Romosozumab increased BMD versus placebo at month 12; all patients in the romosozumab and placebo groups experienced further increases by month 36 after transition to denosumab. Adverse events were balanced between groups. Conclusions Among European patients in FRAME, romosozumab resulted in early and sustained risk reduction for all major fracture categories, associated with large BMD gains that continued after transition to denosumab.