A Randomized, Placebo-Controlled Study of Romosozumab for the Treatment of Hip Fractures

Background: Romosozumab is a bone-forming antibody that increases bone formation and decreases bone resorption. We conducted a double-blinded, randomized, phase-2, dose-finding trial to evaluate the effect of romosozumab on the clinical outcomes of open reduction and internal fixation of intertrochanteric or femoral neck hip fractures. Methods: Patients (55 to 94 years old) were randomized 2:3:3:3 to receive 3 subcutaneous injections of romosozumab (70, 140, or 210 mg) or a placebo postoperatively on day 1 and weeks 2, 6, and 12. The primary end point was the difference in the mean timed Up & Go (TUG) score over weeks 6 to 20 for romosozumab versus placebo. Additional end points included the time to radiographic evidence of healing and the score on the Radiographic Union Scale for Hip (RUSH). Results: A total of 332 patients were randomized: 243 to receive romosozumab (70 mg, n = 60; 140 mg, n = 93; and 210 mg, n = 90) and 89 to receive a placebo. Although TUG scores improved during the study, they did not differ significantly between the romosozumab and placebo groups over weeks 6 to 20 (p = 0.198). The median time to radiographic evidence of healing was 16.4 to 16.9 weeks across treatment groups. The RUSH scores improved over time across treatment groups but did not differ significantly between the romosozumab and placebo groups. The overall safety and tolerability profile of romosozumab was comparable with that of the placebo. Conclusions: Romosozumab did not improve the fracture-healing-related clinical and radiographic outcomes in the study population.