Background: Romosozumab, a monoclonal antibody that binds sclerostin, increases bone formation and decreases bone resorption. Romosozumab has an excellent therapeutic effect on patients with osteoporosis. However, there are few reports investigated the efficacy and the effect of various factors relative to osteoporosis in real-world.

Objectives: We evaluated bone mineral density (BMD) and bone metabolism marker (BMM) change in osteoporosis patients treated with romosozumab, and assessed the effect of various factors, such as preosteoporosis treatment, history of fragility fracture and combination of vitamin D.

Methods: This study included 141 osteoporosis patients (132 female, mean age: 78.8 ± 7.5 years, mean hight: 151.1 ± 7.5 cm, mean weight: 50.9 ± 8.9 kg) treated with romosozumab. BMD measurements using dual energy X-ray absorptiometry (DXA) and BMM measurements using N-terminal propeptide of type 1 collagen (P1NP) were evaluated at 0, 4, 6, and 12 months after treatment. DXA were performed at the lumbar spine (n=92), at proximal femoral and femoral neck (n=92), and at distal third radius (n=49). We evaluated the influence of preosteoporosis treatment, history of fragility fracture and combination of vitamin D for BMD change.

Results: BMD at lumbar spine (5.2%: p<0.01, 9.2%: p<0.01, 10.8%: p<0.01), proximal femoral (1.3%: p=0.02, 2.8%: p<0.01, 4.5%: p<0.01) and femoral neck (2.0%: p=0.03, 2.7%: p=0.06, 5.0%: p=0.01) were significantly increased at 4, 8, 12 months after treatment. BMD at distal third radius (-1.5%: p<0.01, -0.8%: p=0.17, -1.0%: p=0.13) were not increased at 4, 8, 12 months after treatment. P1NP chane were 63% (p<0.01), 6.4% (p=0.55), -2.3% (p=0.2) at 4, 8, 12 months after treatment. There were no significant differences in 1 year improvement ratio of BMD at lumbar spine, proximal femoral and femoral neck between 38 patients with pretreatment of osteoporosis and 54 patients without pretreatment of osteoporpsis (13.5 vs 9.5%: p=0.1, 4.9 vs 4.4%: p=0.7, 6.1 vs 4.6%: p=0.67), between 33 patients with a history of fragility fracture and 59 patients without a history of fragility fracture (7.3 vs 11.7%: p=0.42, 0.8 vs 5.5%: p=0.08, -0.7 vs 6.6%: p=0.14), between 50 patients with romosozumab alone and 42 patients with romosozumab plus vitamin D (11.3 vs 10.0%: p=0.93, 4.1 vs 5.3%: p=0.59, 6.8 vs 2.3%: p=0.47). There were no significant differences in 1 year improvement ratio of BMD at distal third radius between 33 patients with pretreatment of osteoporosis and 16 patients without pretreatment of osteoporpsis (-1.1 vs -0.9%: p=0.63), between 31 patients with a history of fragility fracture and 18 patients without a history of fragility fracture (-1.5 vs -0.5%: p=0.3).

Conclusion: Romosozumab improved BMD at lumbar and femoral independently regardless of preosteoporosis treatment, history of fragility fracture and combination of vitamin D.

REFERENCES:

[1]Felicia Cosman et al. Romosozumab Treatment in Postmenopausal Women with Osteoporosis. N Engl J Med 2016; 375:1532-1543, DOI: 10.1056/NEJMoa1607948

Disclosure of Interests: None declared