Long-term effectiveness and safety of denosumab for osteoporosis in patients with rheumatic diseases.

Objective: The long-term effectiveness of denosumab, an anti-RANKL monoclonal antibody, for increasing bone mineral density (BMD) and reducing fracture risk in postmenopausal women with osteoporosis has been demonstrated. However, its long-term effectiveness and safety in patients with rheumatic diseases remain unclear. Therefore, the present study investigated the long-term effectiveness and safety of denosumab for osteoporosis in patients with rheumatic diseases.

Methods: This retrospective study included patients who received denosumab between August 2013 and August 2022. We evaluated BMD at the lumbar spine for up to 7 years and at the femur for up to 3 years. The effects of glucocorticoid (GC) usage, age, and renal function on BMD in patients receiving denosumab were assessed. The retention rate and adverse events were also evaluated.

Results: One hundred and sixty-five patients with rheumatic diseases were enrolled (median age 66.5 years, 92.1% female, and 68.5% on GC therapy). Lumbar spine BMD significantly increased over 7 years (p < 0.001), while femoral neck, trochanter, and total hip BMD significantly increased for up to 3 years (p < 0.001). Lumbar spine BMD significantly increased regardless of the GC dose, age, or renal dysfunction. The retention rate of denosumab at 7 years was 68.1%. The most common serious adverse event was infection. Two cases of osteonecrosis of the jaw and 10 new fractures were observed during treatment with denosumab.

Conclusion: The present study suggests that the long-term use of denosumab is an effective and generally safe option for increasing BMD in patients with rheumatic diseases.