Denosumab is effective toward glucocorticoid-induced osteoporosis patients complicated with rheumatic diseases regardless of prior anti-osteoporotic drugs.

We examined the efficacy and safety of denosumab as treatment for glucocorticoid-induced osteoporosis (GIOP) patients complicated with rheumatic diseases, by measuring patients' lumber bone mineral density (BMD) and bone turnover markers. A total of 66 consecutive patients for whom denosumab was initiated between July 2013 and August 2016 were enrolled and evaluated for 12 months. All of the patients were treated with glucocorticoids for underlying rheumatic diseases. The clinical assessment included measurements of the BMD of the lumbar spine (L2-L4) by a dual-energy X-ray absorptiometry technique and the bone turnover markers N-terminal telopeptide of type 1 collagen (NTX) in urine, serum intact procollagen type 1 N-terminal propeptide (P1NP), and bone-specific alkaline phosphatase (BAP) at baseline, 6 months and 12 months after the start of denosumab treatment. Adverse events (AEs) until 12 months were also analyzed. The mean percentage changes in BMD from baseline to 6 and 12 months were significant (2.85% increase, p < 0.0001 and 4.40% increase, p < 0.0001, respectively) regardless of the prior anti-osteoporotic drugs treatment (16 no transition from anti-osteoporotic drugs, 27 transition from bisphosphonate, 23 transition from teriparatide). The decreases in NTX, P1NP and BAP at 6 and 12 months were also significant. No serious AEs were noted. A multivariable logistic analysis showed that the prednisolone dose at baseline was associated with the clinical response to denosumab. In a real-world setting, denosumab was effective and safe for treating GIOP patients complicated with rheumatic diseases regardless of prior anti-osteoporotic drug treatment.