Comparison of efficacy of romosozumab with denosumab and risedronate in patients newly initiating glucocorticoid therapy

Context: Wnt/β-catenin signaling pathway is one of the pathogenic mechanisms of glucocorticoid-induced osteoporosis (GIOP). We previously reported the potential of inhibiting sclerostin as a treatment for GIOP.

Objective: To compare the efficacy of romosozumab (ROMO), a monoclonal antibody against sclerostin, with existing therapy for GIOP.

Methods: Patients with rheumatic diseases who had not previously received treatment for osteoporosis and were newly treated with prednisolone 15 mg/day or more were randomly assigned to receive ROMO, denosumab (DMAb), or bisphosphonates (BP). After the initiation of GC therapy, we measured the bone mineral density (BMD) of the lumbar spine, femoral neck, and total hip every 6 months and bone turnover markers every 3 months for 12 months.

Results: Eleven patients were assigned to the ROMO group, 14 to the DMAb group, and 14 to the BP group. The median [25th to 75th percentile] percent change in lumbar spine BMD from baseline at 12 months was the greatest in the ROMO group (ROMO; 8.6 [3.1-12.4] %, DMAb; 3.3 [1.5-6.2] %, BP; -0.4 [-3.4-1.1] %). Among bone formation markers, serum levels of bone alkaline phosphatase were slightly elevated in the ROMO group, while those of N-terminal propeptide of type I procollagen and osteocalcin decreased in all three groups; however, these changes were smaller in the ROMO group. Serum levels of bone resorption markers and a urine bone quality marker decreased in all groups.

Conclusion: Treatment with ROMO significantly increased lumbar spine BMD in GC-treated patients, suggesting that ROMO is effective for GIOP.