Safety and effectiveness of denosumab in Japanese patients with rheumatoid arthritis: A 2-year post-marketing surveillance study

Objectives To investigate the 2 year safety and effectiveness of denosumab 60 mg in patients with rheumatoid arthritis (RA) in clinical practice in Japan.Methods This 2 year, prospective, observational cohort study included patients who initiated treatment with denosumab 60 mg for the progression of bone erosion associated with RA. Key endpoints were adverse drug reactions (ADRs), progression of bone erosion, and 28-joint Disease Activity Score based on C-reactive protein or erythrocyte sedimentation rate. Univariate and multivariate analyses were conducted to determine the risk factors for ADRs and the progression of bone erosion.Results In the safety analysis set (n = 1239), the incidence of ADRs was 3.0%; the most common ADRs were hypocalcaemia (1.2%) and osteonecrosis of jaw-related events (0.6%). A history of any drug allergy was a statistically significant risk factor associated with the occurrence of ADRs. In the effectiveness analysis set (n = 815), the incidence of progression of bone erosion was 8.7%. Steinbrocker stage and initial steroid dose were statistically significant risk factors associated with the progression of bone erosion.Conclusion Denosumab demonstrated safety and effectiveness over a 2 year period in RA patients without any new safety concerns.