Predictive factors for achieving low disease activity at 52 weeks after switching from tumor necrosis factor inhibitors to abatacept: results from a multicenter observational cohort study of Japanese patients.
This study aimed to identify predictive factors for achieving low disease activity (LDA) in rheumatoid arthritis (RA) patients switching from tumor necrosis factor inhibitors (TNFis) to abatacept (ABT). Patients who were registered in the multicenter observational Tsurumai Biologics Communication Registry (TBCR) were enrolled in this study. Predictive factors for LDA achievement at each time point were determined by univariate and multivariate logistic regression analyses. The cutoffs of 28-point count Disease Activity Score (DAS28)-C-reactive protein (CRP) and ΔDAS28-CRP from baseline up to 24 weeks for LDA achievement at 52 weeks were explored using receiver operating characteristic (ROC) curves. Of 2771 RA patients registered until 2013, 76 with moderate or high disease activity were selected. Twenty-six percent of the patients achieved LDA. Multivariate analysis confirmed that DAS28-CRP at 12 weeks and ΔDAS28-CRP from baseline to 12 weeks were independent factors for LDA achievement at 52 weeks [odds ratio (OR) 0.26, 95% confident interval (CI) (0.12-0.56), OR 0.25, 95% CI (0.11-0.57), respectively]. The best cutoff values of DAS28-CRP at 12 weeks and ΔDAS28-CRP from baseline to 12 weeks for LDA at 52 weeks were 3.9 (sensitivity 0.85, specificity 0.78) and -0.97 (sensitivity 0.70, specificity 0.70), respectively. Seventy-one percent of patients who achieved both of these cutoff values at 12 weeks achieved LDA at 52 weeks. Our findings suggest that the clinical course up to 12 weeks is important for predicting long-term outcomes when switching from TNFis to ABT.