THU0086 Seropositivity and response to RTX: Data from the cererra collaboration

Background Predictors of response to biologic therapy in rheumatoid arthritis (RA) are needed to achieve a more individualized therapy. Seropositivity has been associated with better response to rituximab (RTX). Objectives To assess the 6-month response to the first RTX course in RA according to RF and ACPA status. Methods Ten European registries submitted anonymized datasets from RA patients who had started RTX, and datasets were pooled and analysed. Chi-square test for comparison of categorical variables and t-test for continuous data were used. Predictors of response were identified by logistic regression analysis. Results 3266 patients were included in the cohort. 79.9% of patients were RF (+) (2041 out of 2553) and 73.2% were ACPA (+) (877 out of 1198). 718 patients were double positive (DP) and 147 double negative (DN). 2200 patients were RF (+) and/or ACPA (+). Improvements of DAS28 (ΔDAS28) at 6 months were significantly better for RF (+) than RF (–) patients as well as for ACPA (+) than ACPA (–), DP vs. DN and RF and/or ACPA (+) vs. DN (table 1). A significantly higher percentage of ACPA (+) and DP patients achieved EULAR Good Response at 6 months compared to ACPA (–) and DN, respectively (table 1). The completeness of data was very similar for seropositive and seronegative patients, with the percentage of missing data at 6 months being approximately 50% in all groups. A significantly higher percentage of seronegative patients received retreatment by 6 months than seropositive patients. In univariate analyses adjusted for age and gender ACPA positivity (OR=2.03, p=0.016) and DP (OR=2.43, p=0.03) but not RF positivity (OR=1.53, p=0.07) predicted EULAR good response to therapy with RTX at 6 months after the first treatment. Conclusions In this large observational cohort of RA patients treated with RTX, seropositive patients achieved significantly greater reductions in DAS28 at 6 months compared to seronegative patients. Baseline ACPA positivity may be a better predictor for good response to RTX than RF positivity. Disclosure of Interest None Declared