AB0231 RHEUMATOID ARTHRITIS PATIENTS TREATED WITH ABATACEPT AT A COMMUNITY RHEUMATOLOGY CLINIC AND WHO ARE POSITIVE FOR ANTICYCLIC CITRULLINATED PEPTIDE ANTIBODIES HAVE MORE SUSTAINED CLINICAL RESPONSES THAN PATIENTS NEGATIVE FOR THE MARKER
Authors: C. Wiesenhutter, V. Hayden
Journal: Annals of the Rheumatic Diseases (2020)

Background: Treating Rheumatoid Arthritis (RA) patients to target (T2T) has been shown to result in better outcomes in patients with RA [1]. There are now a number of therapeutic options to accomplish this goal, but determining which agent to select for each individual has not been defined. Objectives: The purpose of this post hoc analysis was to assess if Anticyclic Citrullinated Peptide Antibody (anti-CCP) status effects outcomes following treatment of RA patients with Abatacept. Methods: Patients at a community based rheumatology clinic undergo disease activity measure assessments on a routine basis as part of the implementation of T2T strategy with ongoing assessments on at least a yearly basis. Over the past 15 years there have been 78 patients initiated on treatment with Abatacept at this clinic. Anti-CCP and Rheumatoid factor status is routinely obtained when patients are first seen in the clinic. A patient was considered to be Anti-CCP positive if the test was 20 u/ml or greater. As a comparison, the 53 patients in the clinic started on Tofacitinib were also analyzed. The difference in sustained clinical response rates between seropositive and seronegative patients were determined for these two groups. Sustained clinical response was defined as remaining on treatment for at least three years. Patients who were lost to follow up or who died, while on treatment for less than three years, were not included. Statistical analysis was performed with IBM SPSS V. 25 using chi square tests and logistic regression incorporating pretreatment gender, DAS28CRP, CDAI, rheumatoid factor, Multi-biomarker disease activity score, and a power Doppler joint count. Results: Fifty anti-CCP positive patients and twenty-two anti-CCP negative patients treated with Abatacept were clinically assessed and results of the post hoc analysis are shown in Table one. Chi square risk estimate 4.61 Clinical sig p= 0.01. Logistic regression: Unadjusted Risk ratio (95% CI) 4.86 (1.54, 8.18) Clinical sig p= .01. Adjusted Risk Ratio (95% CI) 4.21 (1.23, 7.19.) Clinical sig = 0.03. Results of the post hoc analysis for patients treated with Tofacitinib are shown in Table two. Chi square risk estimate 1.75 (not clinically significant.) Unadjusted Risk 1.70 (not clinically significant). Adjusted Risk 1.42 (not clinically significant). CCP * Responder Crosstabulation Abatacept Responder Total yes no CCP ccp positive Count 29 21 50 % within CCP 58.0% 42.0% 100.0% ccp negative Count 5 17 22 % within CCP 22.7% 77.3% 100.0% Total Count 34 38 72 % within CCP 47.2% 52.8% 100.0% Conclusion: Rheumatoid Arthritis patients who are Anti-CCP positive and who are treated with Abatacept in a community rheumatology clinic have a significantly greater number of sustained clinical responses than patients who are Anti-CCP negative. CCP * Responder Crosstabulation Tofacitinib Responder Total yes no CCP ccp positive Count 21 8 29 % within CCP 72.4% 27.6% 100.0% ccp negative Count 9 6 15 % within CCP 60.0% 40.0% 100.0% Total Count 30 14 44 % within CCP 68.2% 31.8% 100.0% This difference for patients treated with Tofacitinib was not clinically significant in this clinic, though a higher percentage of Anti-CCP positive patients treated with Tofacitinib responded (72% vs 60%). Anti-CCP positivity could be used as a clinical marker to select patients with rheumatoid arthritis to be treated with Abatacept. References: [1]Smolen, J. et al. Ann. Rheum Dis 2010:69;638-643 Disclosure of Interests: None declared