BackgroundDetermining the optimal, patient-tailored biologic agent is a new challenge for future guidelines in rheumatoid arthritis (RA) management. Recent studies demonstrated that anti-citrullinated protein antibody (ACPA) -positive patients have better disease activity improvement with abatacept (ABA), yet validation studies are in need.ObjectivesTo investigate disease activity changes after treatment with ABA versus TNF inhibitors (TNFi) in Korean ACPA-positive, RA patients.MethodsData of RA patients were obtained from the Korean College of Rheumatology Biologics Registry (KOBIO). ACPA-positive patients who were treated with ABA and TNFi were selected through propensity score matching (1:2, calliper=0.2*SD). Clinical outcomes including CDAI changes at the first year of therapy were evaluated, and adjusted drug survival in each group was analysed.ResultsThe baseline characteristics of the ABA (n=97) and TNFi (n=194) groups were comparable. The CDAI reduction after 1 year treatment was significant in the ABA group compared with patients who received TNFi (−16.78 versus −13.61, p=0.0198) [figure 1]. This was confined when used as the first-line agent (p=0.0213). Proportion of remission and low disease activity in ABA was significant as well (p=0.041). Patients with the lower tertile of ACPA titers treated with ABA had the most significant CDAI reduction compared with the TNFi group (p=0.0201). Drug retention rate (median follow-up 48 months) of ACPA-positive ABA users was also notable compared with TNFi yet did not meet statistical significance (adjusted hazard ratio 0.774, p=0.086).ConclusionsOur data further support that ACPA could also be an important marker to help determine first-line biologic agent of choice among the armamentarium of biologic therapy for RA patients.AcknowledgementsWe would like to thank Song Wha Chae and Evo Alemao for their input and support.Disclosure of InterestNone declared

Background:Previous studies have showed that response rate to biologic therapy in patients with rheumatoid arthritis (RA) are lower in those who had prior exposure to multiple biologic agents compared with first-time users. However, most of these studies targeted on patients undergoing anti-TNF therapy.Objectives:To investigate the treatment response of RA patients using intravenous tocilizumab (TOC) as the first biologic agent, comparing with those who had prior exposure to other biologic agentsMethods:Data of RA patients treated with TOC were obtained from the Korean College of Rheumatology Biologics Registry (KOBIO). Patients were grouped as first (1st)-line, second (2nd)-line, and third or more (≥3rd)-line users. Clinical outcomes including SDAI changes at the first year and second year of TOC therapy were evaluated, and subsequent switching to another biologic agent and its associated factors were analyzed using the Cox proportional hazard model.Results:A total of 408 patients were included in the study; 1st-line (n = 258), 2nd -line (n = 95), ≥3rd -line (n = 55) users. The mean age was 54.0 years, and mean disease duration of 8.2 years. At baseline, mean SDAI was 30.0, and 7.1% of patients were treated without a concomitant conventional DMARD, which increased to 21.6% at the end of the second year. The clinical response of related parameters in 1st -line TOC users were more robust than the 2nd -line or ≥3rd -line users, and greater proportion of 1st -line users achieved remission or low disease activity at the second year (p=0.00291) (figure). In addition, switching to another agent was more frequent in the 2nd -line or ≥3rd -line users within 2 years (1st, 2nd, ≥3rd -line users, 4.7%, 15.1%, 11.1%, respectively). A multivariate analysis revealed that higher baseline SDAI (HR 1.1018, p=0.00680) and multiple prior exposure to biologics (HR 2.5751, p=0.0139) were predictors of subjects switching to other agents.Conclusions:Amongst RA patients with high disease activity who receive TOC, patients naïve to biologics have better treatment response and lower switch rates after two years.Reference[1]Karlsson JA, et al. Treatment response to a second or third TNF-inhibitor in RA: results from the South Swedish Arthritis Treatment Group Register. Rheumatology2008;47:507–13.Disclosure of Interest:None declared