SAT0134 Clinical Efficacy of Abatacept in Rheumatoid Arthritis Patients with Prior Use of Tocilizumab; Results from Japanese Multicenter Registry System TBCR
Authors: S. Hirabara, T. Kojima, N. Takahashi, M. Hanabayashi, K. Terabe, Y. Yoshioka, N. Ishiguro
Journal: Annals of the Rheumatic Diseases (2013)

<h3>Background</h3> Abatacept (ABT) is the first member of a new class of biologic agents for rheumatoid arthritis (RA) treatment to inhibit T-cell activation by binding to CD80/86 and modulating its interaction with CD28. The ATTAIN and ARRIVE studies previously demonstrated the efficacy of ABT in the patients with an inadequate response to anti-TNF agents. However, there has been no report describing the ABT efficacy in the patients with prior use of TCZ. <h3>Objectives</h3> The aim of this study was to examine the clinical efficacy of ABT therapy in the patients with prior use of TCZ, as well as TNF inhibitors. <h3>Methods</h3> 151 RA patients treated with ABT for longer than 52 weeks were included, from the 282 patients with ABT therapy in the Tsurumai Biologic Communication Registry (TBCR), which is the retrospective multicenter registry for RA patients taking biologics. They were divided into three groups: Switching from TCZ (TCZ switch, n = 16), Switching from TNF inhibitors (TNFi switch, n = 65), and Bio-naïve (n = 70). The changes of clinical parameters were studied at 0, 4, 12, 24, and 52weeks. We also studied proportions of patients achieving EULAR response criteria and retention rates of ABT treatment at 52 weeks. <h3>Results</h3> As shown in figure 1, patient retention rate of ABT therapy in the TCZ switch group and the TNFi switch group showed no statistically difference to the Bio-naïve group (68.8 vs 73.8% vs 84.3%). Interestingly, three patients in the TCZ switch group (18.8%) withdrew from ABT therapy within 12 weeks due to insufficient efficacy. As shown in figure 2, both TJC and SJC showed significant decreasing already at 4 weeks in the TCZ switch group similarly to other two groups. However, ESR was significantly flared up at 4 weeks and gradually decreased to the baseline value at 52 weeks. Moreover, the patient global assessment (VAS-GH) did not show significant improvement until week 24. <h3>Image/graph</h3> <h3>Conclusions</h3> The patient retention rate in the TCZ switch group appeared to be relatively low probably due to the flare up of inflammation markers and patient dissatisfaction. However, objective indices of joint inflammation (SJC and TJC) were quickly improved at 4 weeks and importantly there was only one case of discontinuation after 24 weeks in the TCZ switch group. Although ABT therapy would be essentially appropriate treatment option, it sometimes takes a time to demonstrate sufficient efficacy of ABT when switching from TCZ. It is quite natural that ESR and CRP flares up after the discontinuation of TCZ because TCZ always masks them by inhibiting IL-6 pathway. Thus, we should make decision carefully about clinical efficacy of ABT especially in the patients with prior use of TCZ. <h3>References</h3> Genovese MC, et al. Annals of the rheumatic diseases 2008;67:547–54. Schiff M, et al. Annals of the rheumatic diseases 2009;68:1708–14. <h3>Disclosure of Interest</h3> None Declared