FRI0321 The Dynamics of Response to Rituximab in Rheumatoid Arthritis Patients with Moderate Disease Activity and Inadequate Response to Inhibitors of Tumor Necrosis Factor. Data from 3-Year REPEAT Study
Authors: I. Ancuta, C. Codreanu, R. Ionescu, A. Balanescu, E. Rezus, M. Suta, P. Ciurea, M. Milicescu, D. Nemes, C. Ancuta, M. Bojinca, M. Parvu, H. Popoviciu
Journal: Annals of the Rheumatic Diseases (2014)

<h3>Background</h3> In recent years, emphasis has shifted in rheumatoid arthritis (RA) to early intervention in the disease course. We have shown that patients with MDA should be further divided in three subgroups (MDA1,2 and 3) according to DAS28 values, MDA1 <i>ΔDAS28&lt;1.2</i> and <i>3.2&lt;DAS28&lt;3.5</i>, MDA2 <i>3.5&lt;DAS28&lt;3.8</i> and MDA3 <i>3.8&lt;DAS28&lt;5.1</i>. and those with 3.8&lt;DAS28&lt;5.1 (MDA 3) have a response similar to HDA with most rapid loss of treatment efficacy and immediate evolution towards HDA. For this reason, in current practice in Romania, for MDA3 patients second line therapy is considered at first evaluation (6 weeks). All MDA patients, we recommend patient evaluation and tight control in the first 1-3 months after anti-TNF treatment initiation, according to ACR/EULAR criteria and ACR 2012 treat to target guidelines. <h3>Objectives</h3> To describe the dynamics of response in MDA patients in terms of MDA1, MDA 2 and MDA 3 subgroups after the switch to rituximab (RTX) second line after the failure of TNF inhibitors. <h3>Methods</h3> REPEAT is an open-label, multicenter, prospective observational local study. From 1087 patients with active RA and inadequate response to at least one TNF inhibitor treated with initial RTX, for this analysis were selected only those patients with MDA at baseline. Patients were evaluated at baseline and at 6, 12, 18, 24, 30 and 36 months. The disease activity score DAS28 and ΔDAS28 calculated from baseline and between successive evaluations. Statistical analysis was performed using STATA SE 11.0 software and ANOVA, Nptrend and Kruskal-Wallis tests performed. <h3>Results</h3> From a total 1087 patients in study, 284 were with MDA at baseline evaluation before RTX treatment initiation. They were further split in MDA1 (47), MDA2 (31) and MDA3 (206) according to criteria described above. The dynamics of responses (%) across evaluations at baseline and at 6, 12, 18, 24, 30 and 36 months has shown a linear and constant increase of responders, for LDA group 0; 20.49; 26.67; 33.18; 33.72; 30.89; 31.03 (p&lt;0.0001) and remission 0; 10.25; 23.1; 33.65; 42.44; 39.02; 48.28 (p&lt;0.0001) and a deep decrease of MDA3 subgroup from 72.54% at baseline to 8.62% at 36 months (p&lt;0.0001). From all 284, only 2.83% has been found with HDA at 6 months, but percentage decrease up to 0% at 24 months evaluations. For MDA2 and MDA1 the dynamics was in the same mode as in MDA3 group but less intense. <h3>Conclusions</h3> These findings support the decision to switch to RTX second line therapy the RA patients treated with TNF inhibitors and presenting a DAS value in (3.8-5.1) open interval, offering the opportunity to remission or LDA for patients in so called MDA3 subgroup. <h3>References</h3> Ancuta et al. Ann Rheum Dis 2013;72(Suppl3):218. <h3>Disclosure of Interest</h3> None declared <h3>DOI</h3> 10.1136/annrheumdis-2014-eular.2675