AB0377 Differences in Baseline Predictive Factors for Remission at 52 Weeks by Concomitant MTX Use during Tocilizumab Treatment Using Propensity Score Matched Groups
Authors: T. Kojima, S. Asai, N. Takahashi, Y. Yabe, Y. Hirano, Y. Kanayama, A. Kaneko, T. Takemoto, N. Asai, T. Watanabe, K. Funahashi, M. Hayashi, N. Ishiguro
Journal: Annals of the Rheumatic Diseases (2016)

<h3>Background</h3> In the treatment of rheumatoid arthritis, concomitant use of methotrexate (MTX) should be a critical factor for decision of treatment now. Tocilizumab, IL-6 receptor antibody has been reported to have good efficacy even without concomitant MTX in clinical trials and observational study. However, there is an important clinical question that concomitant MTX use could have any impacts on predictive factors of achievement of good clinical goal. <h3>Objectives</h3> To explore the differences in predictive factor for achievement of remission by concomitant MTX use during TCZ treatment. In observational study, it is important to match background of the patients for comparison. We used propensity score matching, which is useful statistical tool for comparison in clinical practice. <h3>Methods</h3> This study included 240 RA patients who received TCZ (concomitant MTX use: MTX(+) 117: no use: MTX(−) 123) in the multicenter observational cohort (Tsurumai Biologics Communication Registry; TBCR, 2827cases treated with biologics were registered until 2014). We prepared matched groups by concomitant MTX use using propensity score (matched factors, age, sex, previous biologics use, glucocorticoid use, Steinbrocker stage and class, disease duration, DAS28 at baseline). We determined the baseline predictive factors for remission (DAS28) at week 52 by the matched groups using multivariate logistic regression analysis. Especially, association of DAS28 at baseline to achievement of remission was compared using area under the curve (AUC) of ROC curve. <h3>Results</h3> Sixty-nine patients were matched between groups. Baseline characteristics were shown in Table 1. Rate of remission was 55.2% in MTX(+) group and 44.8% in MTX(−) group (p=0.39). Independent predictive factors at baseline for remission were disease duration [OR:0.90, 95%CI (0.83–0.97)] in MTX(+) group while DAS [OR:0.49, 95%CI (0.29–0.83)] in MTX(−) group based on multivariate analysis. We also showed significant difference in association of DAS at baseline to remission between groups using AUC of ROC curve (AUC 0.59 vs 0.73, Fig. 1). Interestingly, after matching baseline characteristics, achievement of remission in MTX(−) group depended on disease activity at baseline while that in MTX(+) group did not. The cut-off value of DAS28 at baseline for achievement of remission was 4.87 (sensitivity 0.61, specificity 0.84) in MTX(−) group. <h3>Conclusions</h3> There is significant difference in baseline predictive factors for good clinical results by concomitant MTX use during TCZ treatment. The results should be taken into consideration to predict clinical response in clinical practice. <h3>Disclosure of Interest</h3> T. Kojima Speakers bureau: Mitsubishi Tanabe Pharma, Takeda Pharma, Eisai Pharma, AbbVie, Bristol-Myers Squibb, and Pfizer, Janssenn Pharmaceutical Companies, Astellas Pharma and Chugai Pharma., S. Asai: None declared, N. Takahashi Speakers bureau: Abbvie Japan Co. Ltd, Eisai Co. Ltd, UCB Japan Co. Ltd, Mitsubishi Tanabe Pharma Corporation, Takeda Pharmaceutical Company Ltd, Pfizer Co. Ltd, Chugai Pharmaceutical Co. Ltd, Janssen Pharmaceutical K.K., and Bristol-Myers Squibb Co. Ltd., Y. Yabe: None declared, Y. Hirano Speakers bureau: Abbvie Japan, Eisai, Mitsubishi Tanabe Pharma, Pfizer, Chugai Pharmaceutical, and Bristol-Myers Squibb., Y. Kanayama: None declared, A. Kaneko Speakers bureau: Mitsubishi Tanabe Pharma, Takeda Pharma, Eisai Pharma, Chugai Pharma, Abbott, Bristol-Myers Squibb, UCB, Janssen, and Pfizer, T. Takemoto: None declared, N. Asai: None declared, T. Watanabe: None declared, K. Funahashi: None declared, M. Hayashi: None declared, N. Ishiguro Grant/research support from: Daiichi Sankyo, Takeda Pharmaceutical, Hisamitsu Pharmaceutical, Otsuka Pharmaceutical, Taisho Toyama Pharmaceutical, Kaken Pharmaceutical, Eisai, Janssen Pharmaceutical, Bristol-Myers Squibb, AbbVie, Chugai Pharmaceutical, Mitsubishi Tanabe Pharmaceutical, Astellas Pharma, and Pfizer Japan, Speakers bureau: Daiichi Sankyo, Takeda Pharmaceutical, Hisamitsu Pharmaceutical, Otsuka Pharmaceutical, Taisho Toyama Pharmaceutical, Kaken Pharmaceutical, Eisai, Janssen Pharmaceutical, Bristol-Myers Squibb, AbbVie, Chugai Pharmaceutical, Mitsubishi Tanabe Pharmaceutical, Astellas Pharma, and Pfizer Japan