ASSOCIATION BETWEEN RHEUMATOID FACTOR STATUS AND DISCONTINUATION OF TUMOR NECROSIS FACTOR INHIBITORS DUE TO INEFFECTIVENESS IN RHEUMATOID ARTHRITIS

Background: As for the treatment of rheumatoid arthritis (RA), the influence of rheumatoid factor (RF) positivity on the long-term efficacy of tumor necrosis factor inhibitors (TNFi) is controversial. Objectives: We conducted an exploratory study in a large cohort of RA patients to evaluate the relationship between RF status and the discontinuation of TNFi treatment due to ineffectiveness in a clinical setting. Methods: This study included bio-naïve RA patients enrolled in the Tsurumai Biologic Communication Registry in Japan. The crude comparison of TNFi discontinuation due to ineffectiveness between seropositive and seronegative patients was analyzed using the cumulative incidence function of competing events and Gray test. We assessed the associations between baseline patient characteristics and discontinuation of TNFi therapy due to insufficient response using Fine-Gray proportional hazard regression. Fine-Gray proportional hazard analysis considered competing events of interest, including insufficient response, adverse event, palliation, and personal reasons. Results: Demographic and clinical characteristics of each group are described in Table 1 . There was a higher discontinuation rate due to insufficient response in RF positive patients than in RF negative patients using Gray test (Figure). RF positivity was significantly predictive of the discontinuation of TNFi therapy due to ineffectiveness using Fine-Gray proportional hazard regression analysis after adjusting for baseline characteristics, including age, sex, stage, class, disease activity at baseline, methotrexate use, and prednisolone use ( Table 2 ). Conclusion: Using Fine-Gray proportional hazard regression, we demonstrated that RF positivity was related to a higher discontinuation rate of TNFi therapy due to ineffectiveness in bio-naïve RA patients. Table 1 Characteristics of RA patients at baseline by RF status. RF (n = 1151; 3407 patient-years) RF RF positive negative (n = 913) (n = 238) P † Age, years (SD) 56.6 (13.5) 53.1 (14.7) <0.001 Female, no. (%) 737 (80.8) 195 (82.3) 0.64 DAS28ESR (SD) 5.28 (1.33) 4.87 (1.38) <0.001 Stage I+II/III+IV, no. (%) 312/569 (35.4/64.6) 103/120 (46.2/53.8) 0.0032 Class I+II/III+IV, no. (%) 543/338 (61.6/38.4) 174/49 (78/22) <0.001 Current MTX treatment, no. (%) 584 (82.7) 191 (90.1) 0.009 Current PSL treatment, no. (%) 383 (58.1) 98 (51.0) 0.083 Data are presented as mean, unless otherwise stated. SD: standard deviation; RA: rheumatoid arthritis; RF: rheumatoid factor; MTX: methotrexate; PSL: prednisolone; DAS28ESR: Disease Activity Score in 28 joints calculated with erythrocyte sedimentation rate. † Chi-square test for categorical variables and t-test for continuous variables. Table 2 Fine-Gray proportional hazard regression. Model including RF status (n = 643) Variable HR (95% CI) P RF positive 1.73 (1.07-2.80) 0.023 Age at baseline 0.98 (0.97-0.99) 0.035 Sex (referent: male) 0.89 (0.58-1.38) 0.63 Methotrexate use 1.68 (0.96-2.96) 0.069 Prednisolone use 1.20 (0.83-1.75) 0.31 Stage III + IV (referent: I + II) 0.99 (0.98-1.01) 0.97 Class III + IV (referent: I + II) 1.00 (0.98-1.02) 0.67 DAS28ESR at baseline 1.31 (1.14-1.51) <0.001 Disclosure of Interests: Yoshikazu Ogawa: None declared, Nobunori Takahashi Speakers bureau: AbbVie, Bristol-Myers Squibb, Chugai, Eisai, Mitsubishi Tanabe, and Pfizer. YS has received speakers’ fees from Astellas, Bristol-Myers Squibb, and Ono, Toshihisa Kojima Grant/research support from: Chugai Pharmaceutical (Investigator Initiated Study), Novartis, Nippon Kayaku, Eli Lilly, Eisai, Speakers bureau: Chugai Pharmaceutical, Takeda Pharmaceutical, Pfizer, Eli Lilly Japan, Bristol Myers Squibb, Ono Pharmaceutical, Daiichi Sankyo, Astelas, UCB, Janssen Pharmaceutical, Tanabe Mitsubishi, Naoki Ishiguro Grant/research support from: AbbVie, Asahi Kasei, Astellas, Chugai, Daiichi-Sankyo, Eisai, Kaken, Mitsubishi Tanabe, Otsuka, Pfizer, Takeda, and Zimmer Biomet, Consultant for: Ono, Speakers bureau: Astellas, Bristol-Myers Squibb, Daiichi-Sankyo, Eli Lilly, Pfizer, and Taisho Toyama DOI: 10.1136/annrheumdis-2019-eular.4077Citation: Ann Rheum Dis, volume 78, supplement 2, year 2019, page A722Session: Rheumatoid arthritis - biological DMARDs (Scientific Abstracts)