Background:Cervical lesions are known to occur at high frequency as a complication of rheumatoid arthritis (RA). Treatment with biological agents are more clinically effective than the DMARDs that were in use previously, in particular, with their efficacy in suppressing joint destruction having been emphasized. We reported the efficacy of infliximab, anti-tumor necrosis factor antibodies for suppressing the radiographic progression of RA cervical lesions at ACR2009, EULAR2010, 11, 12, 13, 14,16 and 18. However there is still few studies of efficacy of against RA cervical lesions of Abatacept (ABT) that inhibits T cell activation by binding to CD80/86.Objectives:To evaluate the efficacy of ABT for suppressing the radiographic progression of RA cervical lesions comparison with MTX for 2 years.Methods:We used ABT or MTX for treating Japanese patients with active RA who fulfilled the ACR criteria in 1987. The final study cohort of each 60 and 75 patients received continuous ABT and MTX treatment for at least 2 years. For evaluation of cervical lesions, the atlanto-dental interval (ADI), the space available for the spinal cord (SAC), and the Ranawat value were measured by plain lateral radiographs in the flexion position, at initiation and Year 1,2.Results:In the patients receiving ABT (n=60) and MTX (n =75), the number of female were each 48(80%) and 52(69%) cases(p=0.160). The mean age was 67.7 ± 12.9 and 63.6 ± 11.0 years old (p=0.004); disease duration was 16.7 ± 14.2 and 8.0 ± 9.5 years (p<0.001) and the mean dose of MTX was 8.4 ± 3.6 and 8.2 ± 2.9 mg/w (p=0.804). Clinical findings related to RA were as follows; CRP 2.2± 2.1 and 1.7± 2.3 mg/dl(p=0.008); ESR 47.2 ± 23.4 and 31.9 ± 21.8mm/h(p<0.001); MMP3 253 ± 280 and 223 ± 350ng/ml(p=0.003); the number of RF-positive 57(95%) and 60(80%) cases(p=0.011); DAS28-ESR 5.13 ± 0.99 and 4.30 ± 1.38 (p<0.001); ADI 3.6 ± 2.1 and 2.6 ± 1.6mm(p=0.003); SAC 18.5 ± 2.8 and 20.8 ± 2.5mm(p<0.001) and Ranawat value 14.4 ± 1.9 and 16.0 ± 1.5mm (p<0.001). The respective changes in cervical lesion parameters after 1 year were as follows: ADI: 0.20 ± 0.40 and 0.27 ± 0.45 mm (p = 0.367); SAC: −0.12 ± 0.32 and −0.17 ± 0.38 mm (p = 0.359); and Ranawat value: −0.15 ± 0.36 and −0.13 ± 0.34 mm (p = 0.783). The respective changes in cervical lesion parameters after 2 years were as follows: ADI: 0.35 ± 0.58 and 0.55 ± 0.70 mm (p = 0.099); SAC: −0.25 ± 0.47 and −0.45 ± 0.62 mm (p = 0.047); and Ranawat value: −0.23 ± 0.47 and −0.33 ± 0.55 mm (p = 0.293) in the patients receiving ABT and MTX (Fig. 1). The numbers of patients who did not showed progression in ADI, SAC and Ranawat value were each 42(70%) and 43(57%) cases(p=0.130); 46(77%) and 46(61%) cases(p=0.057) and 47(78%) and 53(71%) cases(p=0.313) after 2 years. Also the number who was able to suppress progression in all three parameters were each 42 cases (70%) receiving ABT and 43 cases (57%) receiving MTX (p=0.130) after 2 years (Fig. 2).Conclusion:This study suggested that ABT treatment can be used to suppress the progression of RA cervical lesions more than MTX treatment.Disclosure of Interests:Yasuhide Kanayama: None declared, Toshihisa Kojima Grant/research support from: Chugai, Eli Lilly, Astellas, Abbvie, and Novartis, Consultant of: AbbVie, Speakers bureau: AbbVie, Astellas, Bristol-Myers Squibb, Chugai, Daiichi-Sankyo, Eli Lilly, Janssen, Mitsubishi Tanabe, Pfizer, and Takeda, Yuji Hirano Speakers bureau: Tanabe-Mitsubishi, Pfizer, Eisai, Abbie, Chugai, Bristol-Meyers, Jansen, Astellas, UCB, Eli-Lilly, Asahikasei, Daiichi-Sankyo, Amgen, Nobunori Takahashi Speakers bureau: AbbVie, Asahi Kasei, Astellas, Bristol-Myers Squibb, Chugai, Daiichi-Sankyo, Eisai, Eli Lilly, Janssen, Mitsubishi Tanabe, Ono, Pfizer, Takeda, and UCB Japan, Yukiyoshi Oishi: None declared, Naoki Ishiguro Grant/research support from: AbbVie, Asahi Kasei, Astellas, Chugai, Daiichi-Sankyo, Eisai, Kaken, Mitsubishi Tanabe, Otsuka, Pfizer, Takeda, and Zimmer Biomet, Consultant of: Ono, Speakers bureau: Astellas, Bristol-Myers Squibb, Daiichi-Sankyo, Eli Lilly, Pfizer, and Taisho Toyama