AB0297 THE LONG-TERM OBSERVATION OF PATIENTS WITH RHEUMATOID ARTHRITIS WHO ACHIEVED A BIO-FREE CONDITION WITH ADALIMUMAB.

Background:Biological disease-modifying antirheumatic drugs (bDMARDs) caused a paradigm shift in the treatment of rheumatoid arthritis (RA). However, their high cost is a burden for patients and the national medical economy.Objectives:To analyze the long-term outcomes of patients with RA who achieved a bio-free condition (BF) with adalimumab (ADA).Methods:We followed 25 patients (male 6, female 19) who discontinued ADA with clinical remission (CR), and one female with a low disease activity (LDA), over 19.4 ±7.8 months of ADA treatment1). At the introduction of ADA, the average age was 51.2 ± 11.9 years old, and the average disease duration was 45.1 ± 48.4 months. The disease activity measured by disease activity score based on C-reactive protein (DAS28-CRP) was defined as follows: CR, <2.3; LDA, 2.3 - 2.7; moderate DA, 2.7 -4.1; and high DA, > 4.1, since the DAS28-CRP tends to be lower than the DAS28-based on the erythrocyte sedimentation rate in Japanese patients2).Results:We lost one patient with a transfer to another hospital. Four patients re-started ADA due to flare (DAS28-CRP>2.7) but achieved CR (in BF) again with the intensification of the treatment (dose increase or initiation of prednisolone [PSL] and/or conventional synthetic [cs] DMARDs such as tacrolimus or iguratimode). The DAS28-CRP significantly decreased from 3.45 ± 1.32 at base line (BL) to 1.55 ± 0.41 (p<0.0001) at BF. It remained 1.59 ± 0.59 (n=25) at 24 months after BF, 1.56 ± 0.39 (n= 20) at 48 months, 1.8 ± 0.7 (n=11) at 60 months. At the last observation, every patient remained in CR up to 84 months (n=2, Figure 1). The modified health assessment questionnaire score significantly decreased from 0.42 ± 0.46 (BL, n=19) to 0.02 ± 0.05 (p<0.002) at BF. It remained 0.03 ± 0.07 (n=19) at 24 months and 0.06 ± 0.14 (n=14) at 48 months, 0.04 ± 0.08 at 60 months (n=9). The PSL dose (mg/day) decreased from 3.2 ± 3.3 (BL) to 2.2 ± 2.8 at BF and 2.04 ± 2.13 (n=25) at 24 months, 1.73 ± 1.9 (n=20) at 48 months, and 1.6 ± 2.3 (n=11) at 60 months, but there were no significant changes. The methotrexate (MTX) dose (mg/week) increased from 10.1 ± 2.9 (BL) to 10.6 ± 2.6 (p< 0.78) at BF, 10.4 ± 3.3 (n=25) at 24 months, 10.7 ± 3.4 (n=20) at 48 months, 10.4 ± 3.1 at 60 months (not significant). The number of csDMARDs significantly increased from 0.8 ± 0.6 (BL) to 1.3 ± 0.9 (p<0.001, at BF), 2.56 ± 0.94 (n=25) at 24 months, 1.6 ± 1.01 (n=20) at 48 mnths, and 1.6 ± 2.3 at 60 months (n=11, Figure 2).Conclusion:BF can be sustained with an adequate dose of MTX and combination of csDMARDs.References:[1]Ito S, et al. An analysis of the biological disease-modifying antirheumatic drug-free condition of adalimumab-treated rheumatoid arthritis patients. Intern Med 58: 511-519, 2019[2]Inoue E, et al. Comparison of Disease Activity Score (DAS)28-erythrocyte sedimentation rate and DAS28- C-reactive protein threshold values. Ann Rheum Dis. 66:407-409, 2007.Disclosure of Interests:Satoshi Ito Speakers bureau: Abbvie,Eisai, Shunsuke sakai: None declared, Yoichi Kurosawa: None declared, Daisuke Kobayashi: None declared, Ryo Okabayashi: None declared, Asami Abe: None declared, Hiroshi Otani: None declared, Kiyoshi Nakazono: None declared, Akira Murasawa: None declared, Ichiei Narita: None declared, Hajime Ishikawa: None declared