Background In treating RA patients with etanercept (ETN) or adalimumab (ADA), influence of concomitant disease-modifying antirheumatic drugs (DMARDs) (methotrexate [MTX], bucillamine, salazosulfapyridine, tacrolimus, and mizolibin) and prednisolone (PSL) on biologic inefficacy still remains controversial.
Objectives The objective of this study is to compare the effect of DMARDs and PSL on biologic inefficacy of ETN and ADA, and to investigate the index of subcutaneous anti-TNF biologics selection in RA patients.
Methods 284 RA patients who were followed-up more than 6 months after starting ETN (184 patients / 164 female 20 male / age 55.3y / disease duration 9.5y / pre DAS28-CRP 4.1 / 1st Bio 148 / 2nd or later Bio 36) or ADA (100 patients / 87 female 13 male / age 51.6y / disease duration 9.9y / pre DAS28-CRP 4.2 / 1st Bio 60 / 2nd or later Bio 40) were enrolled, and correlation between biologic inefficacy and clinical parameters including concomitant DMARDs and PSL were evaluated.
Results Drug inefficacy was monitored in 20.7% of ETN (1st Bio 16.9% / 2nd or later Bio 36.1%) and 28.0% of ADA (1st Bio 21.7% / 2nd or later Bio 37.5%) (ETN vs. ADA; P=0.16). Mean treatment continuation duration was 32.9 months in ETN (inefficacy group 21.6 months vs. efficacy group 42.7 months) and 15.5 months in ADA (inefficacy group 9.8 months vs. efficacy group 20.8 months), and treatment continuation duration of inefficacy group was significantly longer in ETN compared to ADA (P<0.01). In ETN, inefficacy group showed higher dose of concomitant PSL (7.0 vs. 4.4 mg/day; P<0.001) and higher pre DAS28-CRP (4.5 vs. 4.1; P<0.05) compared to efficacy group. In ADA, inefficacy group showed lower dose of concomitant MTX (4.6 vs. 7.0 mg/week; P<0.01) and higher pre DAS28-CRP (4.5 vs. 3.9; P<0.01) compared to efficacy group. As for concomitant dose of MTX, when treated less than 6mg/week, inefficacy rate was significantly higher in ADA (36.5%) compared to ETN (21.0%) (P<0.05). However, those who were treated more than 8mg/week MTX, inefficacy rate was similar (ETN 19.0% vs. ADA 18.8%). In ETN, inefficacy rate was 8.2% when concomitant PSL was ≤4mg/day, while it was significantly higher (28.8%) in those who were treated more than ≥5mg/day PSL (P<0.001). PSL showed no significant correlation with inefficacy rate of ADA. Age, sexuality, body mass index, duration of disease, and dose of other DMARDs did not show any significant correlation with inefficacy rate of ETN and ADA.
Conclusions When choosing ETN or ADA in the treatment of RA, concomitant MTX ≥8mg/week or PSL ≥5mg/day should be taken into consideration to avoid drug inefficacy.
Disclosure of Interest None Declared