Predictive factors for effective selection of Interleukin-6 inhibitor and tumor necrosis factor inhibitor in the treatment of rheumatoid arthritis

Treatment of rheumatoid arthritis (RA) is aimed at long-term remission and inhibition of joint destruction by different biologic drugs. However, the choice of a particular biologic agent based on individual cases of RA remains unestablished. Interleukin-6 (IL-6) inhibitor and tumor necrosis factor (TNF) inhibitor are common biologics used for the treatment of RA. This study aimed to investigate predictive factors for effective selection of tocilizumab (IL-6 inhibitor) and etanercept (TNF inhibitor) in patients with RA. This is a retrospective cohort study. The 196 patients analyzed in this study were divided into four groups: tocilizumab treatment as the first biologic group (TCZ first, 42 patients), tocilizumab as second/ third biologic group (TCZ second, 34 patients), etanercept as the first biologic group (ETN first, 103 patients) and etanercept as second/third group (ETN second, 17 patients). Visual analog scale (VAS), clinical disease activity index (CDAI), and modified health assessment questionnaire (mHAQ) scores at the initiation of biologic treatment and after 6 months of tocilizumab and etanercept therapy were measured and compared to clinical parameters and radiographical parameters among the four groups. CRP, MMP-3, VAS, CDAI, and HAQ were improved after 6 months of treatment in all groups. Improvement of clinical outcomes was correlated with CRP value, duration of RA, and Sharp scores at the initiation of treatment. Multivariate analysis demonstrated improvement in CDAI was significantly associated with the yearly progression of erosion according to the Sharp score in TCZ first group (OR, 1.5; 95% CI, 1.03–2.07) and was negatively associated with the duration of RA (OR, 0.49; 95% CI, 0.29–0.86) at the initiation of treatment with ETN first group. We identified the predictive factors for effective selection of tocilizumab and etanercept treatment and established the effectiveness of tocilizumab for the patients with rapid progressive joint erosion and etanercept for the early administration from diagnosis of RA.