Prediction of DAS28-ESR remission at 6 months by baseline variables in patients with rheumatoid arthritis treated with etanercept in Japanese population

Abstract

We tried to determine which baseline variables are responsible for remission induction at 6 months in unselected rheumatoid arthritis (RA) patients of Japanese population treated with etanercept. One hundred forty-one patients with RA who were administered etanercept were registered. Thirty-four patients were started on etanercept monotherapy, 60 patients on cotherapy with methotrexate (MTX) (MTX cotherapy), and 47 patients on cotherapy with other non-MTX nonbiologic disease-modifying antirheumatic drugs (DMARDs) (non-MTX cotherapy). None of the patients were treated with both MTX and non-MTX nonbiologic DMARDs at entry. Outcome was set as achievement of disease activity score 28 (DAS28)-ESR remission at 6 months. We examined association of gender, DAS at baseline, MTX cotherapy at baseline, non-MTX cotherapy at baseline, and prednisolone use at baseline with achievement of remission at 6 months by logistic regression analysis. All subjects were classified as having high (N = 109) or moderate disease activity (N = 32) at entry. One hundred twenty out of 141 patients (85.1%) continued treatment with etanercept at 6 months. Continuation rate was statistically higher in MTX cotherapy (93.3%) compared with etanercept monotherapy (73.5%), and tended to be higher than with non-MTX cotherapy (85.1%). Logistic regression analysis identified that MTX cotherapy at entry and moderate disease activity at entry were independent variables for remission induction at 6 months. Accordingly, DAS28-ESR at 6 months was significantly lower with MTX cotherapy as compared with etanercept monotherapy or non-MTX cotherapy. To a lesser extent, DAS28-ESR with non-MTX cotherapy at 6 months was lower than with etanercept monotherapy. In this study of unselected patients, use of MTX and moderate disease activity at entry were associated with higher likelihood of response to etanercept. Non-MTX nonbiologic DMARDs may be an alternative in RA patients administrated etanercept who are intolerant to MTX.