Predictors of response to etanercept-methotrexate treatment: a post hoc logistic regression analysis of a randomized, open-label study in Latin American patients with rheumatoid arthritis

Abstract

Abstract Background Determining potential predictors of clinical response would allow a more personalized rheumatoid arthritis (RA) treatment approach in heterogeneous populations such as Latin American (LA) patients. Methods Post hoc analysis to identify baseline characteristics predictive of clinical remission in response to treatment with etanercept (ETN) plus methotrexate (MTX) in LA patients with moderate to severe MTX-resistant RA. We report data from the group of patients who received ETN 50 mg/week plus MTX (ETN + MTX, n = 281) in a clinical trial consisting of an initial 24-week open-label phase, followed by a 104-week extension. Remission was defined as 28-joint Disease Activity Score with erythrocyte sedimentation rate (DAS28-ESR) score 28.5 kg/m2 (OR 3.24), disease duration > 3.7 years (OR 2.22), ESR ≤ 42 mm/h (OR 2.72), PGA ≤ 6 (OR 3.21), tender joint count ≤ 14 (OR 2.25), and total HAQ score ≤ 1.6 (OR 2.86). At Week 128, age ≤ 42 years (OR 2.21), SF-36 Mental Health Scale score > 39.6 (OR 2.16), White race (OR 4.07), > 18 swollen joints (OR 2.11), and VAS Pain ≤ 41 (OR 6.05) at baseline were the best subset of significant predictors of remission. Conclusions In LA patients with RA, younger age, higher BMI, longer disease duration, higher SF-36 Mental Health Scale score, higher swollen joint count, and overall lower disease activity predicted clinical response to ETN + MTX therapy. Trial registration: ClinicalTrials.gov Identifier: NCT00848354.