Maintenance of low disease activity and remission with etanercept-disease-modifying antirheumatic drug (DMARD) combination therapy compared with treatment with DMARDs alone in Latin American patients with active rheumatoid arthritis: Subset analysis of a randomized trial.

BACKGROUND: Current guidelines on the treatment of rheumatoid arthritis (RA) recommend early therapy targeting the achievement of low disease activity (LDA) or clinical remission. Little published information is available on the success of this treatment strategy in Latin America. In a subset analysis of patients from Latin America, we compared efficacy maintenance with etanercept 50 mg once weekly (ETN50) versus placebo (PBO), on a background of methotrexate (MTX) ±â€Šother non-biologic, disease-modifying antirheumatic drugs, in patients with moderate-to-severe RA who had achieved LDA with ETN50. METHODS: In the Treat-to-Target trial, adult patients with active RA nonresponsive to MTX were treated with ETN50 for 24 weeks (Period 1). Patients achieving LDA were randomized to receive ETN50 or PBO for 28 additional weeks (Period 2). The proportion of patients maintaining LDA at week 52 and other efficacy and quality-of-life measures were assessed. Descriptive statistics are presented using last observation carried forward imputation of data. RESULTS: Of the 64 patients from Latin America treated in Period 1, 61 (95.3%) achieved LDA. Among patients receiving ETN50, 13/34 remained in LDA and 6/14 maintained remission at week 52 versus 6/27 and 4/10 patients receiving PBO. The median time to flare was 113 days and 33 days for the ETN50 and PBO groups, respectively. In the overall population, adverse events were reported in 37% and 43%, serious adverse events in 1% and 4%, and serious infections in 0% and 2% of patients in the ETN50 and PBO groups, respectively. CONCLUSIONS: In patients with RA from Latin America, continuing treatment with ETN50 after achieving LDA appears to result in a higher proportion of patients maintaining LDA and remission compared with switching to PBO. CLINICALTRIALS. GOV REGISTRATION: NCT01578850.

Incidence of Antidrug Antibodies in Rheumatoid Arthritis Patients From Argentina Treated With Adalimumab, Etanercept, or Infliximab in a Real-World Setting.

BACKGROUND: Biologic agents may induce immune responses that could impact drug action. OBJECTIVES: The aims of this study were to assess antidrug antibodies (ADAs) in patients with rheumatoid arthritis (RA) from Argentina treated with etanercept, adalimumab, or infliximab at a single visit and correlate it with efficacy outcomes. METHODS: In this subset analysis of a noninterventional, multinational, cross-sectional study (NCT01981473), adult patients with RA treated continuously for 6 to 24 months with etanercept, adalimumab, or infliximab were evaluated for ADAs and trough drug concentrations of 2 days or less prior to the next scheduled dose. Efficacy measurements included Disease Activity Score based on a 28-joint count-erythrocyte sedimentation rate, low disease activity, and Health Assessment Questionnaire-Disability Index. Targeted medical history of injection site/infusion reactions, serum sickness, and thromboembolic events were reported. RESULTS: Baseline demographics, disease characteristics, and duration of treatment of the 119 patients (etanercept: n = 54, adalimumab: n = 52, infliximab: n = 13) were similar across all groups. No etanercept-treated patient tested positive for ADAs compared with 19 (36.5%) of 52 patients and 4 (30.8%) of 13 patients treated with adalimumab and infliximab, respectively. In adalimumab- and infliximab-treated patients, ADA presence correlated negatively with trough drug levels. A greater proportion of ADA-negative patients achieved Health Assessment Questionnaire-Disability Index of 0.5 or less and had better composite efficacy measures compared with ADA-positive patients. The rate of targeted medical events reported was low. CONCLUSIONS: In this subset analysis, RA patients from Argentina treated with adalimumab or infliximab, but not etanercept, tested positive for ADAs. Antidrug antibody-negative patients showed a tendency toward better clinical outcomes compared with ADA-positive patients.