Objectives: To evaluate drug survival (continuation rates on drug) of anti-TNF agents in juvenile idiopathic arthritis (JIA) and predictors for treatment discontinuation.
Methods: Retrospective observational study on JIA patients taking etanercept (n=105) or infliximab (n=104) with at least one-year follow-up. Kaplan-Meier curves and logrank statistics were used to compare treatments, and proportional hazards model to assess risk factors for discontinuation.
Results: Etanercept versus infliximab treatment survival was at 12 months 83% vs. 80%, at 24 months 68% vs. 68%, at 36 months 64% vs. 53%, at 48 months 61% vs. 48% (p=0.194), respectively. Reasons to discontinue the first biologic treatment were inefficacy (etanercept 28% vs. infliximab 20%, p=0.445), adverse events (7% vs. 22%, p=0.002) or inactive disease (10% vs. 16%, p=0.068). Females [hazard ratio (HR) 2.8, 95% confidence intervals (CI) 1.3 to 5.8], patients with systemic JIA (sJIA), HR 7.8 (95% CI 1.7 to 34.9) or those taking infliximab (HR 2.0, 95% CI 1.2-3.3) were in higher risk for treatment discontinuation. One-third of the patients were switched to the second anti-TNF therapy, which was discontinued less frequently than the first. At 12 months treatment survival of etanercept was 60%, infliximab 58%, and adalimumab 66% as the second-line anti-TNF therapy.
Conclusions: Although infliximab was discontinued more often than etanercept because of adverse events, during a 48-month follow-up the overall treatment survival of etanercept and infliximab as the first biologic agent in JIA was comparable. A switch from one anti-TNF agent to another appears a reasonable therapeutic option.