Tumor necrosis factor (TNF) blockers are efficacious in clinical trials in rheumatic diseases. However, their efficacy in daily practice, depending on the specific diagnosis or the use of concomitant therapy, remains to be confirmed. Our objective was to evaluate TNF blocker retention rates and their predisposing factors in daily practice.
Retrospective evaluation of all TNF blocker therapies in one center. Retention rate was evaluated using a Kaplan-Meier survival data analysis technique in which the event was discontinuation of the drug due to inefficacy or toxicity with log-rank tests and a Cox proportional-hazards regression model.
From 1997 to 2004, 770 patients with inflammatory rheumatism received at least one TNF blocker; 142 received more than one agent (975 treatment courses: 493 etanercept, 335 infliximab, 147 adalimumab). The underlying disease was mainly rheumatoid arthritis (RA), found in 57.1% of patients, and spondyloarthropathies (SpA) in 37.7%. The percentage of patients receiving the same treatment at Month 12, 24, and 36 was 64.0%, 50.3%, and 39.4%, respectively. No difference between the 3 TNF blockers was found (p = 0.48). The retention rate was longer for the first treatment course [hazard ratio (HR) 2.17, 95% confidence interval (95% CI) 1.82-2.58, p < 0.0001]; longer for patients with SpA (HR 1.60, 95% CI 1.20-2.13, p = 0.001); and longer without concomitant DMARD (HR 0.70, 95% CI 0.51-0.97, p = 0.03).
Our results indicate a lower retention rate of TNF blockers in daily practice compared with clinical trials, with no difference between the 3 currently available agents. Moreover, results suggest greater benefit in SpA. The role of concomitant DMARD remains to be confirmed.