Although there is strong evidence supporting the short-term efficacy and safety 
of anti-tumour necrosis factor-alpha agents, few studies have examined the 
long-term effects. We evaluated 511 patients with long-standing refractory 
rheumatoid arthritis treated with intravenous infusions of infliximab 3 mg/kg at 
weeks 0, 2, 6, and 14 and every 8 weeks thereafter for 4 years. Among the 
initial 511 patients included in the study, 479 could be evaluated; of these, 
295 (61.6%) were still receiving infliximab treatment at year 4 of follow-up. 
The most common reasons for treatment discontinuation were lack of efficacy (65 
patients, 13.6%), safety (81 patients, 16.9%), and elective change (38 patients, 
7.9%). Analysis of disease activity scores (DAS28 [disease activity score based 
on the 28-joint count]) over time showed that, after the initial rapid 
improvement during the first 6 to 22 weeks of therapy, a further decrease in 
disease activity of 0.2 units in the DAS28 score per year was observed. DAS28 
scores, measured at week 14 or 22, were found to predict subsequent 
discontinuation due to lack of efficacy. In conclusion, long-term maintenance 
therapy with infliximab 3 mg/kg is effective in producing further reductions in 
disease activity. Disease activity measured by the DAS28 at week 14 or 22 of 
infliximab therapy was the best predictor of long-term attrition.