Objective: The aim of this study was to compare the efficacy and safety of rituximab (RTX) as a function of patient age.
Methods: We included all rheumatoid arthritis patients in the AutoImmunity and Rituximab registry with a 2-year followup.
Results: Of the 1,709 patients, 191 were age ≥75 years, 417 were ages 65–74 years, 907 were ages 50–64 years, and 194 were age <50 years. At baseline, the elderly and very elderly patients presented with longer disease duration, a higher incidence of erythrocyte sedimentation rate and C-reactive protein level, a lower incidence of previous tumor necrosis factor α (TNFα) therapy, and a smaller number of previously used TNFα agents. Disease activity, rheumatoid factor (RF), or anti–cyclic citrullinated peptide (anti-CCP) antibodies and corticosteroid therapy were not statistically different among the groups. At 24 months, no significant difference was shown among the groups for RTX discontinuation rates (36.1% if age <50 years, 32.6% if ages 50–64 years, 34.5% if ages 65–74 years, and 32.5% if age >75 years). The reasons for discontinuation (inefficacy, adverse events) were the same in all 4 groups. Infections were more common in the elderly. Patients ages 65–75 years were more likely to be good responders than nonresponders at 1 year of followup than patients age ≥75 years (odds ratio 3.81, 95% confidence interval 1.14–12.79) after adjustment on disease duration, RF/anti-CCP positivity, corticosteroids, anti-TNF use, and baseline Disease Activity Score in 28 joints (DAS28). After the sixth month, the decrease in DAS28 score was less marked in the population age >75 years than in the group age <50 years.
Conclusion: The efficacy and safety of RTX is affected by age.