Comparison of Six-Month Efficacy and Safety of Rituximab in Elderly and Younger Patients With Rheumatoid Arthritis: A Prospective Real-World Study.

Introduction The efficacy and safety of biologic disease-modifying antirheumatic drugs, particularly tumor necrosis factor (TNF) inhibitors (anti-TNF agents), are well established in rheumatoid arthritis (RA). However, treating older patients remains challenging because of the higher burden of comorbidities, polypharmacy, and increased susceptibility to treatment-emergent adverse events (TEAEs). Rituximab (RTX), a monoclonal antibody targeting CD20-positive B cells, is widely used in our setting as a first-line biologic therapy in patients with severe disease and/or contraindications to anti-TNF agents. Nevertheless, data regarding its efficacy and safety in elderly patients remain scarce. The primary objective of this study was to compare the six-month efficacy of RTX between elderly (≥65 years) and younger (<65 years) patients with RA. Secondary objectives were to compare remission rates, low disease activity (LDA), functional outcomes, inflammatory markers, and safety between the two age groups. Methods This prospective real-world study included patients with RA treated with RTX, regardless of the number of previous treatment courses. The study population was stratified into an elderly group (≥65 years, Group A, n = 23) and a younger group (<65 years, Group B, n = 73). Patients underwent clinical and laboratory assessments at baseline and at four and six months following the RTX treatment cycle included in the study. Therapeutic response was determined using changes in the Disease Activity Score in 28 joints calculated with CRP (DAS28-CRP), as well as remission and LDA rates. The primary outcome was the change in DAS28-CRP from baseline to month 6. Safety was assessed by recording TEAEs, including infections, serious TEAEs, and treatment discontinuation. Results A total of 96 patients were included: 23 elderly patients (mean age 69.4 ± 2.8 years; 78.3% female) and 73 younger patients (mean age 53.2 ± 7.1 years; 89.0% female). Baseline demographic and disease characteristics were generally comparable between groups. Significant improvement in disease activity was observed in both groups at four and six months. At six months, the mean improvement in DAS28-CRP was -2.17 (95% CI: -2.82 to -1.41) in elderly patients and -2.27 (95% CI: -2.59 to -1.75) in younger patients (p = 0.90). Remission rates were similar between elderly and younger patients (11/23 (47.8%) vs. 31/73 (42.5%), p = 0.81). TEAEs were uncommon in both groups and consisted mainly of mild infections, with no treatment-related deaths reported. Conclusions This prospective real-world study suggests that RTX was associated with similar short-term efficacy outcomes and a low incidence of TEAEs in elderly and younger patients with RA. In this study, advanced age was not associated with a poorer therapeutic response to RTX. These findings provide reassuring short-term real-world evidence supporting the use of RTX in older adults with RA within an individualized treatment strategy. Larger multicenter studies are warranted to confirm these findings.