Safety Profile of Repeated Rituximab Cycles in Unselected Rheumatoid Arthritis Patients: a Long-term, Prospective Real-life Study

Objectives: To evaluate the long-term safety of rituximab (RTX) in rheumatoid arthritis (RA) patients in daily clinical practice.

Methods: This was a multicentre (17 Greek Rheumatology sites), prospective, long-term, pharmacovigilance study of patients with moderate to severe RA and an inadequate response or intolerance to ≥1 anti-tumour necrosis factor (TNF) agents. Adverse events (AEs) were recorded and collected prospectively every 2-6 months.

Results: 234 patients (mean age: 59±12.5, 79.5% women, mean DAS28: 5.35±1.32) were included and followed for 27.7 months (median). The overall AEs, serious AE (SAEs) and serious infection (SIEs) rate were 48.36, 6.68 and 2.53/100 patient-years, respectively. Three cases of hepatitis B virus (HBV) reactivation were recorded (two in chronic and one in past HBV infection). Withdrawals due to AEs (5.6%) occurred more frequently during the first cycles of RTX therapy while repeated RTX cycles were not associated with an increased risk of AEs. There were 3 deaths with an incidence rate of 0.69/100 patient-years. Age ≥65 years was associated with a higher incidence rate ratio of AEs and SAEs as compared to <65 years (1.53, p=0.002 and 2.88, p=0.005, respectively). Drug retention rate during 434.28 patient-years of follow-up was 57.3%. Factors associated with drug discontinuation by multivariate analysis included age, baseline swollen joint count and no use of concomitant methotrexate therapy.

Conclusions: Long-term RTX therapy in a real-life RA cohort, did not reveal any new safety issues. Advanced age was associated with increased risk of AEs and premature drug discontinuation.