Efficacy and safety of off-label use of rituximab in refractory lupus: data from the Italian Multicentre Registry

Objective: To evaluate the efficacy and safety of rituximab (RTX) in patients with systemic lupus erythematosus (SLE) refractory to standard therapy in the clinical practice setting. Methods: 145 SLE patients (ACR criteria) were treated with RTX in 11 Italian Centres: 118 with two infusions (1 g), two weeks apart; 27 with 4 infusions (375 mg/m2), one week apart, followed in 10 cases by two further doses, after 1 and 2 months. Systemic complete response (CR) was defined as European Consensus Lupus Activity Measurement (ECLAM) score ≤1 and partial response (PR) as 1< ECLAM ≤3. Renal CR (RCR) and renal PR (RPR) were defined according to EULAR recommendations for management of lupus nephritis. Results Data from 134 (92.4%) patients were available. The mean±SD follow-up was 27.3±18.5 months. After the first course of RTX, CR or PR were observed in 85.8% and CR in 45.5% of cases; RCR or RPR in 94.1% and RCR in 30.9% of patients after 12-month follow-up. Disease flares occurred in 35.1% and renal flares in 31.2% of patients during observational period. Among patients retreated, CR or PR were observed in 84.4% and CR in 57.8% of cases. Adverse events, infections, and infusion reactions occurred after first RTX course in 23.8%, 16.4%, and 3.8% of patients and after retreatment in 33.3%, 22.2% and 11.1%, respectively. No severe infusion reactions or deaths occurred. Conclusion Data from Italian multicentre RTX Registry confirmed the efficacy and safety of RTX in SLE patients refractory to standard treatment in clinical practice setting.