Optimized rituximab regimen versus recommended regimen for idiopathic membranous nephropathy: A single-center retrospective cohort study

Background: Rituximab (RTX) has become the first -line treatment for idiopathic membranous nephropathy (IMN). Compared with conventional therapy, rituximab therapy has a more favorable safety profile. However, the recommended RTX dose as a flux may have its limitations. The aim of this study was to investigate the clinical efficacy and safety of three regimens, including a cyclic corticosteroid-cyclophosphamide regimen and two different doses of RTX regimens, for the treatment of IMN. Methods: We recruited 58 patients with IMN confirmed by renal biopsy. 20 patients were treated with a cycle regimen, 22 patients were received RTX with 500 mg per week, totaling a dose of 2000 mg (optimized RTX group), and 16 patients received RTX with 1000 mg at day 1 and day 15 (recommended RTX group). Treatment responses, including complete remission (CR) and partial remission (PR), and outcome adverse events such as steroid diabetes, infections and a drop in white blood cell count, were compared among the three groups after 9 months of follow-up. Results: At 9-month follow-up, the composite remission rates (CR + PR) were 90 %, 72.7 %, and 75 % for the cycle regimen group, optimized RTX group, and recommended RTX group, respectively, with CR of 35 %, 22.7 %, and 25 %, respectively. There was no statistical difference between the three groups on CR and composite remission. Kaplan-Meier survival analyses showed no significant differences in cumulative CR rates and cumulative composite remission rates among the three groups (P = 0.632, P = 0.258). The cycle regimen group had a higher risk of steroid diabetes (35 %). Compared with the recommended RTX regimen, the optimized regimen reduced the incidence of adverse events of infection (9.1 % vs. 37.5 %, P = 0.049), especially in patients older than 60 years of age (P = 0.026). A lower anti-PLA2R at baseline may be associated with a higher risk of infection (P = 0.043). Conclusions: The efficiency of low-dose and long-course of RTX regiment is not inferior to the recommended treatment regimen, and this regimen can effectively reduce the incidence of infection in patients with IMN. Moreover, we recommend a low-dose, long course of RTX treatment for the elderly.