Efficacy and safety of two dose regimens of rituximab for idiopathic membranous nephropathy

Objective To compare the clinical efficacy and safety of two regimens of rituximab (RTX) for idiopathic membranous nephropathy (IMN).

Methods A total of 79 IMN patients were recruited from December 01, 2019 to December 31, 2021. RTX two-dose regimen group (n=49): two infusions of 1g at 2-week intervals; if nephrotic albuminuria persisted during a 6-month follow-up, the regimen could be repeated once. RTX four-dose regimen group (n=30): four infusions of 375 mg/m² at 1-week intervals. Both groups had a combination of low-dose glucocorticoid. The differences of 24-hour urinary protein, serum albumin, blood creatinine, peripheral blood CD19⁺ cell count, anti-PLA2R antibody titer, disease remission rate and adverse reactions were compared between two groups before and at different timepoints post-treatment.

Results No significant inter-group differences existed in gender, age, body mass index, blood pressure, 24-hour urinary protein, serum albumin, blood creatinine, eGFR, anti-PLA2R antibody or peripheral blood CD19⁺ cell count pre-treatment (P>0.05). At Month 12, 24-hour urinary protein declined markedly in 2 groups as compared with pre-treatment (P<0.01); serum level of albumin spiked markedly as compared with pre-treatment (P<0.01). However, no significant inter-group difference existed in reduction of urinary protein and recovery of serum albumin post-treatment (P>0.05). In terms of serum creatinine, total renal function of 2 groups remained stable without statistical significance (P>0.05). Anti-PLA2R-Ab level declined markedly in two groups post-treatment as compared with pre-treatment and the difference was not statistically significant (P>0.05). In terms of disease remission, total effective rate reached 75.95% at Month 12 and clinical remission rate of RTX two-dose regimen group was significantly higher than that of RTX four-dose regimen group (85.71% vs 60%). And the difference was statistically significant (P<0.01). Meanwhile, recurrence rate was lower in RTX two-dose group than that in RTX four-dose group (18.37% vs 23.33%). No significant inter-group difference existed in adverse reactions (P>0.05).

Conclusion With a higher clinical remission rate without a higher incidence of adverse reactions, high-dose RTX regimen is more suitable for treating IMN. However, adverse reactions causing severe hypokalemia deserve greater attention.