Efficacy and safety of rituximab second-line therapy for membranous nephropathy: A prospective, matched-cohort study

Background/Aims: First-line immunosuppression with the B-cell depleting antibody rituximab reduced proteinuria and induced remission of the disease in patients with nephrotic syndrome (NS) secondary to idiopathic membranous nephropathy (IMN). Here we evaluated whether rituximab is equally effective in patients who failed to respond to previous immunosuppressive treatment. Methods: This academic, matched-cohort study, compared 2-year outcomes of 11 consecutive IMN patients who received second-line rituximab therapy for NS persisting or relapsing after previous treatment with steroids alone or combined with alkylating agents, cyclosporine, or immunoglobulin G, with those of 11 age- (±5 years), gender- and proteinuria- (±1 g/24h) matched reference patients given first-line rituximab therapy. Results: Patients' and reference patients' baseline characteristics were similar. Compared to baseline, 24-hour proteinuria similarly declined at 1 and 2 years post-rituximab (by 50.5 ± 25.1% and 60.9 ± 17.4% in patients and by 52.7 ± 31.5% and 69.4 ± 40.4% in reference patients, respectively; p < 0.01 for all comparisons vs. baseline). 8 patients and 7 reference patients achieved full (3 vs. 2) or partial (5 per cohort) proteinuria remission. Hypoalbuminemia and hyperlipidemia normalized in both groups. Self-limited infusion-related reactions occurred in 1 subject per cohort. Conclusion: Rituximab reduced proteinuria in IMN patients with no or only transientresponse to unselective immunosuppression as effectively and safely as in patients without previous immunosuppression.