Rituximab as add-on therapy in patients with resistant lupus nephritis who have failed induction or maintenance therapy with other agents: A real-world experience from a single center in Mumbai.

Background: Lupus nephritis (LN) is associated with poor outcomes and a significant risk of progression to end-stage renal disease (ESRD). Some patients with resistant LN do not respond adequately to current treatment options and need alternative strategies or therapies.

Objective: The objective is to evaluate the efficacy and safety of rituximab as a re-induction therapy (Re-RTX) followed by maintenance therapy for patients with resistant LN.

Methods: Twenty-four patients with resistant LN (failed initial induction therapy or severe relapse after remission) were analyzed. Re-RTX was co-administered with other immunosuppressants. The primary KDIGO criteria outcomes included renal response (complete and partial), disease progression, relapses, and infections.

Results: The median age was 28 years (IQR 24.5-42), and the female-to-male ratio was 11:1. All patients had active LN, and 91.3% had proliferative LN. Baseline creatinine was 1.075 mg% (IQR 0.7-1.38), and mean urine protein-to-creatinine ratio (UPCR) was 4.9 (IQR 2.8-6.65). Of the patients receiving RTX as re-induction therapy, 66.6% (16/24) had failed initial induction therapy with other immunosuppressants, whereas 33.3% (8/24) had severe relapse during maintenance therapy.Re-RTX had a favorable renal response at 6 months, with 91.7% of the patients responding (20.8% complete response and 70.8% partial response). At 12 months, 58.3% of the patients maintained a renal response (25% complete response and 33.3% partial response). Approximately one-third of patients relapsed within a year.Fourteen patients (58.3%) continued RTX maintenance therapy with two different treatment regimens. At 6 months, Regimen-1 (500 mg every 6 months) resulted in a partial response in 43% (3/7) and relapse in 57% (4/7) of patients. Regimen 2 (1 g dose per year) achieved a complete response in 28.5% (2/7) and a partial response in 71.5% (5/7) with no relapses at 6 months.At a median follow-up of 29 months, adverse renal outcomes were observed in 29.16% of the patients with progression to advanced chronic kidney disease (CKD) or end-stage renal disease (ESRD). The overall use of Re-RTX was considered safe, with a reported infection prevalence of 16%, which is comparable to the existing data.

Conclusion: Re-RTX demonstrated efficacy and safety as an induction therapy for resistant LN. However, the response waned after 1 year, underscoring the need for optimized maintenance therapy.