Rituximab: is replacement of cyclophosphamide and calcineurin inhibitors in steroid-dependent nephrotic syndrome possible?

The anti-CD20 antibody rituximab has been used successfully as a rescue therapy in some patients with therapy-refractory steroid-dependent nephrotic syndrome (SDNS), including both primary SDNS with minimal changes on biopsy and recurrent focal segmental glomerulosclerosis (FSGS) after renal transplantation. All patients showed remission from steroid dependency for at least 9 months concurring with the reappearance of B lymphocytes that had been eliminated by rituximab. The doses used so far vary between 375 mg/m2 per dose at weekly intervals for 6 weeks and a single dose of 375 mg/m2. Until now, with the limited information available, no substantial adverse effects have been reported. However, a recommendation to use rituximab instead of any other established treatment, such as cyclophosphamide, in SDNS cannot be given before clinical studies have been conducted, especially as publication bias cannot be excluded.