Long-Term Prognosis of Adult Patients with Steroid-Dependent Minimal Change Nephrotic Syndrome Following Rituximab Treatment

This study was to evaluate the long-term efficacy and safety of a single-dose rituximab regimen rituximab treatment in adult patients with steroid-dependent minimal change nephrotic syndrome (MCNS). We conducted a prospective cohort study with historical controls to evaluate the effect of single-dose infusions of rituximab at 375 mg/m(2) BSA per dose administered at intervals of 6 months for a period of 24 months. At the end of the 24-month period, the patients were divided into the treatment continuation (n = 20) and treatment discontinuation (n = 5) groups according to their intention to continue/discontinue the treatment. A significant reduction in the total number of relapses was observed during the 24-month period after the first rituximab infusion as compared with that during the 24-month period before the first rituximab infusion (108 vs. 8, P < 0.001). Complete remission was induced/maintained in all patients from 12 to 24 months after the first rituximab infusion. In regard to the clinical course after 24 months, 4 of the 20 patients in the treatment continuation group discontinued the rituximab treatment after the fifth infusion and 2 patients discontinued the treatment after the sixth infusion. However, complete remission was maintained in all the 20 patients of this group during the 12-month observation period after the first four single-dose rituximab infusions. On the other hand, 1 of the 5 patients in the treatment discontinuation group developed relapse during the observation period after the first four rituximab infusions, and the rituximab treatment was resumed. In our trial, rituximab therapy was associated with maintenance of complete remission. Complete remission was maintained even in most of the patients who showed B-cell repletion after discontinuation of rituximab therapy. Thus, rituximab may be considered as a radical therapeutic agent for patients with steroid-dependent MCNS.