Efficacy and safety of long-term repeated use of rituximab in pediatric patients with nephrotic syndrome

Abstract

Background We aimed to investigate the efficacy and safety of long-term repeated use of Rituximab (RTX) in pediatric patients with nephrotic syndrome (NS). Methods Retrospective review of medical records for 50 patients with steroid-dependent NS (SDNS) who had received more than three cycles of RTX was conducted; each consisted of one to four infusions of RTX until B lymphocytes were depleted. Results The median age of starting the first RTX cycle was 12.4 years (interquartile ranges (IQR) 10.2–14.6). During a median follow-up period of 6.3 (IQR 3.6–8.6) years, patients received a median of 5.0 RTX cycles (IQR 4.0–7.3). The number of relapses decreased from a median of 2.0 relapses per year (IQR 1.0–3.0) to 0.2 relapses per year (IQR 0.0–0.5) after long-term RTX treatments (P < 0.001). Longer relapse-free periods were associated with more than four RTX cycles, longer B cell depletion, older age at each RTX treatment, and lower cholesterol levels. B lymphocytes recovered to 1% at a median of 5.9 months (95% confidence interval (CI) 5.7–6.1) after RTX administration. Factors related to a longer period of B-cell depletion included more than five RTX cycles, a higher dose of RTX, older age at treatment, and concurrent use of antimetabolites. During repeated RTX treatments, 11%, 6%, and 2% of patients developed hypogammaglobulinemia, severe infection, and severe neutropenia, respectively. Conclusions Long-term repeated use of RTX was effective and safe in pediatric NS patients. Furthermore, the redosing of RTX could be chosen by considering predictive factors for relapse-free and B-cell depletion periods.