Long-Term Efficacy and Safety of Repeated Rituximab to Maintain Remission in Idiopathic Childhood Nephrotic Syndrome: An International Study.

BACKGROUND: Long-term outcomes after multiple courses of rituximab among children with frequently relapsing, steroid-dependent nephrotic syndrome (FRSDNS) are unknown. METHODS: A retrospective cohort study at 16 pediatric nephrology centers from ten countries in Asia, Europe, and North America included children with FRSDNS who received two or more courses of rituximab. Primary outcomes were relapse-free survival and adverse events. RESULTS: A total of 346 children (age, 9.8 years; IQR, 6.6-13.5 years; 73% boys) received 1149 courses of rituximab. A total of 145, 83, 50, 28, 22, and 18 children received two, three, four, five, six, and seven or more courses, respectively. Median (IQR) follow-up was 5.9 (4.3-7.7) years. Relapse-free survival differed by treatment courses (clustered log-rank test P<0.001). Compared with the first course (10.0 months; 95% CI, 9.0 to 10.7 months), relapse-free period and relapse risk progressively improved after subsequent courses (12.0-16.0 months; HRadj, 0.03-0.13; 95% CI, 0.01 to 0.18; P<0.001). The duration of B-cell depletion remained similar with repeated treatments (6.1 months; 95% CI, 6.0 to 6.3 months). Adverse events were mostly mild; the most common adverse events were hypogammaglobulinemia (50.9%), infection (4.5%), and neutropenia (3.7%). Side effects did not increase with more treatment courses nor a higher cumulative dose. Only 78 of the 353 episodes of hypogammaglobulinemia were clinically significant. Younger age at presentation (2.8 versus 3.3 years; P=0.05), age at first rituximab treatment (8.0 versus 10.0 years; P=0.01), and history of steroid resistance (28% versus 18%; P=0.01) were associated with significant hypogammaglobulinemia. All 53 infective episodes resolved, except for one patient with hepatitis B infection and another with EBV infection. There were 42 episodes of neutropenia, associated with history of steroid resistance (30% versus 20%; P=0.04). Upon last follow-up, 332 children (96%) had normal kidney function. CONCLUSIONS: Children receiving repeated courses of rituximab for FRSDNS experience an improving clinical response. Side effects appear acceptable, but significant complications can occur. These findings support repeated rituximab use in FRSDNS.

Rituximab in childhood steroid-sensitive nephrotic syndrome: are multiple subsequent courses safe and effective?

INTRODUCTION: Idiopathic nephrotic syndrome is the most common glomerular disease in children. The majority of patients respond well to steroids. However, the relapse rate is high and many develop steroid dependency. Although other immunosuppressive medicines are successfully used as steroid-sparing agents, some children still have frequent relapsing episodes. Rituximab (RTX), a chimeric anti-CD20 monoclonal antibody, has shown to be effective in treating difficult frequently relapsing/steroid-dependent nephrotic syndrome (FR/SDNS). Data on the effectiveness and long-term treatment outcomes of repeated courses of RTX are, however, scarce. MATERIAL AND METHODS: Children and young people with FR/SDNS, aged 1-18 years, who received RTX at Great Ormond Street Hospital (GOSH) from 2006 to 2018 were reviewed. RESULTS: During these 12 years, 103 children with FR/SDNS received RTX infusions at GOSH. Among these, 58 cases needed repeated courses of RTX: 2, 3, 4, 5, 6 and 7 repeated courses were given to 21, 21, 7, 5, 1 and 3 patients, respectively. The overall median time to relapse post-RTX was 11 months (range 1-53 months). There was no change in relapse-free interval with subsequent courses of RTX. No difference was found between age groups, genders and ethnicities. No severe side effects were noted. CONCLUSIONS: RTX seems to be safe even after several repeated courses. However, long-term follow-up and further studies are needed, with a focus on side-effects in particular.