Randomized Clinical Trial to Compare Efficacy and Safety of Repeated Courses of Rituximab to That of Maintenance Mycophenolate Mofetil Following Single Course of Rituximab in Maintaining Remission Over 24 Months Among Children With Steroid Dependent Nephrotic Syndrome

The vast majority of children with idiopathic nephrotic syndrome respond well to corticosteroid treatment. However, as many as 70% experience at least one relapse, and 30% develop a more complicated course with frequent relapses (FRNS) with or without steroid dependency (SDNS). Extended steroid exposure in these children often results in long-term complications. The management of patients with SDNS is challenging and expensive. Relapses may lead to serious complications, e.g. related to anasarca, hypertension, life threatening infections (peritonitis, pneumonia, meningitis), thrombosis and malnutrition. Repeated courses or even continuous steroid treatment lead to considerable medication related toxicity and morbidity.

The goal of treatment is to reduce the rate of relapses, the cumulative dose of corticosteroids, and the incidence of serious complications. Various prospective studies suggest that Rituximab, a B cell depleting monoclonal antibody, could be a safe and effective alternative to steroid or immunosuppressants to achieve and maintain remission in this population. Single rituximab infusion have been shown to be efficacious for 6 to 12 months and the side effect profile observed to date is very benign but after 6-8 months there was relapse due to regeneration of B-lymphocytes, hence for maintenance of remission MMF has been considered. In spite of good initial response, rituximab responders always remain prone to further relapse with regeneration of B lymphocytes, necessitating either repeat course of rituximab or addition of another steroid-sparing immunosuppressant. Reports suggest efficacy of rituximab may vary depending on disease pathology, clinical course, and simultaneous use of other immunosuppressants.

The aim of the RITURNS II study is to evaluate the efficacy and safety of Repeat courses of Rituximab to that of maintenance Mycophenolate Mofetil following single course of Rituximab in maintaining remission over 24 months among Children with Steroid Dependent Nephrotic Syndrome (SDNS).