The vast majority of children with idiopathic nephrotic syndrome respond well to corticosteroid treatment. However, as many as 20% experience a more complicated course with steroid resistance (SRNS). Repeated and prolonged courses of steroids in these children often result in long-term complications. The goal of treatment is to reduce the rate of relapses, the cumulative dose of corticosteroids, and the incidence of serious complications. In order to minimize the side effects of steroid therapy, different steroid sparing agents such as cyclophosphamide, calcineurin inhibitors(CNI), levamisole, and mycophenolate mofetil (MMF) have been used in SRNS. Whereas CNI are usually considered the steroid sparing drug class of first choice, rituximab is increasingly used as alternative to minimize CNI toxicity. 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. Rituximab infusion have been shown to be efficacious for 6 to 12 months and the side effect profile observed to date is very benign. Studies comparing the usefulness of these agents are lacking. In this proposed randomized controlled trial, the investigators want to compare the efficacy and safety of CNI to that of Rituximab in treating children with SRNS.

Inclusion Criteria:

• Children between 3 and 16 years with SRNS
• Minimal Change disease/Messengioproliferative glomerulonephritis/Focal segmental glomerulosclerosis as per Kidney Biopsy report.
• Estimated glomerular filtration rate (eGFR) >80 ml/min per 1.73 m2 at study entry.
• Not received any steroid sparing agent previously.
• Parents willing to give informed written consent.
• Ability to swallow tablet

Exclusion Criteria:

• Known etiology (e.g., lupus erythematosus, IgA nephropathy, amyloidosis, malignancy, other secondary forms of NS)
• Patients with severe leucopenia (leucocytes <3.0× 1000 cells/mm3), severe anemia (haemoglobin <8.9 g/dl), thrombocytopenia (platelet <100.0 × 1000 cells/mm3) or deranged liver function tests (AST or ALT to >50 IU/L ) at enrolment.
• Known active chronic infection (tuberculosis, HIV, hepatitis B or C)
• Live vaccination within 1 mo