This study focuses on individuals with Idiopathic Nephrotic Syndrome, a rare condition where the kidneys leak too much protein into the urine, which can cause swelling in the body. The research specifically looks at patients whose condition frequently returns and who have previously relied on rituximab. The purpose of the study is to evaluate if the drug obinutuzumab can help keep the disease in remission, meaning a period where the symptoms are controlled, for at least 12 months.

Participants will receive obinutuzumab through an infusion, which is a method of delivering medication directly into a vein. This treatment is administered once the patient reaches remission using steroid therapy. During the course of the study, health changes will be monitored, including levels of protein and albumin in the blood and urine, as well as kidney function through iohexol plasma clearance, a technique used to measure how well the kidneys filter the blood.