Successful Switch to Obinutuzumab in a Rituximab-Intolerant Child with Difficult-to-Treat Idiopathic Nephrotic Syndrome.

: Idiopathic nephrotic syndrome (INS) is the most common cause of nephrotic syndrome in children. A hallmark of the disease is the rapid remission of proteinuria following a high dose of steroids. Recurrent disease or steroid dependence are common, leading to a high steroid burden and the introduction of steroid sparing therapy. Anti-CD20 antibodies have been increasingly used with excellent results in complicated INS. Nevertheless, their use can be limited by the occurrence of infusion-related reactions (IRRs). : This report discusses further treatment options for children who are intolerant to RTX and presents the first report of a successful switch to obinutuzumab (OBI) for a child with difficult-to-treat steroid-dependent nephrotic syndrome (SDNS) and RTX intolerance who was unresponsive to a desensitization protocol. : A 12-year-old boy with SDNS since the age of 2, was treated with steroids, cyclophosphamide and cyclosporine A (CsA). Because of the prolonged use of calcineurin inhibitors, a course of rituximab (RTX) was planned. Unfortunately, during first infusion, the boy presented with IRR. A desensitization protocol following the first unsuccessful infusion also failed. Facing the risks of long-term cyclosporine therapy, a decision was made to switch to another type of anti-CD20 antibody. Obinutuzumab infusion with a modified premedication scheme was uneventful. : Switching therapy to obinutuzumab may be considered an option in nephrotic children who are intolerant to RTX when alternative therapies have been exhausted. The addition of montelukast to premedication and employment of desensitization protocols may decrease the risk of infusion-related reactions to anti-CD20 agents.