Ofatumumab for the treatment of childhood nephrotic syndrome

Background Ofatumumab is a humanized anti-CD20 monoclonal antibody that has recently garnered interest as a potential therapeutic agent for nephrotic syndrome. We report our center’s experience in administering ofatumumab to five pediatric patients with idiopathic nephrotic syndrome. Methods Between March 2015 and November 2016, five patients were treated with ofatumumab. One patient had post-transplant recurrent focal segmental glomerulosclerosis (FSGS) which had been resistant to plasmapheresis and numerous immunosuppressive agents. Four patients had nephrotic syndrome in their native kidneys, one with initial steroid-resistant disease and the others with subsequent development of steroid resistance. Two of the patients were treated with a desensitization protocol after experiencing hypersensitivity reactions to ofatumumab. Results One patient did not complete ofatumumab treatment due to infusion reactions. Of the four remaining patients, three achieved complete remission after treatment, and one achieved partial remission. One of the patients achieving complete remission represents the first reported case of successful treatment of post-transplant recurrent FSGS using ofatumumab. Two patients who received ofatumumab with our desensitization protocol were able to complete their treatments after initially experiencing hypersensitivity reactions. Conclusions Ofatumumab may be an effective treatment for refractory childhood nephrotic syndrome and post-transplant recurrent FSGS. A desensitization protocol may be helpful to address hypersensitivity reactions.