Subcutaneous ofatumumab in recurrent focal segmental glomerulosclerosis after kidney transplantation.

Background: Recurrent focal segmental glomerulosclerosis (rFSGS) is a severe condition occurring after kidney transplantation (KT) and has a high graft loss rate. Its incidence is reported as up to 55% of KTs, typically diagnosed within 1.5 months post-transplant. Treatment typically involves plasmapheresis, with adjunctive rituximab therapy, achieving partial or complete remission in up to 57% of patients. We report the case of a paediatric patient who experienced two episodes of rFSGS post-KT, presenting with acute kidney injury (AKI). The second episode was treated with subcutaneous ofatumumab with complete remission.

Methods: The treatment protocol included four weekly plasmapheresis treatments, with Kesimpta administered subcutaneously at a dose of 20 mg twice weekly, given at the end of the plasmapheresis session. Plasmapheresis was then discontinued for 48-72 h following Kesimpta administration. CD20 levels were followed.

Results: A KT patient experienced a second rFSGS, presenting with massive proteinuria of 13 g/day, 3 years post-transplant. Due to severe allergic reaction to rituximab during the first recurrence, she was treated with a combination of plasmapheresis and Kesimpta during the second episode. CD20 levels were undetected within two doses of Kesimpta treatment. Full remission and AKI resolved 1 month after initiation of this treatment. There were no severe adverse effects of the combined protocol.

Conclusions: We propose a combination treatment of subcutaneous ofatumumab and intensive plasmapheresis, with CD19 and CD20 levels monitored regularly, might be safe and effective in rFSGS in KT patients.