Mycophenolate as Primary Treatment for Immune Checkpoint Inhibitor Induced Acute Kidney Injury in a Patient with Concurrent Immunotherapy-Associated Diabetes: A Case Report.

Immune checkpoint inhibitors enhance T cell response against malignant cells and are standard of care in many tumor types. Disinhibition of cytotoxic T cells in normal organs and inhibition of regulatory T cells can lead to immune-related adverse events. Here we describe a 60-year-old man with metastatic melanoma treated with three cycles of nivolumab and ipilimumab. He subsequently presented with new-onset brittle diabetes, rash, fever, and acute kidney injury. After initiation of insulin and aggressive fluid resuscitation, his kidney functions transiently improved but then dramatically worsened. Due concerns regarding hyperglycemia, a steroid-sparing agent was necessary and he was successfully treated with front-line mycophenolate mofetil, leading to normalization of renal function. The patient went on to develop a complete response and remains disease-free four years later. We conclude that mycophenolate can serve as an effective frontline therapy for immune-mediated acute kidney injury when steroids are contraindicated.