Pembrolizumab-Induced Autoimmune Grade 4 Neutropenia in a Patient With Advanced Bladder Cancer: A Case Report

Neutropenia is amongst the rare, but potentially life-threatening complications of immune checkpoint inhibitors (ICI). Awareness about this dangerous toxicity and its adequate treatment since early detection is of utmost importance. Unfortunately, there are no therapeutical guidelines to deal with neutropenia specifically. The best alternative is informed extrapolations based on reported neutropenia cases and established guidelines for other immune-related adverse events. We report a case of pembrolizumab-related grade 4 neutropenia in a patient with metastatic bladder cancer. She was successfully treated with immunosuppressive and supportive measures. Further studies are required to understand the range of immune-related adverse events and to improve their management.