Immune Checkpoint Inhibitor-Induced Myocarditis With Concurrent Myasthenia Gravis

Immune checkpoint inhibitors (ICIs) revolutionized cancer treatment because they have shown curative responses for patients with metastatic melanoma, non-small cell lung cancer, head and neck, and renal cancers. These therapies work via T-cell activation by targeting molecules such as the cytotoxic T lymphocyte antigen-4 or programmed death-1 receptors. However, despite their demonstrated efficacy, one needs to be cognizant of life-threatening immune-related adverse events (irAEs). Herein, we report on a patient with metastatic renal cell carcinoma that was treated with nivolumab, who developed concurrent myocarditis and myasthenia gravis (MG) managed with abatacept because of poor clinical improvement with glucocorticoids, infliximab, and mycophenolate.