Diabetic Ketoacidosis as an Immune-related Adverse Event from Pembrolizumab in Non-Small Cell Lung Cancer.

Programmed cell death protein 1 pathway inhibitors are now routinely administered to patients with non-small cell lung cancer, and prompt recognition of immune-related adverse events is critical to managing serious drug toxicities. Here, we describe a 66-year-old man with no known history of diabetes who presented with diabetic ketoacidosis after receiving 3 doses of pembrolizumab for lung adenocarcinoma. Autoimmune diabetes is a rare but potentially life-threatening complication of programmed cell death protein 1 inhibitors.