Cases from the Immune‐Related Adverse Event Tumor Board: Diagnosis and Management of Immune Checkpoint Blockade‐Induced Diabetes

The addition of immune checkpoint inhibitors to the armamentarium of cancer therapies has resulted in unprecedented improvement in clinical outcomes for a vast range of malignancies. Because they interfere with the physiologic function of immune checkpoints, such as programmed cell death protein 1 or cytotoxic T‐lymphocyte‐associated protein 4, to promote self‐tolerance, these agents are associated with a unique spectrum of immune‐related adverse events (irAEs). Immune‐mediated endocrinopathies are among the most commonly noted irAEs. Immune‐mediated diabetes is an uncommon irAE but can be associated with significant morbidity if it is not recognized and treated in a time‐sensitive manner. In this manuscript, we present a case based discussion and review of the literature pertaining to immune‐mediated diabetes associated with immune checkpoint blockade. Key Points Immune checkpoint inhibitor associated diabetes mellitus often resembles type 1 diabetes mellitus (DM) in its pathophysiology and clinical manifestations. However, some patients may present with type 2 DM or worsening hyperglycemia in the setting of pre‐existent DM. Early recognition and management is key to preventing life‐threatening events such as diabetic ketoacidosis. Endocrinology referral and interdisciplinary management should be considered for every patient to optimize glycemic control and to ensure optimal monitoring for long‐term microvascular complications.