Immune checkpoint inhibitors (ICIs) have expanded therapeutic options across multiple malignancies, yet immune-related endocrine complications remain clinically significant. A retrospective cohort analysis published in Diabetic Medicine evaluated checkpoint inhibitor-associated autoimmune diabetes mellitus (CIADM) among 4382 hospitalized patients receiving anti-programmed cell death-1 (PD-1) or anti-programmed death ligand-1 (PD-L1) inhibitors between 2020 and 2024. The analysis aimed to define the clinical spectrum, timing, and causality of this rare adverse event.

Seven cases of CIADM were identified, corresponding to an incidence of 0.16%. Median age at presentation was 52 years, and most cases occurred in males. Hepatocellular carcinoma represented the most frequent underlying malignancy. CIADM developed after a median of 8 treatment cycles. At presentation, 86% of patients had diabetic ketoacidosis (DKA), indicating acute metabolic decompensation. All cases demonstrated severe pancreatic β-cell dysfunction with undetectable fasting and postprandial C-peptide levels. Islet autoantibodies were positive in only one case.

Causality assessment using the Naranjo algorithm indicated a probable to highly probable relationship between PD-1/PD-L1 inhibitor therapy and CIADM in all cases. All patients required lifelong insulin therapy following diagnosis. After achieving glycemic stabilization, immunotherapy was reinitiated in most cases without exacerbation of hyperglycemia.

These findings position CIADM as a rare but severe immune-related adverse event associated with ICIs. Routine glucose monitoring during treatment may support early detection. Careful metabolic management allows continuation of oncologic therapy, reinforcing the importance of coordinated multidisciplinary care.