Immune Checkpoint Inhibitor-Associated Type 1 Diabetes Mellitus: Case Series, Review of the Literature, and Optimal Management

With the introduction of immune checkpoint inhibitors into clinical practice, various autoimmune toxicities have been described. Antibodies targeting the receptor:ligand pairing of programmed death receptor-1 (PD-1) and its cognate ligand programmed death-ligand 1 (PD-L1) in rare reports have been associated with autoimmune diabetes mellitus. We report 2 cases of rapid-onset, insulin-dependent, type 1 diabetes mellitus in the setting of administration of nivolumab, a fully human monoclonal antibody to PD-1, and atezolizumab, a humanized monoclonal antibody to PD-L1. This appears to be the first report of autoimmune diabetes mellitus associated with atezolizumab. In addition, we provide a brief review of similar cases reported in the literature and a discussion of potential mechanisms for this phenomenon and propose a diagnostic and treatment algorithm.