A case of rapidly progressive insulin-dependent diabetes mellitus without islet autoantibodies developed over two years after the first dose of nivolumab.

The case was an 80-year-old Japanese man. He was diagnosed with right renal cell carcinoma when he was 74. After laparoscopic radical nephrectomy, the patient received interferon, sorafenib, axitinib, and nivolumab therapy. The patient developed rapid progressive insulin-dependent diabetes mellitus (DM) after 46 courses of nivolumab monotherapy (772 days from the first nivolumab treatment). Glutamic acid decarboxylase antibody, islet cell cytoplasmic antibody, islet cell antigen-2 antibody, insulin antibody, and zinc transporter 8 antibody were all negative. Human leukocyte antigen (HLA) typing showed DRB1*09:01, DRB1 13:02, DQB103:03, and DQB1 *06:04. Multiple daily insulin injections were started. However, controlling his blood glucose by standard multiple daily insulin injection treatments was difficult. The patient survived more than two years after the onset of immune checkpoint inhibitor-associated DM (ICI-DM). This is a valuable report of late-onset ICI-DM with a detailed patient background and clinical course over two years after the first dose of nivolumab.