SAT-677 A Case of Opdivo Induced Type 1 Diabetes

BACKGROUND: Opdivo, or Nivolumab is an immunotherapy medication that works as a checkpoint inhibitor. It is used in various cancers not amenable to surgery, including lung cancer and metastatic melanoma. Opdivo has proven to be a beneficial treatment, though it is not without complications including thyroid dysfunction, hypophysitis, and autoimmune induced diabetes. Clinical Case: An 80 year old female with a PMH of type 2 diabetes mellitus, hypertension, hyperlipidemia, and melanoma with metastasis to the bone was evaluated by endocrinology for acute worsening of her type 2 diabetes. The patient had been diagnosed with diabetes 10 years prior. She was well controlled on 22 units of levemir and Janumet. Her baseline HbA1c was 6.7%. She had no known complications from her diabetes. Four months prior to presentation she had been started on monthly Opdivo infusions for her metastatic melanoma, which she was tolerating well. On presentation to the hospital, she had persistent hyperglycemia in the high 400’s, an elevated anion gap, and an elevated betahydroxybutyrate. She had no signs of acute infection and no significant changes in her diet or activity level. She was started on an insulin drip for diabetic ketoacidosis until her anion gap resolved. At discharge she was continued on 22 units of levemir, a humalog sliding scale, and Janumet. At that time it was unclear what precipitated her acute change in glycemic control. At her follow up endocrinology appointment several labs were drawn including a c-peptide, though antibodies were not obtained. Her c-peptide was less than 0.1 with a concurrent blood glucose value of 370. It was determined that she had developed autoimmune induced diabetes secondary to Opdivo therapy and would require life long insulin therapy. Her Janumet was discontinued. She was started on a T-slim insulin pump and Dexcom G6 sensor, with improvement in her glucose control. Her Opdivo treatments were discontinued. She has since developed worsening metastasis in her femur and will be started on Yervoy. Yervoy also carries a risk of further endocrine disorders, including increased risk of hypophysitis. Discussion: Acute changes in glycemic control warrants further investigation to determine the underlying precipitating factor. The most common complications of Opdivo are rashes and fatigue, though endocrinopathies have been noted in several patients. It was crucial in this patient to identify this side effect of Opdivo, as it helped to prevent further episodes of DKA. Careful review of recent medication changes helped identify this uncommon complication of Opdivo and prompted a timely change in her diabetes care regimen.