DIABETIC KETOACIDOSIS ASSOCIATED WITH ALPELISIB TREATMENT OF METASTATIC BREAST CANCER

Abstract

Objective: Alpelisib-induced diabetic ketoacidosis (DKA) is a rare, but life-threatening, adverse event. There have been only 2 reported cases in the literature. We describe such a case, with emphasis on the importance of screening and achieving adequate glycemic control prior to and after initiation of therapy.

Methods: A 49-year-old woman, known to have advanced breast cancer, presented with a 3-day history of nausea, vomiting, and diffuse abdominal pain. She had started alpelisib at 300 mg/day 2 months prior to presentation, after failing other options. She was diagnosed with DKA using her clinical and laboratory features, leading to treatment with hydration and intravenous insulin therapy.

Results: Laboratory data showed high anion gap metabolic acidosis, hyperglycemia, and ketonemia with negative GAD-65 antibodies, leading to the diagnosis of alpelisib-associated DKA. Alpelisib was held, and she was treated with intravenous insulin and hydration. When DKA and hyperglycemia resolved, alpelisib was resumed at a lower dose (200 mg/day) and her blood glucose was managed using a regimen combining insulin and metformin.

Conclusion: Phosphatidylinositol-3 kinase signaling is important for the metabolic actions of insulin, and alpelisib has been associated with severe hyperglycemia. Metformin is the first-line treatment, however when DKA is the presenting syndrome, insulin needs to be considered. Blood glucose and hemoglobin A_1c should be checked prior to treatment initiation and monitored closely after drug initiation. DKA, albeit rare, must be considered in an acutely ill, alpelisib-treated patients presenting with metabolic acidosis, and if drug discontinuation is not an option, insulin treatment may be required to control glycemia.