Immune-Mediated Liver Injury From Checkpoint Inhibitors Requiring Supratherapeutic Corticosteroid and Mycophenolate Treatment

A 43-year-old woman with metastatic adrenocortical carcinoma from the left adrenal gland for which she was prescribed therapeutic mitotane was found to have grade 4 immune-mediated liver injury caused by checkpoint inhibitors that was unresponsive to standard-dose corticosteroids. Mitotane inhibits steroidogenesis, induces CYP3A4, increasing steroid metabolism, and can cause adrenal insufficiency. Thus, supratherapeutic steroid doses were required for anti-inflammatory response along with mycophenolate. To our knowledge, this is the first case to describe a patient concurrently receiving mitotane and pembrolizumab with an immune-related adverse event requiring interdisciplinary care, with insights into steroid physiology and immune-mediated liver injury caused by checkpoint inhibitors necessitating a customized treatment plan.