Immunotherapy-Induced Anterior Hypophysitis

Immunotherapy-based regimens are currently the standard treatment for many different types of cancers. Monoclonal antibodies against cytotoxic T lymphocytes antigen (CTLA-4), programmed cell death protein-1 (PD-1), and PD-1 ligand (PD-L1) are the major subgroups of immune checkpoint inhibitors, which are being used widely in the treatment of various malignancies. They function by reactivating the immune system against the tumor cells but can also trigger autoimmune side effects, which are termed immune-related adverse effects (irAEs). In this report, we present a case of irAEs in a patient treated for colorectal cancer with combination therapy with ipilimumab (anti-CTLA-4 antibody) and nivolumab (anti-PD-1 antibody).