Abstract
Immune checkpoint blockade including programmed cell death 1 pathway inhibition with agents such as nivolumab is gaining ground in a wide array of malignancies, so far demonstrating significantly improved survival rates even in metastatic, often multiply pretreated settings. Although targeted in nature and generally well-tolerated compared with conventional anticancer treatments, these agents are often linked to a newly emerged group of adverse reactions, referred to as immune-related adverse events, which can also affect endocrine organs. This is a case report of a patient who received nivolumab for the treatment of recurrent metastatic non-small cell lung cancer and developed primary hypothyroidism and secondary adrenal insufficiency caused by selective pituitary dysfunction (with preservation of all other endocrine functions). After hormone replacement with daily administration of T4, T3 and hydrocortisone, the patient achieved complete recovery. Adequate characterisation of these rare yet potentially severe entities is essential for prompt diagnostic and therapeutic interventions that will permit us to fully benefit from these new agents' therapeutic potential.