Immunotherapy and hypophysitis: clinical presentation, treatment, and biologic insights

Introduction Advances in immunotherapy have transformed the management of metastatic melanoma and generated encouraging results in the treatment of other malignancies. Autoimmune side effects from these agents, termed immune-related adverse events (IRAEs), are diverse and can include multiple endocrinopathies. Ipilimumab-induced hypophysitis (IH) is a recently recognized endocrine IRAE. Methods This review summarizes published data and experience from our center on the incidence, presentation and management, and proposed mechanisms for immunotherapyrelated hypophysitis, with a focus on patients treated with ipilimumab (Ipi). Conclusion Hypophysitis occurs in a significant minority of patients treated with Ipi, in contrast to the relative rarity of idiopathic autoimmune hypophysitis or hypophysitis after treatment with other immunotherapies. Recently published cohorts have described the clinical presentation and management of IH and longitudinal outcomes in these patients. Additional studies with Ipi and other emerging agents have helped identify potential risk factors for the development of immunotherapy-related hypophysitis and possible underlying mechanisms for IH. Clarification of the mechanism(s) for IH may enhance our understanding of idiopathic autoimmune hypophysitis and could have potential therapeutic applications.