Real-World Incidence of Immune-Related Adverse Events Associated with Nivolumab Plus Ipilimumab in Patients with Advanced Renal Cell Carcinoma: A Retrospective Observational Study

Real-world incidence of immune-related adverse events (irAEs) associated with nivolumab plus ipilimumab in patients with renal cell carcinoma (RCC) has been rarely demonstrated. The present study aims to report the safety outcomes of this combination therapy in the real-life population. We conducted a multi-institutional retrospective observational study that assessed the incidence and severity of irAEs associated with nivolumab plus ipilimumab in 41 Japanese patients with metastatic and/or locally advanced RCC. The irAEs were classified into endocrine and non-endocrine irAEs. The median age and follow-up period were 68 years and 13.0 months, respectively. Endocrine irAEs were observed in 66% of patients, including hypopituitarism in 44%, hyperthyroidism in 41%, and primary hypothyroidism in 22%, while non-endocrine irAEs were observed in 54%. All patients experiencing hypopituitarism presented with adrenocorticotropic hormone deficiency, causing secondary adrenal insufficiency, which required permanent corticosteroid replacement therapy. There was an association between the incidence of endocrine irAEs and high-grade non-endocrine irAEs other than skin-related irAEs (p = 0.027). When patients experienced two or more endocrine irAEs, they had a 35% chance of experiencing high-grade non-endocrine irAEs other than skin-related irAEs. Nivolumab plus ipilimumab may lead to a high prevalence of endocrine irAEs in "real-world " patients. Endocrine irAEs may be associated with non-endocrine irAEs other than skin-related irAEs.