Incidence of endocrine toxicities in patients with solid tumor malignancies receiving curative-intent immune checkpoint inhibitor (ICI) therapy: A single institution experience

IntroductionImmune checkpoint inhibitors (ICIs) are used across many solid tumor malignancies. The mechanism varies depending on the agent but ultimately leads to immune system activation by targeting key regulators of immune tolerance. Toxicities occur due to persistent activation of the immune system that can manifest in nearly all organs, including endocrinopathies. Although recognition has improved, the incidence of endocrinopathies should be evaluated in the real-world setting. The primary objective was to evaluate the incidence of select endocrine toxicities secondary to curative-intent ICI therapy in patients with solid tumor malignancies.MethodsThis was an observational, retrospective, single-center, cohort study of patients with solid tumor malignancies who received ICIs for curative intent at our institution. Patients had to be ≥ 18 years old and received ICI therapy between May 1, 2022 and March 30, 2023.ResultsFive hundred ten patients were included. Majority of patients received pembrolizumab or nivolumab, and the most common malignancies were breast (28%), melanoma (24%), and non-small cell lung cancer (16%). Twenty-five patients (4.9%) developed an endocrine toxicity with a median onset of 103 days. Hypothyroidism was the most common endocrine toxicity (52%). Nearly all endocrine toxicities were of Grade 2 severity (92%) with no Grade ≥ 4 events.ConclusionWe observed an incidence of endocrine toxicities of 4.9% with a median onset of 103 days in patients with solid tumor malignancies receiving curative intent ICI therapy. Generalizability of these results may be impacted by the exclusion of documented stage IV disease and palliative intent treatment.