Immune checkpoint inhibitor–related adverse events: Real-world experience from a single veterans’ affairs medical center

Background Immune checkpoint inhibitors (ICIs) are antineoplastic agents associated with a multitude of immune-related adverse events (irAEs). Available data from clinical trials include highly selective patient populations which may limit their applicability to real-world clinical practice. Methods We present a retrospective cohort study of cancer patients treated with ICI therapy at the Zablocki VA Medical Center between 2014 and 2021. Information on demographics, cancer diagnosis, type of therapy, treatment duration, comorbidities, irAE type, and overall survival were collected. Results We identified 187 patients who received at least one dose of ICI. About half the patients experienced at least one irAE, the most common categories being fatigue, pulmonary, and endocrine irAEs. Approximately half of the irAEs were diagnosed within the first three months of starting ICI therapy, and 60.38% of those who experienced irAEs discontinued ICI therapy. Patients who experienced endocrine or intestinal irAEs had a significantly longer overall survival. Conclusion Immune-related complications due to ICI therapy are common and can frequently lead to treatment discontinuation in the real-world setting. Endocrine and intestinal irAEs may correlate with improved survival. The ICI-treated patients who received palliative radiation therapy to the bone had less irAEs, possibly due to immunogenic cell death.