Immune-related adverse events have emerged as a new challenge and its correlation with survival remains unclear. The goal of our study was to investigate the effect of irAE on survival outcomes in solid tumor patients receiving ICI treatment. This was a retrospective, single-center study at a university hospital involving patients with malignancy who received immune checkpoint inhibitors. Chart review was performed on each patient, noting any irAE, including new events or worsening of previous autoimmune condition after starting treatment with ICI. A total of 155 patients were included, 118 (76.1%) were male, with median age of 64 years. Median follow up time was 36 months. Seventy patients (45.2%) had at least one irAE. Of all irAE, nine (8.1%) were classified as grade 3 or higher according to the CTCAE version 5.0. There was one death secondary to pneumonitis. Median ICI cycles until first irAE onset was 4 (range: 2-99). The objective response rate was higher for patients who developed irAE (18.7% vs. 9.0%; p = 0.001), as was median overall survival (18 months (95% CI, 8.67-27.32) vs. 10 (95% CI, 3.48-16.52) months; p < 0.016) and progression free survival (10 months (95% CI, 5.44-14.56) vs. 3 months (95% CI, 1.94-4.05); p = 0.000). The risk of death in patients with irAE was 33% lower when compared to patients without such events (hazard ratio (HR): 0.67; 95% CI, 0.46-0.99; p = 0.043). Development of irAE predicted better outcomes, including OS in patients with advanced solid tumors treated with ICI. Further prospective studies are needed to explore and validate this prognostic value.
Keywords: immune checkpoint inhibitors; immune-related adverse event; prognosis; survival.