Incidence and characteristics of emergency department presentations during immune checkpoint inhibitor therapy.

Abstract

e14164 Background: Immune checkpoint inhibitors (ICIs) have emerged as a novel class of anticancer agents with unique response and toxicity profiles. Oncology patients undergoing ICI therapy can present acutely with cancer- or treatment-related complications, but knowledge of these acute clinical presentations is limited. The objective of this study was to investigate the features of emergency department (ED) presentations of patients undergoing ICI therapy. Methods: A retrospective chart review was performed of 1044 adult oncology patients at a single institution from 2010-2018 who underwent treatment with one or more ICI. The number of patient visits to the ED during and up to one month following ICI treatment was recorded, in addition to various clinical and demographic data. These data were compared based on stratification by number of ED visits (0 visits, 1 visit, or ≥2 visits) using Likelihood Ratio Chi-Square and Mann–Whitney U tests. Results: Mean age for the 1044 patients receiving ICI therapy was 64±13 years, with 57% males and 43% females. Primary cancer distribution included 42.0% lung, 24.2% melanoma, 6.9% head & neck, 5.1% kidney, 4.0% bladder, and 17.8% other malignancy. 83.4% of patients were treated with a single ICI, 14.9% with 2 ICIs, and 1.2% with 3-4 ICIs. 56.0% of patients had no ED visits during their treatment duration, 27.0% had 1 ED visit, and 17.0% had ≥2 ED visits. Patients with lung, kidney, and bladder cancer were more likely to present to the ED (p = < 0.001). Black ethnicity was the only demographic feature associated with more ED visits (p = 0.017). Patients receiving ≥2 ICIs or monotherapy with nivolumab, pembrolizumab, or atezolizumab more frequently presented to the ED compared to other ICIs (p = < 0.001). Patients with 1 or ≥2 ED visits had longer durations of ICI therapy (136±12 days and 216±15 days, respectively) compared to patients with no ED visits (127±8 days) (p = < 0.001). Patients with no ED visits also demonstrated better overall survival (p = < 0.001). Conclusions: More frequent ED visits during ICI therapy is statistically associated with several key clinical factors, including primary cancer type, ethnicity, specific ICI agent, ICI therapy duration, and overall survival.