Evaluation of emergency department visits and immune-related adverse effects (irAEs) in patients treated with nivolumab.

Introduction: The development of immune checkpoint inhibitors (ICIs) represents one of the most significant advancements in cancer treatment over the past decade. Nivolumab, a widely used ICI, has been incorporated into the therapeutic regimens for various cancers. As with any drug, this drug also has side effects, including class-specific immune-related adverse effects (irAEs). Although irAEs are not rare, their diagnosis can be challenging. This study examines the emergency department (ED) visits of patients undergoing nivolumab therapy, focusing on diagnostic challenges, evaluating the management, and outcomes of irAEs in the ED setting.

Material And Methods: A retrospective cohort study was conducted on adult patients who received nivolumab therapy for any cancer between April 1, 2018, and March 31, 2023, at a large, urban tertiary care center. In this study, we evaluated the ED visits of patients receiving nivolumab. In addition to previous studies, we evaluated irAEs in detail (percentage, recognizability, risk factors, reasons for late recognition, and outcome). Patient data were collected from electronic medical records and patient's medical files. The anamnesis, laboratory, and imaging results, ED management, and consultation notes were examined separately for each ED visit. Logistic regression models were employed to identify significant univariable predictors of ED visits and irAEs.

Results: A total of 199 patients were included in the study, all of whom had metastatic cancer. Of these, 154 patients (77.4%) received nivolumab therapy for non-small cell lung cancer. Most patients (71.9%, n = 143) had at least one additional comorbidity. One hundred and eleven patients (55.8%) presented to the ED. Hypertension (OR: 2.425, 95% CI: 1.226-4.795, p = 0.011) and chronic obstructive pulmonary disease (OR: 2.489, 95% CI: 1.133-5.468, p = 0.023) were identified as risk factors for ED visits. A total of 21 irAEs were diagnosed (14 in ED, 6 in the oncology clinic, and 1 in the inpatient ward). Univariate analysis found no significant association between irAE diagnosis and any specific factors.

Conclusion: A significant proportion of the patients treated with nivolumab for advanced cancer present to ED for ICI-related adverse events, although most cases were not attributable to irAEs. Due to the vague symptomatology of irAEs, their recognition and diagnosis in the ED can be challenging. Close collaboration between ED physicians and oncologists is paramount to the management of patients with cancer in the ED.