Aim: Immune checkpoint inhibitors (ICIs) have significantly improved prognosis for patients with advanced malignancies. However, ICIs predispose to a spectrum of adverse effects known as immune-related adverse events (irAEs). We aimed to review prevalence of existing irAEs in the months prior to oncology admissions as well re-admission rates, management and outcomes.
Methods: Inpatient medical oncology admissions at Fiona Stanley Hospital (FSH)secondary to irAEs were audited for demographics, ICI treatment, irAE and severity, management, length of stay from January to June in 2022. We also reviewed mortality and readmissions. Outpatient correspondence was reviewed for pre-existing irAEs in the 3 months prior to admission.
Results: Twenty-nine patients were admitted for irAEs under FSH oncology. Approximately 41% of patients were on pembrolizumab, 28% on both ipilimumab and nivolumab, 21% on nivolumab and 10% on durvalumab. Colitis accounted for 34.5% of irAE admissions followed by pneumonitis and hepatotoxicity accounting of 21% and 17% respectively. The mean length of stay was 8.3 days (median 7, range 2-34 days). Grade 3-4 IRAEs accounted for 72% of admissions while grade 2 irAEs accounted for 28%. Fifty-nine percent of patients received intravenous steroids, 41% received oral steroids and 17% of patients required additional immunomodulators. Approximately 69% of patients had grade 1-2 irAEs in the preceding admission. Forty-one percent of patients were readmitted within 6 months and 17% of these were for an irAE. One patient died during audited admission and one patient died during their readmission secondary to the irAE.
Conclusion: Admissions secondary to irAEs are growing. Over 40% of patients received oral steroids raising the possibility of avoiding admissions in the first instance. We found a majority of admitted patients had preceding IRAEs in the outpatient setting. Closer monitoring for these patients in the outpatient setting may suggest prompt diagnoses and treatment potentially preventing hospitalisations.