Hospitalization for immune related toxicity and overall survival (OS) among patients with metastatic non-small cell lung cancer (NSCLC) treated with first-line pembrolizumab

e21215 Background: Few studies have investigated the association between patients with NSCLC hospitalized due to complications of ICI and subsequent OS. Immune related adverse events (irAEs) are autoimmune syndromes, side effects of ICIs. We evaluated the rates of irAEs among patients with metastatic NSCLC hospitalized within 1 year of pembrolizumab treatment and OS. Methods: This retrospective study included 102 patients (out of 411 total patients screened) with Stage IV NSCLC treated with a first-line pembrolizumab regimen (alone or in combination with chemotherapy) at the Ohio State University from 2018-2022 who developed an irAE. A chart review was completed for patient demographics, unplanned hospitalizations (irAE or any reason) within 1 year of ICI, and type of irAEs leading to hospitalization. Descriptive statistics were summarized and compared by irAE hospitalizations (Yes vs No) or any reason hospitalizations (Yes vs No). Kaplan-Meier survival analysis and log-rank test were used to assess the associations between these two groups with OS. Results: Twenty-one percent (21/102) of patients were hospitalized for irAE within 1 year, for the following irAE types: 7 pneumonitis (33.3%), 6 colitis (28.6%), 2 dermatitis (9.5%), 1 hepatitis (4.8%), 1 myalgia (4.8%), 1 neurological (4.8%), and 1 hypophysitis (4.8%). 68 were hospitalized for any reason including irAE, infections, cancer progression, and pain. Patients age, gender, race, and body mass composition were similar between two groups. Patients with irAE hospitalization had shorter OS (13.8 m, 95% CI 2.73-NR) than those without irAE hospitalization (53.6 m, 95% CI 33.18-NR, p = 0.0105). Hospitalization irAE rates were not significantly different between pembrolizumab alone and pembrolizumab-chemotherapy, however overall hospitalization rate was higher in pembrolizumab-chemotherapy (77%) than pembrolizumab alone (55%), p = 0.0214. Conclusions: This study suggests patients who are hospitalized following ICI treatment may have worse outcomes. Hospitalization rates overall were higher for patients treated with pembrolizumab-chemotherapy than pembrolizumab alone. Further investigation is needed to confirm these findings as our study was limited to patients who experienced irAEs during treatment.