Supplementary Material for: Effects of Early Short-Course Corticosteroids on Immune-Related Adverse Events in Non-Small Cell Lung Cancer Patients Receiving Immune Checkpoint Inhibitors

Introduction: In real-world practice, most non-small cell lung cancer (NSCLC) patients receiving combined immunochemotherapy are exposed to short-course corticosteroids following immune checkpoint inhibitor (ICI) infusion to prevent chemotherapy-related adverse events. However, whether this early short-course corticosteroid use prevents immune-related adverse events (irAEs) remains unknown. Methods: Between January 1st 2015 and December 31st 2020, NSCLC patients who received at least one cycle of ICI with or without chemotherapy were enrolled. Early short-course corticosteroids were defined as corticosteroids administered following ICI injection and before chemotherapy on the same day and no longer than 3 days afterwards. The patients were categorized as either “corticosteroid group” or “non-corticosteroid group” depending on their exposure to corticosteroid premedication. The frequencies of irAEs requiring systemic corticosteroid use and irAEs leading to ICI discontinuation were compared between the two groups, and exploratory survival analyses were performed. Results: Among 252 eligible patients, 137 patients were categorized as “corticosteroid group,” and 115 patients as “non-corticosteroid group”. The corticosteroid group enriched patients in the first-line setting (n = 75, 54.7%), compared to the non-corticosteroid group (n = 28, 24.3%). Thirty patients (21.9%) in the corticosteroid group and 35 patients (30.4%) in the non-corticosteroid group developed irAEs requiring systemic corticosteroid use (Odds ratio [OR], 0.64; 95% confidence interval [CI], 0.35 to 1.18; p = 0.15). Eight patients (5.8%) in the corticosteroid group, as compared with 18 patients (15.7%) in the non-corticosteroid group, permanently discontinued ICI due to irAEs (OR, 0.34; 95% CI, 0.12 to 0.85; p = 0.013). Conclusion: Early short-course corticosteroids following each ICI injection may reduce the rate of irAEs that leads to ICIs discontinuation, warranting further investigation of its prophylactic use to mitigate clinically significant irAEs.