Second-line immunosuppressant administration for steroid-refractory immune-related adverse events in patients with lung cancer

BACKGROUND: Evidence for use of second-line immunosuppressants for immune-related adverse events (irAEs) is inadequate. Therefore, a multicenter analysis should assess the efficacy of second-line immunosuppressants for severe irAEs associated with different malignant diseases. METHODS: This descriptive study aims to investigate the effects of second-line immunosuppressants on corticosteroid-refractory irAEs in patients with lung cancer. We analyzed the effects of second-line immunosuppressants on underlying lung cancer and associated adverse effects. RESULTS: Our study included 4589 patients who had received immune checkpoint inhibitor treatment, with 73 patients (1.6%) developing irAEs requiring second-line immunosuppressants. The most commonly observed irAE was pneumonitis (26 patients), followed by hepatobiliary disorders (15 patients) and enteritis (14 patients). We found a confirmed response rate of 42.3% for pneumonitis, which was lower than the response rates of 86.7% for hepatobiliary disorders and 92.9% for enteritis. The time from the start of corticosteroid therapy to the addition of a second-line immunosuppressant correlated significantly with the resolution of irAE to Grade 1 (correlation coefficients of r = 0.701, p < 0.005). The median progression-free survival and duration of response of underlying lung cancer from second-line immunosuppressant administration were 2.1 and 3.0 months, respectively. Of the patients with irAE, 27.4% developed infections and 5.5% might die due to infection. CONCLUSION: Second-line immunosuppressant response was confirmed in 72.2% of irAEs in patients with lung cancer, with lower response rates observed in irAE pneumonitis compared to other irAEs.