Discontinuation of Immune Checkpoint Inhibitor due to irAEs in NSCLC Patients With EGFR Mutation

Immune checkpoint inhibitors (ICIs) have revolutionized advanced non-small cell lung cancer (NSCLC) treatment. Even patients with epidermal growth factor receptor (EGFR)-mutated NSCLC may choose an ICI after failure of EGFR-tyrosine kinase inhibitor treatment. ICI-mediated immune-related adverse events (irAEs) may prompt NSCLC patients to discontinue their treatment. This study evaluated the effect of ICI treatment discontinuation on the prognosis of patients with EGFR-mutated NSCLC.

We performed a retrospective study that reviewed the clinical courses of patients with EGFR-mutated NSCLC treated with ICI therapy from February 2016 to February 2022. 'Discontinuation' was defined as failure to receive at least two treatment courses of ICI due to grade 2 irAEs (grade 1 in the lung) or higher in patients responding to ICI.

During the study period, 13 of 31 patients discontinued ICI therapy due to irAEs. Survival from the initiation of ICI therapy was significantly longer in patients who discontinued ICI therapy compared with those who did not discontinue. In uni- and multivariate analyses, 'discontinuation' was a favourable factor. There was no significant difference in survival from ICI initiation between patients with grade 3 or higher irAEs and those with grade 2 or lower irAEs.

In this patient cohort, discontinuation of ICI therapy due to irAEs did not adversely affect prognosis in patients with EGFR-mutant NSCLC. Our results suggest that when treating patients with EGFR-mutant NSCLC with ICIs, chest physicians should consider discontinuing ICI with close monitoring.