A case report of advanced thymoma re-treated with PD-1 inhibitor after initial immune-related pneumonitis.

With the growing use of immune checkpoint inhibitors (ICIs), recurrent immune-related adverse events (irAEs) have become more common after recovery from initial immune toxicity. Here we report one case of anti-PD-1-related pneumonitis in a patient with advanced thymoma, who experienced two episodes of pneumonitis during 10 months of treatment with a PD-1 inhibitor. By reviewing recent advances in ICI-related adverse events, we summarize the clinical characteristics of recurrent immune-related pneumonitis, illustrate potential predictive biomarkers for irAEs, and evaluate the value of resuming anti-PD-1 treatment in this patient. To date, evidence regarding retreatment following improvement from an irAE is scarce, and further clinical trials are needed to address this scenario.