Abstract
With the increased use of immune checkpoint inhibitors (ICIs) in lung cancer, which are of great benefit to patients, more and more immune-related adverse events (irAEs) are being reported. Checkpoint inhibitor pneumonitis (CIP) is one of the most challenging adverse events, which pose a huge challenge to clinical diagnosis and treatment, and its incidence in the real world is greatly underestimated. Currently, the treatment of CIP mainly depends on the use of glucocorticoids. As for steroid-resistant CIP, there is no unified standardized treatment strategy. Herein, we report a case of steroid-resistant CIP induced by pembrolizumab in a patient with advanced non-small cell lung cancer (NSCLC), in which their symptoms were successfully controlled with pirfenidone.