Two severe adverse events triggered by an anti-PD-1 immune checkpoint inhibitor in an advanced lung cancer patient: a case report and review of the literature.

Anti-programmed death 1 (PD-1) immune checkpoint inhibitors have produced robust tumor responses in several solid tumors including lung cancer by enhancing the antitumor activity of the immune system. In general, the adverse events triggered by anti-PD-1/PD-L1 mAbs appear to be less severe when compared with traditional chemotherapy. However, a subgroup of patients will experience various autoimmune adverse events, such as skin, gastrointestinal, pulmonary, hepatic, renal, and endocrine events, among others. In previous studies, only one irAE was reported in a patient who received immunotherapy. However, in this report, we presented an advanced non-small cell lung cancer patient who was positive for PD-L1 in 20% of tumor cells and negative for actionable molecular markers such as KRAS, EGFR, ALK, MET, and ROS1 alterations. He received a PD-1 inhibitor combined with chemotherapy according to the guidelines of the Chinese Society of Clinical Oncology (CSCO) non-small cell lung cancer [2020] and experienced severe hepatitis and pneumonitis successively, which were recovered after the treatment of systemic glucocorticoids. This situation increased the difficulty of diagnosis and treatment of immune-related adverse events (irAEs). This case illustrates the potential toxicity caused by immunotherapy, and more attention should be paid to its prevention, treatment, and association with antitumor efficacy. Multidisciplinary discussions should be undertaken to improve patient prognosis.