A case of acute myocarditis induced by PD-1 inhibitor (sintilimab) in the treatment of large cell neuroendocrine carcinoma

The combination of Sintilimab with pemetrexed/platinum has become the first-line treatment for non-squamous non-small-cell lung carcinoma (NSCLC). Here, we report a patient with metastatic large cell neuroendocrine carcinoma (LCNEC) treated with Sintilimab for five cycles who developed shortness of breath after activity. The level of creatine kinase (CK), creatine kinase-MB (CK-MB) and cardiac troponin T (cTnT) were significantly increased. The cardiac MR suggested that heart function was slightly decreased. Considering that the patient did not take any illicit drugs, without history of autoimmune disease, coronary heart disease, arrhythmia, or chronic heart failure, we diagnosed the patient with Sintilimab-induced myocarditis. The symptoms alleviated after rapid use of glucocorticoids. Myocarditis is a rare immune-related adverse events (irAEs), especially myocarditis induced by programmed cell death receptor-1 (PD-1) inhibitor in the treatment of LCNEC.