Objective To explore the general situation of severe immune-related adverse events (irSAEs) in the real world.

Methods A total of 50 patients who were diagnosed with serious irSAEs in Zhongshan Hospital, Fudan University between June 2018 and June 2020 were included. Clinical data including the basic data, drug use, median onset time, laboratory examination, treatment, and prognosis were recorded and analyzed.

Results The spectrum of severe irSAEs included myocarditis, hepatitis, colitis, pneumonitis, primary adrenal insufficiency, diabetes, and nervous system adverse events. The median age of patients was 61 years, 66% of patients were male, and the median time of onset was 6 weeks after starting immune checkpoint inhibitors (ICIs). Steroids were administered in 45 patients (90%). After intensive treatments, 39 patients (77.5%) recovered, and 11 patients (22.5%) had the outcome of death. Main causes of death were myocarditis and hepatitis. Compared with those recovered, patients who died received higher doses of glucocorticoids (267.27±190.22mg vs105.38±145.49 mg, P=0.021), and more patients were additionally given another immunosuppressant (10.0% vs 6.0%, P=0.009). In this study, 19 patients were diagnosed with myocarditis. Different from other irAEs usually affecting one organ, myocarditis was more prone to be concurrent with other system irAEs such as hepatitis, myositis, and thyroiditis. Patients who died from myocarditis had higher NT-proBNP (12 844 vs 479.7 pg/mL, P=0.000 6) and cTnT levels (0.928 vs 0.233 ng/mL, P=0.006 4) than those recovered from myocarditis. But no statistical significance existed between the two groups for left ventricular ejection fraction (62.75% vs 65.11%, P=0.348 2).

Conclusions Severe irSAEs affect key organs including heart, liver, lung, and intestine. The prognosis of irSAEs is poor even if high-dose glucocorticoids were administrated.