Infectious complications in patients treated with immune checkpoint inhibitors

Objective: Immune checkpoint inhibitor (ICI) antibodies constitute a new generation of cancer treatments, associated with immune-related adverse events (irAEs). A previous retrospective study of patients with metastatic melanoma (treated mostly with anti-CTLA4 antibodies) reported a serious infection rate of 7.3%. The main risk factors were corticoids and infliximab use. We sought to describe infections and risk factors among patients receiving anti-PD-1/PD-L1 ICIs. Patients and methods: We reviewed 200 medical records sampled randomly from a French prospective registry, which collates patients treated with anti-PD-1/PD-L1 ICIs. We recorded demographic data, the occurrence of irAEs, immunosuppressant use, and the outcome. Results: Thirty-six patients (18%) experienced an infection by a median (interquartile range) of 47 (19.2-132) days after initiation of the ICI. Twenty-one patients (58.3%) had a lung infection, seven (19.4%) had a skin infection, seven (19.4%) had a urinary tract infection, and all of them received antibiotics. The infection was generally mild, and the patients were treated as outpatient. There were no infection-related deaths and no opportunistic infection. Sixty percent of the patients were being treated for metastatic melanoma and 35.5% for non-small cell lung cancer, and 106 irAEs (mostly grade II) were reported. Forty-seven patients received steroids for cancer symptoms or irAEs, and five received immunosuppressants during the immunotherapy. We did not observe any association between corticosteroid or immuno-suppressant use and the occurrence of an infection. Conclusion: The infection rate in patients treated with an anti-PD-1/PD-L1 ICI was 18%, without any severe or opportunistic infection. The occurrence of an infection was not associ-ated with corticosteroid or immunosuppressant use. (C) 2020 Elsevier Ltd. All rights reserved.