Gastrointestinal and liver immune-related adverse effects induced by immune checkpoint inhibitors: A descriptive observational study.

Introduction: Immune checkpoint inhibitors (ICIs) are effective agents against several malignancies. However, they are associated with gastrointestinal and liver immune-related adverse events (GI-IrAEs and LI-IrAEs), which can lead to their temporary or permanent discontinuation.

Aim: The aim of this study was to evaluate the efficacy and gastrointestinal and liver toxicity of ICIs in oncological treatments in actual clinical practice.

Material And Methods: Patients with advanced cancer who received at least 1ICI dose between May 2015 and September 2018 were retrospectively assessed.

Results: 132 patients with non-small cell lung cancer (65.15%, n=86); melanoma (22.7%, n=30); renal carcinoma (9.09%, n=12); and other tumours (3%, n=4) were included. The treatments administered were nivolumab (n=82), pembrolizumab (n=28), atezolizumab (n=13), durvalumab (n=2), ipilimumab (n=1) and the antiCTLA-4/PD-1 combination (n=6). In total, 51 patients (38.6%) developed IrAEs, 17 (12.9%) of which experienced GI-IrAEs. Of these, 8 (47%) needed steroids and 1patient required surgery due to intestinal perforation. Grade I Li-IrAEs were observed in 4 patients (3.03%): 2 (50%) required corticosteroids and 1 patient had to discontinue treatment. Four patients (66.6%) who received combination therapy experienced GI-IrAEs. IrAE incidence were not associated with age, gender or drug response.

Conclusions: GI-IrAEs are one of the most common adverse events in patients receiving ICIs. A multidisciplinary approach and a greater understanding of these events could help to reduce morbidity and therapy discontinuation.