Gastrointestinal toxicities associated with immune checkpoint inhibitors: a disproportionality analysis leveraging VigiBase, the WHO Adverse Drug Reaction Database

With the improvement of people's living standards, gastrointestinal adverse reactions caused by various adverse factors have attracted more and more people's attention. A recent study has indicated that coronavirus disease 2019 (COVID-19) could also invade the gastrointestinal tract, leading to gastrointestinal adverse reactions (Song et al., 2020). In recent years, immunotherapy has provided certain effects for some patients with advanced malignant tumors. A microencapsulation of immunoglobulin Y (IgY) was reported to provide an effective way to preserve IgY and improve its performance in the gastrointestinal tract (Zhang J et al., 2020). Immune checkpoint inhibitors (ICIs) can significantly improve the survival of some advanced malignant tumors, especially metastatic malignant melanoma and lung cancer (Afzal et al., 2018; Madden and Kasler, 2019). They include anti-cytotoxic T lymphocyte-associated antigen-4 (anti-CTLA-4) antibodies (ipilimumab and tremelimumab), anti-programmed cell death protein 1 (anti-PD-1) antibodies (nivolumab and pembrolizumab), and anti-programmed death-ligand 1 (anti-PD-L1) antibodies (atezolizumab, avelumab, and durvalumab) (Baxi et al., 2018). Previous studies have shown that ICI combination therapy, such as nivolumab plus ipilimumab, has particular efficacy in lung cancer, renal cell carcinoma, and malignant melanoma (Wolchok et al., 2017; Derosa et al., 2018; Doroshow et al., 2019). However, ICIs may also lead to many immune-related adverse events (irAEs), even causing severe complications in certain cases. The most well-established toxicities from ICI therapy are gastrointestinal irAEs, including enteritis, enterocolitis, microscopic colitis, and gastritis, which have attracted public attention in recent years; reports of such events associated with ICI therapy also have increased (Tandon et al., 2018; de Malet et al., 2019). These gastrointestinal irAEs may generally respond well to corticosteroids and infliximab (Haanen et al., 2017). Although most of these irAEs are low-grade, a lack of detection and timely treatment may incur severe or fatal complications.