Jiang Y, et al. - Researchers carried out a systematic review and meta-analysis of clinical trials with Food and Drug Administration-approved immune checkpoint inhibitor (ICI) regimes in patients with advanced solid tumors in order to address the risks of fatal adverse events (FAEs) associated with each ICI regimen. In all included studies, the incidence of FAE in ICI was up to 3.2%. Investigators found that the cytotoxic T-lymphocyte-associated protein-4 (CTLA-4) inhibitors have a significantly increased risk of FAE, while inhibitors of the programmed cell death protein 1 (PD-1) were not. Gastrointestinal toxicity was the most common CTLA-4-related FAE, and pulmonary toxicity was the most common PD-1-related FAE. In addition, they have shown that ipilimumab has significant lethal toxicity depending on the dose.