Wang Y, et al. - In this investigation including 20,128 patients, researchers assessed the incidences of treatment-related adverse events of programmed cell death (PD-1) and programmed cell death ligand 1 (PD-L1) inhibitors and the differences between different drugs and cancer types. Data reported that the overall incidences of all-grade adverse events were 66.0% and of grade 3 or higher adverse events were 14.0%. Fatigue, pruritus, and diarrhea were the most common all-grade adverse events. Fatigue, anemia, and aspartate aminotransferase increase were the most common grade 3 or higher adverse events. The most frequent all-grade endocrine immune-related adverse events were hypothyroidism and hyperthyroidism. Compared to pembrolizumab and grade 3 or higher adverse events, nivolumab was linked to higher mean incidences of all-grade adverse events. According to this systematic review and meta-analysis, different inhibitors of PD-1 and PD-L1 appear to have various adverse events related to treatment. An important guide to clinical practice may be a comprehensive summary of treatment-related adverse events for inhibitors of PD-1 and PD-L1 in clinical trials.