Haematological toxicities with immune checkpoint inhibitors in digestive system tumors: a systematic review and network meta-analysis of randomized controlled trials.

This study aims to comprehensively evaluate the hematologic toxicity profiles, toxicity spectrum, and safety rankings of immune checkpoint inhibitors (ICIs) used for digestive system tumors. The PubMed, Cochrane Library, Web of Science, and Embase databases were systematically searched from inception to August 2024 to identify randomized controlled trials (RCTs). The primary outcome was anemia, while secondary outcomes included neutropenia, neutrophil count decreased, thrombocytopenia, platelet count decreased, leukopenia, white blood cell (WBC) count decreased, lymphocyte count decreased, and febrile neutropenia (FN). Subgroup analyses were performed based on tumor type, country category, study phase, ICI regimen, control group, chemotherapy regimen, ICI plus different chemotherapy regimens. Two reviewers independently selected the studies, extracted data according to pre-specified criteria, and assessed the risk of bias using the Cochrane Collaboration risk of bias tool. RevMan 5.4 software was utilized to visualize the risk of bias assessments. Stata 16.0 was used to conduct network meta-analysis, sensitivity analysis and meta-regression. 25 phase II and III RCTs (n = 15216) were included. The general safety of ICIs ranked from high to low for grade 1-5 anemia were as follows: avelumab, nivolumab, pembrolizumab, sintilimab, camrelizumab, and tislelizumab. For grade 3-5 anemia, the general safety profile of the ICIs were as follows, from highest to lowest: avelumab, nivolumab, pembrolizumab, sintilimab, and camrelizumab. Compared to chemotherapy, treatment-related hematologic toxicities with ICIs occurred primarily in grade 1-5 anemia, neutropenia, thrombocytopenia, leukopenia, and WBC count decreased. Taking ICI monotherapy, nivolumab plus ipilimumab were generally safer than taking chemotherapy, one ICI drug with chemotherapy, or two ICI drugs with chemotherapy. In terms of grade 1-5 hematologic toxicities, tislelizumab had the highest risk of neutropenia and leukopenia; the primary treatment-adverse events (AEs) for sintilimab was neutrophil count decreased and WBC count decreased; the primary treatment-related AE associated with nivolumab was platelet count decreased; camrelizumab posed the highest risk for lymphocyte count decreased. In terms of grade 3-5 hematologic toxicities, pembrolizumab was predominantly linked to neutropenia; sintilimab showed the greatest risk for neutrophil count decreased, platelet count decreased, and lymphocyte count decreased; avelumab was most associated with WBC count decreased. FN primarily manifested as grade 3-5, with camrelizumab having the highest risk. Among agents used in gastric or gastroesophageal junction cancer, avelumab demonstrated the most favorable safety profile for anemia. Each treatment regimen has its unique safety profile. Early identification and management of ICI-related hematologic toxicities are essential in clinical practice.Systematic Review Registration: PROSPERO CRD42024571508.