The Relative Risk of Immune-Related Liver Dysfunction of PD-1/PD-L1 Inhibitors versus Chemotherapy in Solid Tumors: A Meta-Analysis of Randomized Controlled Trials

Background: Immune checkpoint inhibitors (ICIs) have made a significant breakthrough in the treatment of solid tumors; however, their use also generates unique immune-related adverse effects (irAEs). Here, we performed a systematic review and meta-analysis to assess the risk of immune-related liver dysfunction between in patients treated by PD-1/PD-L1 inhibitors exclusive and chemotherapy. Methods: A comprehensive search of multiple databases identified eligible studies, including randomized controlled trials (RCTs) with PD-1/PD-L1 inhibitors exclusive and chemotherapy in patients with different solid tumors was carried out. The elevations of ALT (Alanine aminotransferase) and AST (Aspartic aminotransferase) were used to evaluate liver dysfunction. The relative risk and 95% confidence intervals were calculated and analyzed by Review Manager 5.3 and STATA version 12.0 statistical software. Results: After screening and eligibility assessment, a total of 5638 patients from 12 RCTs were included in our meta-analysis. In comparison with chemotherapy, patients treated with PD-1/PD-L1 inhibitors exclusive showed an increased incidence of all-grade ALT/AST elevations (ALT: RR 1.52, 95% CI: 1.09-2.13, p = 0.01; AST: RR 1.96, 95% CI: 1.37-2.81, p=0.0002). Patients receiving PD-1 inhibitors showed the significantly higher risk of all-grade ALT/AST elevations incidence than those receiving chemotherapy (ALT: RR 1.47, 95% CI: 1.05-2.07, p = 0.03; AST: RR 1.90, 95% CI: 1.32-2.73, p = 0.0005). However, no significant difference was found between PD-L1 inhibitor and chemotherapy group. Moreover, for non-small cell lung cancer (NSCLC) and urothelial carcinoma (UC), patients treated with PD-1/PD-L1 inhibitors exclusive exhibited a significant higher risk of all-grade ALT elevation incidence (NSCLC: RR 1.92, 95% CI: 1.23-3.02, p = 0.004; UC: RR 3.36, 95% CI: 1.12-10.06, p = 0.03) and all-grade AST elevation incidence (NSCLC: RR 2.37, 95% CI: 1.45-3.87, p = 0.0005; UC: RR 4.47, 95% CI: 1.30-15.38, p = 0.02) than chemotherapy. Conclusions: The meta-analysis confirms that PD-1/PD-L1 inhibitors exclusive pose an increased risk of immune-related liver dysfunction than chemotherapy. PD-1/PD-L1 blockade in NSCLC and UC increase the risk of immune-related liver dysfunction, but not in MM and HNSCC.