The Addition of Concurrent Immune Checkpoint Inhibitors for Chemoradiotherapy With Consolidative Immune Checkpoint Inhibitors in Unresectable Cancers: A Systematic Review and Meta-Analysis.
Following the success of chemoradiotherapy (CRT) combined with consolidative immune checkpoint inhibitors (ICIs) in locally advanced tumors, over 30 ongoing randomized controlled trials (RCTs) are investigating the potential benefits of adding concurrent ICIs. To investigate the differences in efficacy and safety between adding and not adding concurrent ICIs to CRT followed by consolidative ICIs, a literature search was conducted in PubMed, Embase, and the Cochrane Library, incorporating RCTs comparing CRT combined with consolidative ICIs versus CRT alone, or CRT with both concurrent and consolidative ICIs versus CRT alone. The primary outcomes were overall survival (OS) and progression-free survival (PFS). To reduce potential bias, an additional mirror-design analysis was performed through network meta-analysis. A total of 13 RCTs comprising 6868 patients and 14 cohort studies comprising 4724 patients were included. While patients treated with CRT and consolidative ICIs demonstrated significantly superior OS and PFS to patients treated with CRT alone in RCTs (HR of OS, 0.743, 95% CI, 0.654-0.843; HR of PFS, 0.674, 95% CI, 0.577-0.786), CRT and concurrent-plus-consolidative ICIs did not improve OS and PFS compared with CRT alone (HR of OS, 0.942, 95% CI, 0.782-1.134; HR of PFS, 0.880, 95% CI, 0.752-1.030). Significant differences were detected in OS (p = 0.038) and PFS (p = 0.017) between CRT combined with consolidative ICIs treatment versus CRT combined with concurrent and consolidative ICIs treatment from RCTs. In conclusion, adding concurrent ICIs may dampen the survival benefits of CRT combined with consolidative ICIs. This evidence informs future RCT design strategies.