Occurrence of irAEs after Immune Checkpoint Inhibitor Rechallenge: An Updated Meta-Analysis

What Is Known? and Objective. Immune checkpoint inhibitors (ICIs) play an important role in various cancers. The efficacy and safety of rechallenge with ICIs after immune-related adverse events (irAEs) were not well known. Accumulating studies report inconsistent findings. Thus, we conducted an updated meta-analysis by including more studies. Methods. We searched PubMed, Web of Science, Embase, and Cochrane Library for studies reporting the rechallenge of ICIs after irAEs. The evaluation outcomes included the incidence of irAEs, objective response rate (ORR), and disease control rate (DCR). Results and Discussion. A total of 896 ICI rechallenge cases from 24 studies were included. Compared to the initial treatment with ICIs, rechallenge showed a higher incidence of all-grade irAEs (OR, 2.78; 95% CI, 1.51–5.10; $p=0.001$ ) and high-grade irAEs (OR, 1.88; 95% CI, 1.27–2.78; $p=0.002$ ), but ORR (OR, 1.01; 95% CI, 0.55–1.84; $p=0.97$ ) and DCR (OR, 1.21; 95% CI, 0.68–2.15; $p=0.52$ ) were not further improved after the rechallenge of ICIs. What Is New? and Conclusion. More studies are included in this paper to compare and analyze the efficacy and safety of ICIs after rechallenge, so as to update the previous meta-analyses, and finally get different conclusions from the previous meta-analyses in terms of safety. Our results suggest that rechallenged ICIs after irAEs showed similar efficacy and lower safety than initial ICIs. However, these results need to be further verified by high-quality studies with large samples. In addition, we added subgroup analysis not available in previous meta-analyses to explore the association of cancer type, age, and gender factors with the incidence of irAE after ICI rechallenge.