Treatment-related Death in Cancer Patients Treated with Immune Checkpoint Inhibitors: A Systematic Review and Meta-analysis.

ABSTRACT

AIMS: We carried out a meta-analysis to determine the risk of treatment-related death associated with immune checkpoint inhibitor use in cancer patients. MATERIALS AND METHODS: We examined data from the Medline and Google Scholar databases. We also examined original studies and review articles for cross-references. Eligible studies included randomised phase II and phase III trials of patients with cancer treated with ipilimumab, pembrolizumab; nivolumab; tremelimumab and atezolizumab. The authors extracted relevant information on participants, characteristics, treatment-related death and information on the methodology of the studies. RESULTS: After exclusion of ineligible records, 18 clinical trials were included in the analysis. The odds ratio for treatment-related death for CTLA-4 inhibitors (ipilimumab and tremelimumab) was 1.80 (95% confidence interval 1.25, 2.59; P=0.002) and for PD-1/PD-L1 inhibitors (nivolumab, pembrolizumab and atezolizumab) was 0.63 (95% confidence interval 0.31, 1.30; P=0.22). Treated cancer seems to have no effect on the risk of treatment-related death. CONCLUSIONS: Analysis of our data showed that CTLA-4 inhibitors (ipilimumab and tremelimumab) in a higher dose (10 mg/kg) seem to be associated with a higher risk of treatment-related death compared with control regimens, whereas PD-1/PD-L1 inhibitors (nivolumab, pembrolizumab and atezolizumab) do not cause the same risk. Clinicians have to be fully aware of these differential risks and council their patients appropriately.