Pembrolizumab combined with chemotherapy versus placebo combined with chemotherapy for HER2-negative advanced gastric cancer in China: a cost-effectiveness analysis.

Objective: This study aims to conduct a cost-effectiveness analysis of pembrolizumab in combination with chemotherapy for HER2-negative advanced gastric cancer in China.

Methods: A partitioned survival approach model was constructed to simulate the progression of HER2-negative advanced gastric cancer and evaluate the outcomes of different treatment strategies. We calculated incremental cost-effectiveness ratios (ICER) to assess the cost associated with each quality-adjusted life-year (QALY) gained. One-way sensitivity analysis and probabilistic sensitivity analysis were performed to assess robustness and reliability.

Results: The analysis conducted in the base case demonstrated that the ICER associated with pembrolizumab was $177405.83/QALY gained in all population. In the subgroup analysis, it was found that individuals with a PD-L1 CPS ≥ 1 and those with a PD-L1 CPS ≥ 10 had ICERs of $152397.06/QALY and $109534.13/QALY, respectively. All ICER values for both the all population groups and the subgroups exceeded the WTP threshold in China. Our analysis shows the robustness of these results, as they remained consistent when input parameters were varied within a ± 25% range.

Conclusion: The findings of this cost-effectiveness analysis suggest that pembrolizumab in combination with chemotherapy is not a cost-effective treatment option for HER2-negative advanced gastric cancer in China.