Objective: To evaluate the cost-effectiveness of nivolumab that has recently been approved for sale in China in treatment of chemotherapy-refractory advanced gastric cancer.  
Methods: Using the data obtained from the ATTRACTION-2 trial (330 cases for nivolumab group, and 
163 cases for placebo group), Markov model was created for simulation of the disease development process of chemotherapy-refractory advanced gastric cancer. The costs, life-years (LY) and quality-adjusted life-years (QALY) in each group were analysed, then the incremental cost-effectiveness ratio (ICER) was calculated to evaluate the cost-effectiveness, and subgroup analysis was also performed based on the expression of programmed death-ligand 1 (PD-L1). The variables were further valued by sensitivity analysis to assess the reliability of the model. 
Results: Among PD-L1 positive patients, the overall health output gained in nivolumab group was 0.357 QALY (0.526 LY) at a cost of 221 171 yuan, and in placebo group was 0.251 QALY (0.368 LY) at a cost of 40 866 yuan; the ICER for the nivolumab group compared with placebo group was 1 700 991 yuan/QALY. Among PD-L1 negative patients, the overall health output gained in nivolumab group was 0.545 QALY (0.845 LY) at a cost of 
333 195 yuan, and in placebo group was 0.403 QALY (0.63 LY) at a cost of 90 285 yuan; the ICER for the nivolumab group compared with placebo group was 1 710 634 yuan/QALY. The ICER values of nivolumab treatment were greater than that of willingness-to-pay (178 980 yuan) in both subgroups. The probabilistic sensitivity analysis showed that the possibility of cost-effectiveness of nivolumab was 0. One-way sensitivity analysis indicated that the most influential parameter was the price of nivolumab. 
Conclusion: Nivolumab does not achieve cost-effectiveness compared to placebo for chemotherapy-refractory advanced gastric cancer at current health care environment in China. However, nivolumab can provide a survival benefit to the patients, and its economical effectiveness can be improved by means such as implementing charity care program and medical insurance coverage.