OBJECTIVE: To analyze the cost-effectiveness of pembrolizumab combined with chemotherapy in the first-line treatment of advanced non-small cell lung cancer

so as to provide reference for clinical rational medication.METHODS: Refer to the KEYNOTE-189 test data

a markov model was established and disease process of pembrolizumab combined with chemotherapy and chemotherapy alone in the first-line treatment of advanced non-small cell lung cancer was simulated. The calculation of transition probability referred to the survival data of KEYNOTE-189 test; the calculation of cost parameters referred to trial intervention method and incidences of adverse reactions

the clinical treatment

examination and adverse reaction handling mode of a domestic cancer hospital

and the medical service charging standard; the utility value referred to related literature. The total cost

quality-adjusted life years and incremental cost-effectiveness ratio（ ICER） of the two sets of programs were calculated through the model

and conduct sensitivity analysis on related parameters. RESULTS: The total treatment costs of embrolizumab combined with chemotherapy and chemotherapy alone were respectively 887 517. 18 yuan and 125 620. 78 yuan

the expected life years were respectively 2. 16 years and 1. 19 years

the quality-adjusted life years were respectively 1. 42 years and0. 79 years. The ICER of pembrolizumab combined with chemotherapy compared with chemotherapy alone was1 198 092. 32 yuan/quality-adjusted life year

which was more than 3 times the per capita GDP of China. Results of sensitivity analysis showed that pembrolizumab combined with chemotherapy has the greatest impact on ICRE in the single-cycle treatment cost of PFS stage. CONCLUSIONS: Pembrolizumab combined with chemotherapy is not economical compared with chemotherapy alone in the first-line treatment of advanced non-small cell lung cancer.