Pharmacoeconomic Evaluation Of Camrelizumab Plus Chemotherapy In First-line Treatment Of Advanced Non-squamous Non-small-cell Lung Cancer

Objective: Lung cancer is the most common malignant disease all over the world.A clinical trial named Came L has demonstrated the efficacy and safety of camrelizumab combined with chemotherapy in first-line treatment of advanced non-squamous non-small-cell lung cancer without mutations of EGFR and translocations of ALK compared with chemotherapy,but its economic outcomes is not clear yet.In this study,we used cost-utility analysis to evaluate the economic outcomes of camrelizumab combined with chemotherapy compared with chemotherapy alone in the first-line treatment of advanced non-squamous non-small-cell lung cancer without EGFR and ALK alteration from the perspective of Chinese health care system,in order to promote the rational of the drug used in clinical practice and provided the reference basis for evidence-based decision-making of medical insurance.Methods:1.Three pharmacoeconomic evaluation models were constructed by using clinical trial data and relevant literatures data,which were non-homogeneous Markov model for calculating transition probability after re-fitting with existing survival curves,non-homogeneous Markov model for calculating transition probability by using the latest published overall survival data and partitioned survival model.The cycle length of each model was 3 weeks,and the time horizon of the three models were 20 years.2.A total of 15 scenarios were set up based on the possible price level of camrelizumab(currently bid-winning price,price reduced 60% and price reduced 85%)and whether patient assistance program was provided in combination with three different pharmacoeconomic evaluation models.Under the each scenario,the model output indicators were costs,life years and quality-adjusted life years,and the model evaluation indicators were incremental cost-utility ratio,in which the costs and quality-adjusted life years were discounted using a discount rate of 5%,and the economic outcomes of the two regimens were judged by comparing the incremental cost-utility ratio with the willingness-to-pay threshold for pharmacoeconomic evaluation in China(1-3 times per capita GDP in China in 2019).3.One-way sensitivity analyses and probabilistic sensitivity analyses were conducted to evaluate the effect of changes in parameters on the stability of model results.Results:1.In all possible scenarios,camrelizumab combined with chemotherapy regimen could bring more health benefits,but at the same time the cost was high;2.When the model was non-homogeneous Markov model for calculating transition probability by using the latest published overall survival data,compared with the other two models,camrelizumab combined with chemotherapy could bring more health benefits;3.The results of base-case analysis showed that in scenario 1-scenario 15,the incremental cost-utility ratios of camrelizumab combined with chemotherapy compared with chemotherapy were 11,33651 CNY/QALY,3,996,60.28 CNY/QALY,5,70,180.79 CNY/QALY,9,3830.69 CNY/QALY,15,7775.88 CNY/QALY,8,17207.82 CNY/QALY,35,1291.00 CNY/QALY,459,532.62 CNY/QALY,15,7158.99 CNY/QALY,19,7749.60 CNY/QALY,11,8048.73 CNY/QALY,40,215.54 CNY/QALY,56,9305.46 CNY/QALY,9,6951.71 CNY/QALY,and16,360.43 CNY/QALY,respectively.In scenario 4,scenario 5,scenario 9,scenario 10,scenario 14,and scenario 15,the incremental cost-utility ratio of camrelizumab combined with chemotherapy compared with chemotherapy is less than the willingness-to-pay threshold for pharmacoeconomic evaluation in China;4.The results of one-way sensitivity analyses showed that the utility value of progression-free survival status and the proportion of patients received subsequent immunotherapy in the chemotherapy group were the main drivers of the model outcomes in each scenario;the results of probabilistic sensitivity analysis showed that in scenario 1-scenario 15,when the willingness-to-pay threshold was 3 times the GDP per capita in China in2019,the probability of camrelizumab combined with chemotherapy to be cost-effective as first-line treatment for advanced non-squamous non-small-cell lung cancer were 0%,16%,4%,75%,63%,0%,15%,3%,66%,57%,0%,16%,4%,73%,and 61%,respectively.Conclusions:1.When the price of camrelizumab was decreased by 85% to enter the health insurance,camrelizumab combined with chemotherapy was likely to be cost-effective compared with chemotherapy alone as the first-line treatment for advanced non-squamous non-small-cell lung cancer without mutations of EGFR and translocations of ALK.2.We should timely update the pharmacoeconomic evaluation results according to the updated survival data and other relevant data to generate more time-efficient pharmacoeconomic evidence,in order to help the rational of the drug used in clinical practice and provide the reference basis for evidence-based decision-making of medical insurance.