Objectives: Nivolumab, an immune checkpoint inhibitor, was approved by the United States (US) Food and Drug administration as a first-line systemic therapy for locally advanced/metastatic gastric cancer patients. The current study aimed to investigate the cost-effectiveness of nivolumab-chemotherapy combination versus chemotherapy alone as a first-line therapy from a US payer perspective.
Methods: An economic evaluation was conducted using a partitioned survival model in Microsoft Excel® using data from the CheckMate 649 trial. Three discrete mutually exclusive health states (progression-free, post-progression, and death) were included in the model. The health state occupancy was calculated using the overall survival and progression-free survival curves derived from the CheckMate 649 trial. Cost, resource use, and health utility estimates were estimated from a US payer perspective. Deterministic and probabilistic sensitivity analyses assessed the uncertainty of the model parameters.
Results: Nivolumab-chemotherapy provided additional 0.25 life years compared to chemotherapy alone and the quality-adjusted life years (QALYs) were 0.701 and 0.561, respectively, producing a gain of 0.140 QALYs and an incremental cost-effectiveness ratio of $574,072/QALY.
Conclusion: From the US payer perspective, at a willingness to pay threshold of $US150,000/QALY, nivolumab-chemotherapy was not found to be cost-effective as a first-line therapy for locally advanced/metastatic gastric cancer.
Keywords: cost-effectiveness; gastric cancer; metastatic; nivolumab; trial.