OBJECTIVES

: Advanced or metastatic esophageal cancer (EC) has a poor prognosis with a 5-year survival rate of approximately 5%, thus highlighting the need for efficacious and safe therapies. The KEYNOTE-181 trial showed overall survival improvement with pembrolizumab compared to chemotherapy as a second line treatment in EC; however, the cost effectiveness of this therapy has not been analyzed in this setting. The purpose of this analysis is to assess the cost effectiveness of pembrolizumab compared to standard chemotherapy for advanced EC based on the KEYNOTE-181 trial results.

METHODS

: A partition survival model using the Hoyle and Henle method based on the Kaplan-Meier curves from KEYNOTE-181 trial was used to estimate cost-effectiveness for the populations provided in the study (all, PD-L1 CPS ≥10, and squamous cell carcinoma). Costs and utilities were derived from publicly available literature. Model outcomes were total costs, life-years, quality adjusted life-years (QALYs), and the incremental cost effectiveness ratio (ICER). We used a lifetime time horizon, 3% annual discount rate, and a US healthcare perspective.

RESULTS

: Among all patients pembrolizumab yielded 0.904 life-years, 0.695 QALYs and a total cost of $114,526.67. Compared to chemotherapy, this provided an additional 0.158 life-years, 0.121 QALYs, and an increase of $58,023.10. The ICER for pembrolizumab was $481,405.04 per QALY in all patients, $307,749.93 in patients with a positive PD-L1 biomarker, and $249,807.31 in patients with squamous cell carcinoma. A one-way sensitivity analysis showed that the cost pembrolizumab had the largest effect on the ICER.

CONCLUSIONS

: The results of the partition survival model for all three patient populations showed that there was improvement in both life-years and QALYs for pembrolizumab when compared to chemotherapy in the treatment of advanced EC. Thresholds for cost-effectiveness have not been established in the US, but the results here are similar to other end of life oncology therapies.