Cost-effectiveness of lenvatinib plus pembrolizumab as the second-line treatment for advanced endometrial carcinoma

The combination of lenvatinib and pembrolizumab (LP) for advanced or recurrent endometrial carcinoma has demonstrated improved survival in a clinical study and has been endorsed by the European Society for Medical Oncology. However, the LP regimen is currently not covered by Taiwan’s National Health Insurance (NHI). This study aimed to evaluate the cost-effectiveness of LP as a second-line treatment for advanced endometrial carcinoma (aEC) under Taiwan’s NHI. A 3-state partitioned survival model was used to analyze a hypothetical population of patients with aEC over 20 years. The overall and progression-free survival curves were obtained from the updated results of the phase III trial 309/KEYNOTE-775 and extrapolated using a hybrid method. The pricing of the LP was based on the NHI fee schedule for other cancer treatments. Health state utilities and disutilities related to adverse events were obtained from the published literature. The willingness-to-pay (WTP) threshold was three times the GDP per capita in 2022 (NT$2,917,650). Quality-adjusted life-years (QALYs) and costs were discounted at 3%. Scenario analyses included LP price reductions and time horizon adjustments. Deterministic sensitivity, probabilistic sensitivity, and value of information analyses were performed to assess the uncertainty. LP provided an incremental gain of 0.92 QALYs at an incremental cost of NT$2,929,046, resulting in an incremental cost-effectiveness ratio of NT$3,197,177, which exceeded the WTP threshold. The major factors causing uncertainty were the time horizon and cost of the LP. LP is not a cost-effective second-line therapy for aEC unless its price is reduced by more than 20%.