Cost-effectiveness analysis of ribociclib plus letrozole versus letrozole monotherapy in postmenopausal women with locally advanced or metastatic HR+/HER2- breast cancer in Vietnam from third-party payer perspective

Tóm tắt/Abstract

To evaluate the cost-effectiveness of ribociclib plus letrozole compared with letrozole monotherapy in the treatment of postmenopausal women with locally advanced or metastatic HR+/HER2− breast cancer in Vietnam. A cost–utility analysis was conducted using a three-state partitioned survival model consisting of progression-free, progressed disease, and death states. The model adopted a lifetime horizon of 40 years with one-month cycles, from the third-party payer perspective. Clinical efficacy and utility parameters were derived from pivotal clinical trials and supplemented by published literature. Costs were estimated based on local price data and health resource utilization. Compared with letrozole monotherapy, ribociclib plus letrozole produced gains of 1.44 life-years and 1.31 quality-adjusted life-years (QALYs), at an additional cost of 535 million VND. The incremental cost-effectiveness ratio (ICER) was 370 million VND per life-year gained and 408 million VND per QALY gained, both of which exceeded the Vietnamese willingness-to-pay (WTP) threshold of one to three times GDP per capita. In reimbursement scenarios, the ICER decreased substantially and fell below the WTP threshold across all evaluated reimbursement levels, indicating that the combination therapy may be considered cost-effective when reimbursement is provided. One-way sensitivity analyses identified the acquisition cost of ribociclib, the discount rate, and the analytic time horizon as the most influential drivers of ICER estimates. From the third-party payer perspective, ribociclib plus letrozole was not considered cost-effectivess in the base case analysis but became cost-effective when partially reimbursed by the national health insurance.