Pharmacoeconomic Evaluation of Abemaciclib in Combination with Fulvestrant for Second-line Treatment of Hormone Receptor-positive Advanced Breast Cancer

OBJECTIVE To evaluate the economics of abemaciclib combined with fulvestrant compared with single use of fulvestrant in the second-line treatment of hormone receptor(HR)-positive advanced breast cancer from the perspective of Chinese health-care system. METHODS A partitioned survival model was conducted by using the survival data published from the MONARCH 2 clinical trial and associated cost and utility data. The cycle length of the model was 4 weeks and the time horizon of the model was set to 20 years, the discount rate was 5%. The output indicators of the model were cost and quality-adjusted life year (QALY), and the evaluation indicator of the model was incremental cost-effectiveness ratio(ICER). The willingness-to-pay threshold(WTP) was 1-3 times per capita GDP(￥80 976/QALY-￥242 928/QALY) in China in 2021. Uncertainty analyses were performed to evaluate the robustness of the model results. RESULTS The results of the base-case analyses showed that abemaciclib combined with fulvestrant could bring more health benefits than single use of fulvestrant, but at the same time, the total cost was higher. The incremental QALYs and incremental costs were 0.88 QALYs and ￥306 014.57, respectively, resulting the ICER were ￥348 507.45/QALY. The uncertainty analyses confirmed the robustness of the model results. When the price of abemaciclib reduced 70%, the probability of abemaciclib combined with fulvestrant being cost-effective was more than 50% under the 3 times per capita GDP in China. CONCLUSION Abemaciclib combined with fulvestrant do not have a cost-effective advantage over single use of fulvestrant in second-line treatment of HR-positive advanced breast cancer. However, in more developed regions such as Beijing, Shanghai, abemaciclib combined with fulvestrant has economic advantages.