Evaluation of Tucatinib in HER2-Positive Breast Cancer Patients With Brain Metastases: A United States-Based Cost-Effectiveness Analysis

To evaluate the cost-effectiveness of tucatinib in human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC) patients with brain metastases (BMs) and the subgroup of active BMs from the United States (US) payer perspective. A 3-state Markov model was developed to compare the cost-effectiveness of 2 regimens in HER2-positive BC patients with BMs: (1) tucatinib, trastuzumab, and capecitabine (TTC); (2) placebo, trastuzumab, and capecitabine (PTC). And subgroup analysis of active BMs was also performed. Lifetime costs, quality-adjusted life years (QALYs), incremental cost-effectiveness ratio (ICER) and incremental net-health benefit (INHB) were estimated. The willingness-to-pay (WTP) threshold was $200,000/QALY. The robustness of the model was tested by sensitivity analyses. Additional scenario analysis was also performed. Compared with PTC, the ICER yielded by TTC was $418,007.01/QALY and the INHB was -1.08 QALYs in patients with BMs. In the subgroup of active BMs, the ICER and the INHB were $324,465.03/QALY and -0.71 QALY, respectively. The results were most sensitive to the cost of tucatinib. Probabilistic sensitivity analyses suggested that the cost-effective probability of TTC was low at the current WTP threshold in the patients with BMs and the subgroup of active BMs. Tucatinib is unlikely to be cost-effective in HER2-positive BC patients with BMs from the US payer perspective but shows better economics in patients with active BMs. Selecting a favorable population, reducing the price of tucatinib or offering appropriate drug assistance policies might be considerable options to optimize the cost-effectiveness of tucatinib. This study developed a three-state Markov model to explore the cost-effectiveness of tucatinib in breast cancer (BC) patients with brain metastases (BMs). The additional using tucatinib is not cost-effective in BC with BMs but shows better economics in the subgroup of active BMs. Selecting a favorable population and reducing the price of tucatinib might optimize the economics of tucatinib.