Trastuzumab Deruxtecan and Sacituzumab Govitecan for Hormone Receptor-Positive and Human Epidermal Growth Factor Receptor 2-Low Metastatic Breast Cancer: A Cost-Effectiveness Analysis

Abstract

Objective: We aim to analyze the pharmacoeconomic characteristics of trastuzumab deruxtecan (T-DXd) and sacituzumab govitecan (SG) in the treatment of patients with hormone receptor-positive (HR+) and human epidermal growth factor receptor 2-low (HER2-low) metastatic breast cancer who have previously undergone chemotherapy.

Methods: A cost-effectiveness study was conducted to compare these two treatment options with chemotherapy, respectively, in terms of their economic impact and clinical outcomes from the perspective of the United States payer. A partitioned survival model with a lifetime horizon comprising three distinct states was utilized for the simulation process of patients receiving trastuzumab deruxtecan or sacituzumab govitecan (in the T-DXd or SG group, respectively). The relevant health preference information and cost data were gathered from published articles.

Results: The T-DXd group, when compared to chemotherapy, provided an additional 0.34816 quality-adjusted life years (QALYs). This benefit was associated with an incremental cost of $222,149, resulting in an incremental cost-effectiveness ratio (ICER) of $638.066 per QALY. For the SG group, in comparison to chemotherapy, an extra 0.17469 QALYs were yielded. This gain was accompanied by an incremental cost of $221,830, leading to an ICER of $1,269,849 per QALY. The ICERs for both T-DXd and SG surpass the predetermined willingness-to-pay (WTP) threshold of $150,000 per QALY. The univariate sensitivity analysis revealed that the costs of SG and T-DXd had a certain influence on the results, whereas other variables had minimal impact.

Conclusion: From the perspective of a U.S. payer, at a willingness-to-pay (WTP) threshold of $150,000 per QALY, both T-DXd and SG were unlikely to be cost-effective compared to chemotherapy for HR+ and HER2-low metastatic breast cancer patients who have previously undergone chemotherapy. However, relative to SG, T-DXd achieved greater QALYs without a significant increase in cost.

Keywords: Breast cancer; Cost-effectiveness; Partitioned survival model; Sacituzumab govitecan; Trastuzumab deruxtecan.