Cost-effectiveness Analysis of Trastuzumab Emtansine as Second-line Therapy for HER2-Positive Breast Cancer in China

Trastuzumab emtansine (T-DM1) is the standard second-line option for the treatment of patients with human epidermal growth factor receptor-2 (HER2)-positive breast cancer for its superior clinical efficacy in prolonging progression-free survival. The objective of this study was to evaluate the cost effectiveness of T-DM1 from the Chinese healthcare perspective. Capecitabine (Cap), capecitabine + lapatinib (Cap + Lap), capecitabine + trastuzumab (Cap + Tra), capecitabine + trastuzumab + pertuzumab (Cap + Tra + Per) were selected as comparators. A three-state Markov simulation model was performed. The state transition probabilities were estimated based on the results of a published network meta-analysis, and utilities were derived from the published literature. The costs populated in the model were acquired from the local charge or previously published studies. One-way sensitive analysis and probabilistic sensitivity analyses were performed to test the robustness of the results. Compared with Cap, Cap + Lap, Cap + Tra, and Cap + Tra + Per, T-DM1 was estimated to increase the cost by US$109,699.1, $106,019.1, $97,506.3, and $67,121.9, respectively, and yield a gain of 0.544 quality-adjusted life years (QALYs), 0.383 QALYs, 0.367 QALYs, 0.087 QALYs, respectively. Corresponding incremental cost-effectiveness ratios (ICERs) were $201,652.9, $276,812.5, $265,685.0, and $771,516.1 per QALY. The probabilities of T-DM1 as the dominant option were 0% at the willingness-to-pay (WTP) threshold of $31,245.1/QALY. T-DM1, as second-line therapy in the treatment of HER2-positive breast cancer, is not a cost-effective option in China. Given the significant clinical efficacy, an appropriate price reduction of T-DM1 is required to benefit more HER2-positive breast cancer patients.