Costs of Trastuzumab in Combination With Chemotherapy for HER2-Positive Advanced Gastric or Gastroesophageal Junction Cancer: An Economic Evaluation in the Chinese Context

BackgroundAdding trastuzumab to a conventional regimen of chemotherapy can improve survival in patients with human epidermal growth factor receptor 2 (HER2)-positive advanced gastric or gastroesophageal junction (GEJ) cancer, but the economic impact of this practice is unknown.ObjectiveThe purpose of this cost-effectiveness analysis was to estimate the effects of adding trastuzumab to standard chemotherapy in patients with HER2-positive advanced gastric or GEJ cancer on health and economic outcomes in China.MethodsA Markov model was developed to simulate the clinical course of typical patients with HER2-positive advanced gastric or GEJ cancer. Five-year quality-adjusted life-years (QALYs), costs, and incremental cost-effectiveness ratios (ICERs) were estimated. Model inputs were derived from the published literature and government sources. Direct costs were estimated from the perspective of Chinese society. One-way and probabilistic sensitivity analyses were conducted.ResultsOn baseline analysis, the addition of trastuzumab increased cost and QALY by $56,004.30 (year-2010 US $) and 0.18, respectively, relative to conventional chemotherapy, resulting in an ICER of $251,667.10/QALY gained. Probabilistic sensitivity analyses supported that the addition of trastuzumab was not cost-effective. Budgetary impact analysis estimated that the annual increase in fiscal expenditures would be ∼$1 billion. On univariate sensitivity analysis, the median overall survival time for conventional chemotherapy was the most influential factor with respect to the robustness of the model.ConclusionsThe findings from the present analysis suggest that the addition of trastuzumab to conventional chemotherapy might not be cost-effective in patients with HER2-positive advanced gastric or GEJ cancer.