Cost-effectiveness analysis of pembrolizumab versus chemotherapy for microsatellite instability-high or mismatch repair-deficient metastatic colorectal cancer.

The aim of this study was to assess the cost-effectiveness of pembrolizumab versus chemotherapy for metastatic colorectal cancer (mCRC) patients with mismatch-repair deficiency or microsatellite instability-high (dMMR/MSI-H) in China. A partitioned survival model was constructed to determine the costs and effects of pembrolizumab and chemotherapy based on KEYNOTE-177 trial outcomes data. Health outcomes were measured in quality-adjusted life years (QALYs) and incremental cost-effectiveness ratios (ICERs). The Chinese health service system perspective was considered. A willing-to-pay threshold was set at 35,832 USD/QALY, which was three times the gross domestic product (GDP) per capita of China in 2021. We examined the robustness of the model in the one-way and probabilistic sensitivity analysis. Pembrolizumab was associated with better health outcomes than chemotherapy (5.30 vs 3.37 QALYs). Compared with chemotherapy, the pembrolizumab strategy yielded an incremental cost of $16 032.57, which resulted in an ICER of $8285 per QALY. The cost of pembrolizumab and chemotherapy had the largest impact on the ICER. The parameters with less influence on the ICER were utility values of the Post-PFS state. Compared to chemotherapy, pembrolizumab had the economic advantage as the first-line treatment of mCRC patients with dMMR/MSI-H in China.