Cost-effectiveness analysis of Cadonilimab in first-line treatment of advanced HER2-negative gastric cancer or gastroesophageal junction cancer.

Background: Immune checkpoint inhibitors (ICIs), including Pembrolizumab, Nivolumab, Sintilimab, Tislelizumab, and Sugemalimab, have been approved in China as first-line treatments for advanced HER2-negative gastric cancer (GC) and gastroesophageal junction cancer (GEJC). However, the latest COMPASSION 15 study showed that Cadonilimab in combination with chemotherapy provided significant survival benefits. Objective: This study aims to evaluate the cost-effectiveness of Cadonilimab plus chemotherapy versus chemotherapy alone and the ICIs approved in China for first-line treatment of advanced HER2-negative gastric cancer or gastroesophageal junction carcinoma (GC/GEJC) from the perspective of Chinese payers. Design: The cost-effectiveness analysis. Methods: Based on the research data from COMPASSION-15, KEYNOTE-859, CheckMate-649, ORIENT-16, RATIONALE-305, and GEMSTONE-303, we constructed a 15-year Markov model to evaluate the cost and health outcomes of Cadonilimab combined with chemotherapy versus chemotherapy alone and other ICIs in advanced HER2-negative GC and GEJC. This evaluation includes total cost, life years (LYs), quality-adjusted life years (QALYs), and incremental cost-effectiveness ratio (ICER). Results: Cadonilimab produced 0.73 QALYs (1.10 LYs) at a cost of $26,591. It required an additional investment of $17,826 to gain 0.25 QALYs (0.37 LYs), resulting in an ICER of $72,492.29 per QALY compared to chemotherapy alone. In comparison, other ICIs approved in China-Pembrolizumab, Nivolumab, Sintilimab, Tislelizumab, and Sugemalimab-incurred total costs of $11,735, $13,970, $16,346, $10,765, and $14,857, respectively, generating 0.68 QALYs (1.04 LYs), 0.69 QALYs (1.04 LYs), 0.73 QALYs (1.12 LYs), 0.82 QALYs (1.26 LYs), and 0.81 QALYs (1.25 LYs). Sensitivity analysis revealed that the cost of Cadonilimab, the utility value of progressive disease, and the risk of platelet decline in the Cadonilimab group were the most influential factors affecting the model's stability. At a willingness-to-pay threshold of $37,386, Cadonilimab is not a cost-effective option for the first-line treatment of advanced GE/GEJC. Conclusion: Cadonilimab is not a cost-effective option for the first-line treatment of advanced HER2-negative GC/GEJC. In comparison to other ICIs approved in China, Tislelizumab appears to be a more favorable option.