Cost-effectiveness analysis of sugemalimab plus chemotherapy for the first-line treatment of advanced gastric cancer or gastroesophageal junction cancer.

The GEMSTONE-303 trial demonstrated the significant efficacy and safety of sugemalimab plus chemotherapy (S + C) as first-line treatment for patients with advanced gastric cancer (GC) or gastroesophageal junction cancer (GEJC). To evaluate the cost-effectiveness of S + C for advanced GC/GEJC from the perspective of the Chinese healthcare system. A partitioned survival model with a 3-week cycle was created to evaluate the cost-effectiveness of S + C compared to placebo plus chemotherapy (P + C) as the first-line treatment for advanced GC/GEJC. Total costs, quality-adjusted life years (QALYs), and incremental cost-effectiveness ratios (ICERs) as the primary outputs. Sensitivity analyses were performed to evaluate the uncertainty and stability of model parameters. Additionally, subgroup and scenario analyses were conducted. The base-case analysis revealed that the total costs of S + C ($89,510.52) was $49,907.43 higher than that P + C ($39,603.10). However, it also increased the QALYs by 0.29 (1.27 QALYs vs. 0.98 QALYs), with an ICER of $170,440.21/QALY, which was higher than the willingness-to-pay of $40,334.05/QALY. Sensitivity analyses demonstrated that the cost of sugemalimab, utility of progression-free survival and the discount rate had a greater impact on the model. Subgroup analyses indicated that S + C was more cost-effective in patients with advanced GC/GEJC with programmed cell death ligand 1 combined positive score ≥10. Compared to P + C, S + C is currently not an economically viable option for first-line treatment of advanced GC/GEJC in China.