Cost-effectiveness analysis of nivolumab plus standard chemotherapy versus chemotherapy alone for the first-line treatment of unresectable advanced or metastatic gastric cancer, gastroesophageal junction cancer, and esophageal adenocarcinoma.

Background Nivolumab plus standard chemotherapy has significant clinical benefits for unresectable advanced or metastatic gastric cancer, gastroesophageal junction cancer, and esophageal adenocarcinoma (GC/GEJC/EAC). However, nivolumab is expensive, necessitating a cost-effectiveness evaluation. Aim This study aimed to evaluate the cost-effectiveness of nivolumab plus standard chemotherapy vs. chemotherapy alone for unresectable advanced or metastatic GC/GEJC/EAC from the Chinese healthcare system perspective. This study was based on randomized clinical trial data from the CheckMate-649 clinical trial (NCT02872116) published in Lancet (June 2021). Method A Markov model was used to assess the cost-effectiveness of nivolumab plus standard chemotherapy versus chemotherapy alone for unresectable advanced or metastatic GC/GEJC/EAC. Drug costs were collected from Tianjin Medical Purchasing Center in 2021, and utility values of health states were obtained from the literature. The reliability of model was assessed with one-way and probabilistic sensitivity analyses. Main outcome measure The main outcomes were costs, quality-adjusted life-years (QALYs) and the incremental cost-effectiveness ratio (ICER). Results Over a 10-year horizon, the outputs were 1.19 QALYs at a cost of $78,814.9 and 0.88 QALYs at a cost of $19,522.3 with nivolumab plus chemotherapy and chemotherapy alone, respectively. The ICER for nivolumab plus chemotherapy versus chemotherapy alone was $191,266/QALY, exceeding the willingness-to-pay (WTP) threshold ($33,436/QALY). One-way sensitivity analysis revealed nivolumab cost was the most influential parameter. Conclusion Adding nivolumab is not cost-effective for unresectable advanced or metastatic GC/GEJC/EAC in the current Chinese healthcare environment.