First-line treatment with zolbetuximab plus CAPOX for ClDN18.2-positive gastric or gastroesophageal junction adenocarcinoma: a cost-effectiveness analysis.

BACKGROUND

Patients with HER2-negative locally advanced or unresectable metastatic gastric cancer and gastroesophageal junction (G/GEJ) adenocarcinoma have limited first-line treatment options and a poor prognosis. The GLOW clinical trial showed that zolbetuximab plus capecitabine plus oxaliplatin (CAPOX) significantly prolonged these patients' overall survival (OS) and progression-free survival (PFS).

OBJECTIVES

This study evaluated the cost-effectiveness of zolbetuximab plus CAPOX as a first-line treatment for HER2-negative locally advanced or unresectable metastatic G/GEJ adenocarcinoma in the United States and China.

DESIGN

The cost-effective analysis.

METHODS

Based on the GLOW clinical trial data (NCT03653507), we constructed a 10-year Markov model to assess the cost-effectiveness of the zolbetuximab or placebo plus CAPOX treatment regimen. Only direct medical costs were considered. The primary outcomes of the model were quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratios (ICERs). One-way and probabilistic sensitivity analyses were employed to assess the robustness of the model.

RESULTS

In the United States, zolbetuximab plus CAPOX added 0.24 QALYs and resulted in an incremental cost of $196,791.11 compared with placebo plus CAPOX, which had an ICER of $821,515.65 per QALY gained. For China, the zolbetuximab group gained 0.23 QALYs at an incremental cost of $62,822.69, resulting in an ICER of $273,568.01/QALY. One-way sensitivity analysis revealed that the results were most sensitive to the price of zolbetuximab. Zolbetuximab plus CAPOX had 0% cost-effectiveness at the willingness-to-pay thresholds of $150,000/QALY in the United States and $38,188/QALY in China.

CONCLUSION

Zolbetuximab plus CAPOX may be a cost-effective option for patients with locally advanced, unresectable, or metastatic G/GEJ adenocarcinoma when the price of zolbetuximab reduced by 83.37% ($367.7/100 mg) in the United States and 82.25% ($110.8/100 mg) in China.