Page 202 - EJMO-9-1

Eurasian Journal of Medicine and
Oncology
Cost-effectiveness of nivolumab+chemo for gastric/GEJ cancer

In recent years, numerous studies have focused and health policy through a cost-effectiveness analysis
on improving the prognosis for this patient group. At while offering a strong economic rationale for future
present, fluorouracil, platinum compounds, and paclitaxel treatment development directions.
are the primary chemotherapy agents for advanced
G/GEJ/esophageal adenocarcinoma with negative human 2. Methods
epidermal growth factor receptor 2 (HER2) status. 2.1. Population
However, their therapeutic effects are not promising,
as most patients receiving chemotherapy survive for CheckMate 649 is a randomized phase III trial involving
<1 year. Furthermore, the addition of targeted therapy 1,581 patients conducted worldwide from March 2017
4-6
to chemotherapy for these patients has not significantly to April 2019. Our data were derived from clinical
improved survival outcomes compared to chemotherapy characteristics of CheckMate 649 subjects aged 18 years or
alone. 7-10 older with previously untreated and unresectable advanced
or metastatic G/GEJ/esophageal adenocarcinoma, regardless
Nivolumab is a programmed cell death protein 1 (PD-1) of PD-L1 expression.
inhibitor that has gained prominence in tumor therapy due
to the higher expression of programmed cell death ligand 1 We focused on the third phase of the CheckMate
(PD-L1) in tumor cells and tumor-infiltrating immune cells 649 study, which included 955 patients with PD-L1 CPS
compared to normal cells. It has demonstrated significant ≥5. Among these, 473 participants were assigned to the
efficacy in treating various cancers, including non-small cell experimental group (nivolumab plus chemotherapy) and
lung cancer and renal cell carcinoma. 11,12 Consequently, the 482 to the control group (chemotherapy). We conducted
CheckMate 649 phase III trial was conducted, recruiting a cost-effectiveness analysis for both treatment groups to
patients with advanced, unresectable, and HER2-negative provide a foundation for their differing treatment options.
cancers, who were randomly divided into two groups. The research methods adhered to the Consolidated Health
In addition to analyzing all patients, those with PD-L1 Economic Evaluation Reporting Standards guidelines
combined positive score (CPS) ≥5 patients were selected (Table S1).
for follow-up analysis. The prognosis of the two groups 2.2. The model’s structure
was compared: one receiving combination chemotherapy
with nivolumab and the other receiving chemotherapy In this study, we utilized the TreeAge Software 2021
alone. The result indicated that for patients with PD-L1 (TreeAge Software Inc., United States [US]) to develop
CPS ≥5, the median overall survival (OS) improvement a multi-state Markov model assessing the cost-
was 3 months (14.4 months [95% CI: 13.1 – 16.2] vs. effectiveness of nivolumab plus chemotherapy compared
11.1 months [95% CI: 10.0 – 12.1]. The median progression- to chemotherapy alone in patients with untreated and
free survival (PFS) was 7.7 months (95% CI: 7.0 – 9.2) for unresectable advanced or metastatic G/GEJ/esophageal
combination chemotherapy with nivolumab compared adenocarcinoma. The Markov model provided more
to 6.05 months (95% CI: 5.0 – 6.9) for chemotherapy flexible modeling assumptions. It included multiple
14
alone. Among all patients, the median follow-up for OS health states, such as PFS, progressive disease (PD), and
was 13.1 months (interquartile range [IQR]; 6.7 – 19.1) death. Initially, all patients were assumed to be in the PFS
in the nivolumab group versus 11.1 months (IQR: 5.8 – state and received either nivolumab plus chemotherapy
16.1) in the chemotherapy group. The trial concluded that or chemotherapy based on their group assignments. The
nivolumab combined with chemotherapy significantly specific transition relationships are shown in Figure 1. As
improved patient survival compared to chemotherapy the disease progressed, treatment followed the follow-up
alone, particularly in patients with PD-L1 CPS ≥5. 13 treatment plan outlined in the CheckMate 649 clinical trial
until the patient’s death.
A cost-benefit analysis is necessary before a new drug
can be approved as a treatment option for many patients. A Markov model was developed to simulate the entire life
Hence, based on the results of the Checkmate 649 clinical course of patients and evaluate the cost and effectiveness of
trial, we established an economic model to evaluate the first-line therapy for those with advanced or metastatic G/
cost-effectiveness of nivolumab in combination with GEJ/esophageal adenocarcinoma. In the CheckMate 649
chemotherapy in G/GEJ/esophageal adenocarcinoma. clinical trial, the median survival time of the experimental
This study evaluated the pharmacoeconomic value of group was 14.4 months, while the control group had a
this treatment for locally advanced or metastatic G/GEJ/ median survival time of 11.1 months, with an overall
esophageal adenocarcinoma, a treatment regimen not study duration of approximately 2 years. Immunotherapy
fully explored in conventional studies. This study aimed effects are often delayed and may continue to exert benefits
to provide a forward-looking reference for clinical practice beyond the treatment period. Therefore, long-term data

Volume 9 Issue 1 (2025) 194 doi: 10.36922/ejmo.7075