Adjuvant Chemoradiotherapy for Gastric Cancer: Efficacy and Cost-Effectiveness Analysis

Cost-effectiveness analysis of tislelizumab plus chemotherapy versus placebo plus chemotherapy as first-line treatment for advanced gastric or gastroesophageal junction adenocarcinoma: perspectives from the United States and China

Purpose

The efficacy of tislelizumab plus chemotherapy in improving progression-free survival (PFS) and overall survival (OS) in unresectable gastric or gastroesophageal junction cancer (GC/GEJC) has recently been emphasized. This study compared the cost-effectiveness of tislelizumab plus chemotherapy versus placebo plus chemotherapy for the United States (US) and Chinese populations.

Methods

Using data from the RATIONALE-305 phase 3 trial, a Markov model was developed to analyze quality-adjusted life years (QALYs), incremental cost-effectiveness ratios (ICERs), incremental net health benefits (INHBs), and incremental net monetary benefits (INMBs). The health state utilities and direct medical costs were obtained from the relevant literature and local cost databases. The model uncertainty was evaluated using sensitivity analyses.

Findings

In the base-case analysis, the addition of tislelizumab to chemotherapy yielded an ICER of $37,768.48 per QALY in China, slightly below the willingness-to-pay (WTP) threshold of $38,042.49 per QALY, showing marginal cost-effectiveness with an INHB of 0.05 QALYs and an INMB of $1,852.49. Subgroup analyses revealed ICERs of $23,853.52 for patients with a PD-L1 TAP score ≥ 5% (TAP ≥ 5%). In the US, the ICER was $502,786.22 per QALY in the intent-to-treat (ITT) and $321,395.28 per QALY in the TAP ≥ 5% subgroup, exceeding the US WTP threshold of $150,000.00.

Implications

In China, tislelizumab plus chemotherapy is a cost-effective first-line therapy for unresectable GC/GEJC in both ITT and TAP ≥ 5% subgroups. In the US, tislelizumab plus chemotherapy is not cost-effective.

Cost-effectiveness analysis of pembrolizumab plus chemotherapy versus placebo plus chemotherapy for HER2-negative advanced gastric/gastroesophageal junction cancer in the Chinese healthcare system

BACKGROUND

This study compares first-line pembrolizumab plus chemotherapy with chemotherapy alone for patients with HER2-negative advanced gastric cancer (GC) and gastroesophageal junction cancer (GEJC) in China.

METHODS

A Markov state-transition model was developed based on the phase 3 randomized KEYNOTE-859 clinical trial data. The health state utility values and direct medical costs were derived from the KEYNOTE-859 clinical trial, the relevant literature, and local charges. The measured outcomes included quality-adjusted life-years (QALYs) and the incremental cost-effectiveness ratio (ICER). Probabilistic and one-way sensitivity analyses (OWSA) were performed to assess the uncertainty of the model.

RESULTS

In the base analysis, the incremental effectiveness and cost of pembrolizumab plus chemotherapy versus chemotherapy alone were 0.22 QALYs and $16,627.31, respectively, resulting in an ICER of $76,936.60/QALY, which is higher than the willingness-to-pay threshold in China ($35,864.61/QALY). Subgroup analyses revealed that the ICERs of pembrolizumab plus chemotherapy versus chemotherapy alone were $72,762.68 and $34,813.70 in the populations with PD-L1 CPS of 1 or higher (CPS ≥ 1) and PD-L1 CPS ≥ 10 (CPS ≥ 10), respectively.

CONCLUSIONS

As first-line therapy for patients with locally advanced or metastatic HER2-negative GC/GEJC in China, pembrolizumab plus chemotherapy is less cost-effective than chemotherapy alone, however, in the CPS ≥ 10 subgroup is more.

Locally Advanced Gastric Cancer Management: A Cost-Effectiveness Analysis

Across the nation, patients with locally advanced gastric cancer (LAGC) are managed with modalities including upfront surgery (US) and perioperative chemotherapy (PCT). Preoperative therapies have demonstrated survival benefits over US and thus long-term outcomes are expected to vary between the options. However, as these 2 modalities continue to be regularly employed, we sought to perform a decision analysis comparing the costs and quality-of-life associated with the treatment of patients with LAGC to identify the most cost-effective option. We designed a decision tree model to investigate the survival and costs associated with the most commonly utilized management modalities for LAGC in the United States: US and PCT. The tree described costs and treatment strategies over a 6-month time horizon. Costs were derived from 2022 Medicare reimbursement rates using the third-party payer perspective for physicians and hospitals. Effectiveness was represented using quality-adjusted life-years (QALYs). One-way, two-way, and probabilistic sensitivity analyses were utilized to test the robustness of our findings. PCT was the most cost-effective treatment modality for patients with LAGC over US with a cost of $40,792.16 yielding 3.11 QALYs. US has a cost of $55,575.57 while yielding 3.15 QALYs; the incremental cost-effectiveness ratio (ICER) was $369,585.25. One-way and two-way sensitivity analyses favored PCT in all variations of variables across their standard deviations. Across 100,000 Monte Carlo simulations, 100% of trials favored PCT. In our model simulating patients with LAGC, the most cost-effective treatment strategy was PCT. While US demonstrated improved QALYs over PCT, the associated cost was too great to justify its use.

Cost-Effectiveness of Nivolumab Plus Chemotherapy vs. Chemotherapy as First-Line Treatment for Advanced Gastric Cancer/Gastroesophageal Junction Cancer/Esophagel Adenocarcinoma in China

Objective

The purpose of this study was to evaluate the cost-effectiveness of nivolumab plus chemotherapy vs. chemotherapy as first-line therapy in patients with advanced gastric cancer/gastroesophageal junction cancer/esophageal adenocarcinoma from the perspective of the Chinese healthcare system.

Methods

This economic evaluation used a state-transition Markov model to assess the cost and effectiveness of nivolumab plus chemotherapy vs. chemotherapy as first-line treatment for advanced gastric cancer/gastroesophageal junction cancer/esophageal adenocarcinoma. The characteristics of patients in the model came from a phase 3 open-label randomized clinical trial (CheckMate 649). Key clinical data were based on the CheckMate 649 trial conducted from March 2017 to April 2019, and costs and utilities were collected from the published literature. The total cost of treatment per patient, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio (ICER) were calculated for the two treatment strategies. Deterministic sensitivity analysis and probabilistic sensitivity analysis were performed.

Results

In the baseline analysis, the incremental effectiveness and cost of nivolumab plus chemotherapy vs. chemotherapy were 0.28 QALYs and $78,626.53, resulting in an ICER of $278,658.71/QALY, higher than the willingness-to-pay (WTP) threshold of China ($31,498.70/QALY). The model was sensitive to the duration of progression-free survival (PFS) for the nivolumab plus chemotherapy group, the cost of nivolumab per 100 mg, and the utility of PFS.

Conclusion

Nivolumab plus chemotherapy was clearly not a cost-effective treatment strategy compared with chemotherapy as first-line therapy for patients with advanced gastric cancer/gastroesophageal junction cancer/esophageal adenocarcinoma in China. Reducing the price of nivolumab may improve its cost-effectiveness.

Diffusion kurtosis imaging in the prediction of poor responses of locally advanced gastric cancer to neoadjuvant chemotherapy

PURPOSE

To assess the efficacy of diffusion kurtosis imaging (DKI) in the prediction of the treatment response to neoadjuvant chemotherapy in patients with locally advanced gastric cancer (LAGC).

METHODS

A total of 31 LAGC patients were enrolled in this prospective study. All patients underwent diffusion-weighted MRI examination (with b = 0₁, 200₁, 500₁, 800₂, 1000₄, 1500₄, 2000₆ s/mm², the subscript denotes the number of signal averages) before and after chemotherapy. DKI and mono-exponential (b = 0, 800 s/mm²) models were built. Apparent diffusion coefficient (ADC), mean diffusivity (MD) and mean kurtosis (MK) of the LAGC tumors were measured. The absolute change values (ΔX) and percentage change values (%ΔX) of the above parameters post neoadjuvant chemotherapy (NACT) were calculated. The response was evaluated according to the pathological tumor regression grade scores (effective response group: TRG 0-2, poor response group: TRG 3). Mann-Whitney U test and receiver operating characteristic (ROC) curves were applicated for statistical analysis.

RESULTS

There were 17 patients in the effective response group (ERG), and 14 patients in the poor response group (PRG). The MK_pre and MK_post values in PRG were significantly higher than those in ERG [(0.671 ± 0.026) and (0.641 ± 0.019) vs. (0.584 ± 0.023) and (0.519 ± 0.018), p < 0.001]. ADC_post and MD_post in PRG were significantly lower than those in ERG (p = 0.005, p =0.001). Significant differences were also observed for % ΔMK, ΔMD and ΔMK between the two groups (p < 0.05). The area under the curve (AUC) for the prediction of PRG was highest for MK_post (AUC = 0.958, cutoff value = 0.614). The MK_pre and MK_post had the highest sensitivity (91.70 %) and specificity (93.80 %) in the prediction of PRG, respectively.

CONCLUSION

Both DKI and ADC values show potential for the prediction of the PRG in LAGC patients. The DKI parameters, especially MK_post displayed the best performance.