Cost-effectiveness analysis of first-line gifitinib plus pemetrexed-platinum-based chemotherapy versus gifitinib monotherapy in EGFR-mutated NSCLC patients with brain metastases

Brain metastases (BrMs) frequently manifest in patients with epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC), and the optimal treatment approach for these individuals remains controversial. This study aimed to evaluate the cost-effectiveness of adding pemetrexed-platinum chemotherapy to first-line gefitinib in EGFR-mutant NSCLC patients with BrMs, considering the perspective of the Chinese healthcare system. Constructing a Markov model, we simulated disease progression over a 10-year horizon in 4-week intervals. The model included three main health states: progression-free survival (PFS), progressive disease (PD), and death, along with a temporary PFS health state. Transition probabilities were estimated based on the data from the GAP BRAIN trial. Costs and utilities were collected from local public database and literature. One-way and probabilistic sensitivity analyses were employed to assess the robustness of the model. In the base case analysis, adding pemetrexed-platinum chemotherapy to first-line gefitinib resulted in an incremental effectiveness of 0.59 quality-adjusted life years (QALYs) and an increase in healthcare costs by $12,298.51. Consequently, the incremental cost-effectiveness ratio (ICER) amounted to $24,887.67/QALY, which fell below the prespecified willingness-to-pay (WTP) threshold of $37,654.50 per QALY. Deterministic sensitivity analysis indicated that, apart from the utility value of the PFS health state of the gefitinib plus chemotherapy (GPP) group, other parameters exerted minimal influence on the results. The probabilistic sensitivity analysis demonstrated that, at the predefined WTP threshold, the combination of gefitinib and chemotherapy was a cost-effective treatment strategy. Adding pemetrexed-platinum chemotherapy to first-line gefitinib for EGFR-mutant NSCLC patients with BrMs in China represented a cost-effective treatment strategy from the perspective of the Chinese healthcare system.