Cost Effectiveness of Exclusionary EGFR Testing for Taiwanese Patients Newly Diagnosed with Advanced Lung Adenocarcinoma

Background and Objective Approximately half of lung adenocarcinomas in East Asia harbor epidermal growth factor receptor (EGFR) mutations. EGFR testing followed by tissue-based next-generation sequencing (NGS), upfront tissue-based NGS, and complementary NGS approaches have emerged on the front line to guide personalized therapy. We study the cost effectiveness of exclusionary EGFR testing for Taiwanese patients newly diagnosed with advanced lung adenocarcinoma. Methods This economic evaluation was conducted from the perspective of the healthcare sector with a lifetime horizon. Simulated patients were entered into a joint model combining decision trees and partitioned survival models upon diagnosis of advanced lung adenocarcinoma. We compared exclusionary EGFR testing with upfront tissue-based NGS and complementary NGS approaches. The model inputs were derived from regional estimates (prevalence of targetable gene alterations), trials (testing accuracy, survival outcomes, and adverse events), ACT Genomics (testing costs), National Health Insurance payments, retail prices (drug costs), and hospital cohorts (utility values). All costs were made equivalent to 2023 US dollars. An annual discount rate of 3% was applied. We adopted a willingness-to-pay threshold of US$70,000 per quality-adjusted life-year. One-way deterministic and probabilistic analyses were performed. Results The incremental cost-effectiveness ratio of exclusionary EGFR testing versus upfront tissue-based NGS was US$15,521 per quality-adjusted life-year, whereas the incremental net monetary benefit was US$2530. The costs of osimertinib and pembrolizumab were the major determinants. The incremental net monetary benefit of exclusionary EGFR testing versus complementary NGS approach was US$2174, and its major determinants included the true-negative rate of EGFR testing and the prevalence rate of an EGFR mutation. Given the willingness-to-pay thresholds of US$35,000, US$70,000, and US$105,000 (1, 2, and 3 per capita gross domestic product) per quality-adjusted life-year, the probabilities that exclusionary EGFR testing would be cost effective were 79.1%, 95.6%, and 91.2%, respectively. Conclusions Our analysis suggests that exclusionary EGFR testing is a cost-effective strategy for Taiwanese patients newly diagnosed with advanced lung adenocarcinoma.