Abstract
OBJECTIVE: To assess the cost-effectiveness of toripalimab plus etoposide and platinum (EP)-based chemotherapy as a first-line treatment for extensive-stage small cell lung cancer (ES-SCLC) from a Chinese healthcare system perspective, and to explore the impact of factors such as biomarker stratification, drug wastage, and drug donation on cost-effectiveness. METHODS: A partitioned survival model was conducted to simulate the disease progression in ES-SCLC patients. Model parameters were derived from the EXTENTORCH clinical trial, public databases, and published literature. Key outcomes included total cost, quality-adjusted life years (QALYs), incremental cost-effectiveness ratio (ICER), and incremental net monetary benefit (INMB). Drug wastage was quantified based on body surface area, and patients were stratified according to biomarkers. Sensitivity analysis and scenario analysis were conducted to assess model stability. RESULTS: Over a 10-year simulation period, the total cost of toripalimab plus EP was $28,551.37, with a QALYs of 0.75; the total cost of EP was $24,678.81, with a QALYs of 0.55. The ICER was $20,034.74/QALY, below China willingness-to-pay threshold of 2-3 times GDP. The sensitivity analysis demonstrated the stability of the conclusions and indicated that when the WTP is set at 2 times the GDP, toripalimab has an 89% probability of being cost-effective. The A11+/B62- genotype and the intratumor heterogeneity (ITH) low population achieve better efficacy and a lower ICER compared to the overall population. While drug wastage increases the treatment cost, it does not alter the conclusions. CONCLUSION: Compared to EP alone, toripalimab plus EP is cost-effective as first-line treatment in Chinese ES-SCLC patients, particularly when considering genetic stratification and donation policies. The study results provide important reference for China medical insurance policy-making and clinical practice.