Objective To determine whether the first-line treatment using pembrolizumab plus standard chemotherapy of platinum and pemetrexed for patients with metastatic, non-squamous, non–small-cell lung cancer (NSCLC) is cost-effective in China.

Methods We applied partitional survival analysis to assess the cost-effectiveness of pembrolizumab plus the cytotoxic chemotherapy (cisplatin/carboplatin and pemetrexed) in metastatic NSCLC in China. We took into account direct medical costs according to the data derived from the KEYNOTE-189 trial and literature. Incremental cost-effectiveness ratio (ICER) was assessed as per life-year (LY) and per quality-adjusted life-year (QALY), with 3% per year discounted rate of costs and outcomes. In the performance of sensitivity analysis, cost of disease-management, utility-PFS (progression-free survival), utility-PD (progressive disease) and the discount were considered as variables. In scenario analysis, a philanthropic support programme in China was considered. The threshold was set to be $28 106/QALY (corresponding to three times the GDP in China).

Results Treatment with pembrolizumab plus platinum and pemetrexed chemotherapy was estimated to increase cost by $139 168 compared with $73 081 (the cost of treatment with chemotherapy alone), leading to ICER of $80 444/LY and $96 644/QALY. Incremental costs/QALY are $90 419, $91 399 and $109 229 for programmed death ligand-1 TPS (tumour proportion scores) ≥50%, 1%–49% and <1% subgroups, respectively. Sensitivity analysis revealed that the price of pembrolizumab and the cost of disease-management in progressive-disease state were major variables.

Conclusion In patients with metastatic non-squamous NSCLC, pembrolizumab plus standard chemotherapy of platinum and pemetrexed as the first-line treatment is not cost-effective in China, regardless of TPS.