Cost-Effectiveness Analysis of Atezolizumab versus Platinum-Based Chemotherapy as First-Line Treatment for Patients with Unresectable Advanced Non-small Cell Lung Cancer with PD-L1 Expression Status in Japan.

Background and objectives: Atezolizumab has demonstrated safety and efficacy in patients with metastatic non-small cell lung cancer (NSCLC) in the IMpower110 trial. The aim of this study was to evaluate the cost-effectiveness of atezolizumab as the first-line treatment for patients with unresectable advanced NSCLC, including programmed cell death ligand-1 (PD-L1)-positive probability testing, from the perspective of healthcare costs in Japan.

Methods: A cost-effectiveness analysis model for atezolizumab, including PD-L1-positive probability testing, was used to construct a partitioned survival model with three health states. To assess the robustness, a probabilistic sensitivity analysis (PSA) was conducted. The acceptable probability was defined as the probability of willingness-to-pay (WTP) over the incremental cost-effectiveness ratio (ICER). Multiple repetitions at WTP thresholds were calculated by continuously reducing the atezolizumab price.

Results: The ICER per quality-adjusted life year (QALY) for atezolizumab therapy only for patients with high PD-L1 expression compared to platinum-based chemotherapy for all patients was 31,975,792 yen per QALY. This is higher than the WTP threshold of 15,000,000 yen. If the cost of atezolizumab were reduced to 54% of the original cost (563,917 yen), the strategy of using atezolizumab for patients with high PD-L1 could become more cost-effective.

Conclusions: The results indicated that atezolizumab was not cost-effective compared to platinum-based chemotherapy as a first-line treatment for patients with unresectable advanced NSCLC. However, we suggest that the price of atezolizumab should be reduced to 54% of the original cost to meet the WTP threshold of 15,000,000 yen per QALY.