Cost-effectiveness analysis of immune checkpoint inhibitors versus platinum-based doublet chemotherapy in the first-line treatment of advanced non-small-cell lung cancer with High PD-L1 expression in Japan

BACKGROUND: This study comprehensively evaluated the cost-effectiveness of pembrolizumab, atezolizumab, and nivolumab plus ipilimumab compared with platinum-based doublet chemotherapy as the first-line treatment for advanced NSCLC with PD-L1 TPS ≥ 50% in Japan, incorporating recent Japan-specific clinical trial data and real-world cost estimates from a nationwide administrative database. METHODS: A Markov model was developed to conduct the cost-effectiveness comparison. The model simulated patient transitions between progression-free status, progressed disease, and death over a lifetime horizon using a six-week cycle. Clinical effectiveness data were obtained from pivotal trials, with transition probabilities adjusted using Japanese-specific survival data. Health state utilities were derived from published literature using the EQ-5D questionnaire. Costs were derived from the Diagnosis Procedure Combination database. The analysis was conducted from the Japanese health care payer's perspective, using quality-adjusted life years (QALYs) and incremental cost-effectiveness ratios (ICERs). One-way deterministic and probabilistic sensitivity analyses were performed. RESULTS: Pembrolizumab had the most favorable cost-effectiveness profile, with an ICER of USD 13,423/QALY, well within Japan's willingness-to-pay threshold of USD 35,000/QALY. Nivolumab plus ipilimumab had an ICER of USD 31,150/QALY, whereas atezolizumab had the highest ICER at USD 44,281/QALY. Sensitivity analyses identified key ICER drivers. Results from probabilistic sensitivity analyses were consistent with those of the primary analyses. CONCLUSIONS: Pembrolizumab is a cost-effective first-line treatment for advanced NSCLC with PD-L1 TPS ≥ 50% in Japan. Nivolumab plus ipilimumab is also a viable option. Atezolizumab is the least cost-effective.