Abstract
OBJECTIVES: This study assessed the cost-effectiveness of nivolumab plus ipilimumab (NIVO+IPI) versus platinum-doublet chemotherapy (chemo) in untreated metastatic non-small cell lung cancer (NSCLC) using mixture-cure modelling, an approach used to analyse immuno-oncology treatments due to their underlying methods depicting delayed but durable response in some patients. METHODS: A mixture-cure economic model was developed from a US third-party payer perspective to assess the lifetime costs and benefits of NIVO+IPI versus chemo using data from Part 1 of the phase III CheckMate 227 trial with 5 years of follow-up. The model consisted of four health states: progression-free without long-term response (non-LTR), progression-free with long-term response (LTR), post-progression, and death. The primary outcomes were the incremental cost per life-year (LY) and quality-adjusted life-year (QALY) gained for NIVO+IPI versus chemo over a patient's lifetime time horizon. Model uncertainty was evaluated using one-way sensitivity analyses and probabilistic sensitivity analysis. RESULTS: NIVO+IPI treatment showed a significant improvement in overall survival versus chemo; mean gain 1.69 LYs and 1.42 QALYs. The majority of the 4.04 LYs accrued by NIVO+IPI were in the LTR state (2.27 years). The incremental cost of NIVO+IPI versus chemo was US$125,321, resulting in an incremental cost/QALY gained of US$88,219. CONCLUSIONS: This study suggests NIVO+IPI may be a cost-effective first-line treatment when compared with chemo in a US setting given a threshold of US$150,000 per QALY. The cost-effectiveness analysis used a mixture-cure approach, which may offer a more appropriate modelling method in immuno-oncology given LTR, by more accurately capturing the potential treatment benefit.