RESUMEN
INTRODUCTION: The objective of this study was to assess the cost-effectiveness of atezolizumab versus best supportive care (BSC) as adjuvant treatment following resection and platinum-based chemotherapy for patients with stage II-IIIA non-small cell lung cancer (NSCLC) whose tumours have a programmed death-ligand 1 (PD-L1) expression ≥ 50% of tumour cells and excluding those with ALK/EGFR mutations, from a French collective perspective. MATERIAL AND METHODS: A five state Markov model over a 20-year time horizon was considered, including disease-free survival (DFS1) from IMpower010 trial, three progression states (locoregional recurrence, first and second-line metastatic recurrence) and death. Utilities, quality-adjusted life year (QALY) decrements associated to adverse events, costs, resource use, and transition probabilities were considered in the model. These inputs were sourced from IMpower010 trial, literature, and clinical experts' opinion. Model uncertainty was assessed through deterministic, probabilistic sensitivity analyses and scenario analyses. RESULTS: Atezolizumab was associated with a QALY gain of 1.662, mainly driven by additional time spent in the DFS state, and a life-year gain of 2.112 years. The incremental cost-effectiveness ratio (ICER) for atezolizumab versus BSC was 21,348/QALY gained. The sensitivity analyses highlighted that uncertainty within the model had limited impact on results. Changing the DFS survival curves to other plausible distributions produced ICERs below 20,000/QALY. Introducing an increasing proportion of cured patients (91.5%) from year two to year five reduced the ICER to 13,083/QALY, while including a loss of efficacy at year two in the atezolizumab treatment arm increased the ICER to 33,755/QALY. DISCUSSION: Atezolizumab as adjuvant treatment in stage II-IIIA NSCLC resected patients with PDL1 ≥ 50% and without ALK/EGFR mutations has a lower ICER than other oncology drugs in France and a similar ICER to other adjuvant treatment in oncology.
