Cost-effectiveness analysis of adjuvant atezolizumab in stage II-IIIA non-small cell lung cancer expressing ≥50% PD-L1: A United Kingdom health care perspective

Abstract

Objectives: Atezolizumab monotherapy has marketing authorisation by the Medicines and Healthcare products Regulatory Agency as adjuvant treatment following complete resection for adults with stage II-IIIA non-small cell lung cancer (NSCLC) whose tumours have PD-L1 expression on ≥ 50% of tumour cells and whose disease has not progressed following adjuvant platinum-based chemotherapy. This study evaluated the cost-effectiveness of atezolizumab vs best supportive care (BSC) in the licensed patient population from a UK perspective.

Materials and methods: Patient characteristics and clinical inputs were derived from the global, randomised, open-label, phaseIII IMpower010 trial. A Markov model with the following health states was developed: disease-free survival (DFS), locoregional recurrence, first-line metastatic recurrence, second-line metastatic recurrence, and death (all partitioned based on receipt of treatment, excluding death). The base case model used a lifetime time horizon (40 years) and 3.5% discounting annually after the first year. DFS from IMpower010 was analysed with parametric survival models to extrapolate outcomes for time points beyond trial follow-up. The models were adjusted to avoid overestimating results for patients with recurrences in the longer term. Grade ≥ 3 treatment-related adverse events with incidences ≥ 2% were included. Health state utility values were derived from the literature and past NICE appraisals. Sensitivity and scenario analyses assessed uncertainty around assumptions and parameter estimates.

Results: In the base case analysis, atezolizumab therapy resulted in an expected gain of 1.87 quality-adjusted life-years (QALYs) corresponding to an incremental cost-effectiveness ratio of £20,392/QALY for atezolizumab vs BSC, demonstrating cost-effectiveness. Results were most influenced by discount effects and utility in the on-treatment DFS state. Scenario analyses were consistent with the base case results.

Conclusion: Atezolizumab after adjuvant chemotherapy is cost-effective for adults with NSCLC in the UK.

Keywords: Adjuvant treatment; Atezolizumab; Cost-effectiveness; Immunotherapy; Non-small cell lung cancer; PD-L1 expression.