OBJECTIVES: Osimertinib is a third-generation, irreversible, oral, EGFR tyrosine kinase inhibitor (TKI) that potently and selectively inhibits EGFR sensitizing mutations and the TKI resistance-conferring EGFR point mutation T790M. It is the standard of care for advanced EGFRm Non‑small Cell Lung Cancer (NSCLC) and was approved for the adjuvant treatment of adult patients with early-stage NSCLC. The aim of this analysis was to assess the cost-effectiveness of adjuvant osimertinib compared to active surveillance in the treatment of patients with resected EGFR mutation‑positive NSCLC, in the Portuguese setting.

METHODS: A five-health-state transition model with time dependency was developed to estimate lifetime costs and survival of resected EGFRm patients treated with adjuvant osimertinib or active surveillance, with/without prior adjuvant chemotherapy, using a Portuguese National Health Service perspective. Transitions between health states were modeled using ADAURA (NCT02511106, DCO1 January-2020) and FLAURA (NCT02296125) trials data, Portuguese life tables, and real-world data (CancerLinQ Discovery). The model used a ‘cure’ assumption: patients remaining disease free for 5 years after treatment completion for resectable disease were considered ‘cured.’ EQ-5D-5L trial data was converted to utilities based on Portuguese tariffs. Healthcare resource utilization estimates were derived from Portuguese literature.

RESULTS: Adjuvant osimertinib treatment was more effective than active surveillance leading to a mean 2.16 additional quality-adjusted life-years (QALYs) (8.53 vs 6.37) per patient. The modeled median percentage of patients alive at 10 years was 63.5% versus 41.3%, respectively. Osimertinib was associated with mean added costs of 30,514€ per patient and a cost/QALY (incremental cost-effectiveness ratio) of 14,130€ versus active surveillance. Model robustness was demonstrated through scenario analyses.

CONCLUSIONS: In this cost-effectiveness assessment designed for the Portuguese setting, adjuvant osimertinib was considered cost-effective compared with active surveillance for patients with completely resected stage IB‒IIIA EGFRm NSCLC. The robustness of the model results was demonstrated with sensitivity analysis.