Economic analysis of osimertinib in previously untreated EGFR-mutant advanced non-small cell lung cancer in Canada.

INTRODUCTION: Osimertinib improves progression-free survival in previously untreated EGFR-positive advanced non-small cell lung cancer (NSCLC) patients, with marked intracranial response rates. However, its cost-effectiveness in a publically funded health care system has not been established. We assessed the cost-effectiveness of first-line osimertinib from the public payer perspective in the Canadian health care system. METHODS: A Markov model was developed to project the outcomes and direct medical costs of initial treatment with osimertinib or current standard-of-care (SoC) EGFR TKIs, gefinitib or afatinib, in patients with previously untreated EGFR-mutant advanced NSCLC. Clinical and cost input estimates were informed from the available literature. Model outcomes included costs (in 2018 Canadian dollars), life years (LYs), quality-adjusted life-years (QALYs), and the cost utility of osimertinib compared to SoC EGFR TKI, or incremental cost per QALY gained. RESULTS: Initial treatment with osimertinib was associated with a gain of 0.79 QALY [95% confidence interval (CI), 0.74 to 0.83] at an incremental cost of $176,394 CAD (95% CI, 176,383 to 176,405) vs. SoC EGFR TKI (incremental cost-effectiveness ratio [ICER]: $223,133/QALY gained; 95%CI, 198,144 to 252,805). Osimertinib had a 0% probability of being cost-effective at a willingness-to-pay threshold of $100,000 per QALY. Deterministic sensitivity analysis showed that the cost of osimertinib had the largest impact on ICER results. CONCLUSION: At the current marketed price, first-line osimertinib therapy in patients with advanced EGFR-mutant lung adenocarcinoma is not cost-effective in Canada. Reduction of osimertinib cost, for example by 25%, can significantly improve the cost-effectiveness profile.