Cost-effectiveness of first-line osimertinib plus chemotherapy versus amivantamab plus lazertinib for advanced <i>EGFR</i> -mutant NSCLC in the US and China.

e23169 Background: The FLAURA2 and MARIPOSA trials established overall survival benefits of osimertinib plus chemotherapy and amivantamab plus lazertinib, respectively, over osimertinib monotherapy in advanced non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) sensitizing mutation. This study aimed to evaluate the cost-effectiveness of osimertinib plus chemotherapy versus amivantamab plus lazertinib from the US and Chinese healthcare perspectives. Methods: A partitioned survival model with 28-day cycles was developed to simulate total costs, life-years, quality-adjusted life-years (QALYs), incremental cost-effectiveness ratio (ICER) over a 10-year time horizon. Clinical efficacy and safety inputs were derived from FLAURA2 and MARIPOSA. An anchored bridging approach with osimertinib monotherapy as the common comparator was applied. Costs and utilities were sourced from public bid-winning databases, local charges and published literature. A scenario analysis incorporated the amivantamab patient assistance program (PAP) in China. One-way and probabilistic sensitivity analyses (OWSA, PSA) assessed model uncertainty. Results: Compared with osimertinib monotherapy, the ICERs for osimertinib plus chemotherapy were $551,944/QALY (US) and $37,965/QALY (China). For amivantamab plus lazertinib, ICERs were $2,186,499/QALY (US) and $291,478/QALY (China). OWSA identified drug prices and utility values as key drivers. PSA indicated that in the US, osimertinib was cost-effective in 100% of simulations at a $150,000/QALY threshold. In China, at a $40,334.05/QALY threshold, osimertinib plus chemotherapy had a 66.1% probability of being cost-effective. The PAP scenario did not alter the conclusion for amivantamab plus lazertinib in China. Conclusions: Osimertinib monotherapy is the cost-effective option for advanced EGFR-mutant NSCLC in the US. In China, osimertinib plus chemotherapy represents the optimal regimen given current pricing. Amivantamab combinations are not cost-effective in either country at commonly accepted willingness-to-pay thresholds.