Background: Novel immunotherapy and targeted therapies prolong survival, but are associated with substantial costs for patients with advanced non-small cell lung cancer (NSCLC). Because biomarker results can strongly impact treatment options, we explored the relation between biomarker results and NSCLC treatment costs. Methods: Using the Flatiron Health database, we conducted a retrospective cohort study to investigate the association between biomarker test results and medication costs in patients with newly diagnosed advanced NSCLC between 2011 and 2020. To be included, patients had to receive at least one biomarker testing. Patients with two or more actionable gene alterations, without structured/treatment data, or who participated in clinical trials were excluded. Patients with negative actionable gene alterations and no definitive PD-L1 results served as the reference group. We linked medication records to Medicare Spending by Drug Dashboard to calculate the first-year cost. We applied a coarsened exact matching approach to estimate the cost difference compared to the matched reference group. Results: A total of 32,008 patients with advanced NSCLC were identified. The mean first-year medication costs in the overall cohort increased from $29,283 in 2011 to $46,062 in 2020. The unadjusted mean first-year costs varied substantially, from $27,703 for patients with ALK+ NSCLC to $51,047 for patients with RET+ NSCLC ($34,520 for the reference group; details in Table). After coarsened exact matching, the mean medication costs for patients with MET+, RET+, BRAF+, PD-L1≥1%, or PD-L1<1% advanced NSCLC were significantly higher than that for the reference group, whereas patients with ALK+ or EGFR+ tumor had significantly lower mean medication costs than the reference group. There was no significant difference in costs between patients with NTRK+ or ROS1+ tumor and the reference group. Conclusions: Our economic evaluation found that medication costs for advanced NSCLC increased substantially over time and differed by biomarker status, highlighting the importance of using more accurate cost estimates in cost-effectiveness analysis of novel therapies to guide value-based practices.

*Negative actionable gene alterations.