Association of PD-L1 expression and clinical outcomes in ROS1-rearranged advanced non-small cell lung cancer treated with entrectinib.

Background: In patients with advanced ROS1 rearrangement-positive non-small cell lung cancer (NSCLC), the relationship between programmed death ligand 1 (PD-L1) expression and the efficacy of tyrosine kinase inhibitors (TKIs) remains uncertain. In this study, we analyzed the clinical data of patients with advanced NSCLC harboring ROS1 rearrangements treated with entrectinib to investigate the correlation between PD-L1 expression and the efficacy of entrectinib. Methods: This retrospective study enrolled 37 patients with ROS1-rearranged NSCLC diagnosed at Shanghai Chest Hospital between January 2015 and December 2024, who were treated with entrectinib. The objective response rate (ORR), disease control rate (DCR), and progression-free survival (PFS) of entrectinib treatment were evaluated based on the patients' PD-L1 expression status. Results: Among 37 patients with advanced ROS1 rearrangement NSCLC, there were 16 who received entrectinib as first-line therapy, with an ORR of 68.8% (11/16). There was no significant difference in median PFS (mPFS) between PD-L1-negative and PD-L1-positive groups [16.90 months, 95% confidence interval (CI): not estimable (NE)-NE versus 9.53 months, 95% CI: 4.73-NE; P=0.35] for the first line. There were 21 patients who received entrectinib as second-line or later therapy, whose ORR was 38.2% (8/21). PD-L1-positive patients exhibited a mPFS of 9.6 months (95% CI: 3.13-NE), while PD-L1-negative counterparts demonstrated 5.33 months (95% CI: 4.37-NE). No statistically significant difference was observed (P=0.65). Conclusions: This study did not find evidence that baseline PD-L1 expression significantly influences the efficacy of entrectinib in advanced ROS1-rearranged NSCLC patients.