FP04.02 RATIONALE-307: Updated Biomarker Analysis of Phase 3 Study of Tislelizumab Plus Chemo vs Chemo Alone For 1L Advanced Sq-NSCLC

In the RATIONALE-307 trial (NCT03594747), tislelizumab plus platinum-based chemotherapy significantly improved clinical outcomes vs chemotherapy alone in treatment-naïve advanced squamous non-small cell lung cancer (sq-NSCLC). Previously, we showed superior clinical efficacy of tislelizumab plus chemotherapy vs chemotherapy alone regardless of PD-L1 expression (J Clin Oncol 38:2020[suppl; Abstr 9554]) and blood tumor mutational burden (Ann Oncol 2020;31[4):S754–S840). Here we report the updated biomarker analysis of PD-L1 expression, tissue tumor mutational burden (tTMB) and gene expression profiling (GEP) in baseline tumor samples.