187P Tissue B-cell Receptor Repertoire As Biomarker of Complete Pathological Response in NSCLC Patients Treated with Neoadjuvant Chemoimmunotherapy (NADIM Trials)

Neoadjuvant chemoimmunotherapy (CI) for potentially resectable stage IIIA NSCLC yields high percentages of complete pathological responses (CPR). However, not all patients achieve CPR, and current biomarkers (PD-L1 and TMB) have limited sensitivity for predicting clinical outcomes. On the other hand, the presence of tertiary lymphoid structures has been associated with better responses to immunotherapy, but the role of B-cells and B-Cell Receptor (BCR) repertoire is largely unknown. Here, using tissue samples from NADIM I and II trials, we analyze the tumoral BCR repertoire and its association with CPR.