Tcr Clonality And Treg Frequency As Predictors Of Outcome In Stage Iii Nsclc Treated With Durvalumab.

3050Background: Novel blood-based biomarkers evaluating T-cell receptor (TCR) clonality as well as the frequency/activation of immune populations hold significant potential for predicting response and elucidating the biology of anti-tumor immunity in stage 3 NSCLC treated with durvalumab. In this study, we sought to characterize clinical and immunologic predictors of durable response to therapy with a specific focus on TCR clonality and peripheral immune populations. Methods: Stage 3 NSCLC patients undergoing chemoradiation (CRT) and durvalumab were prospectively recruited and underwent baseline and serial blood collections. TCR repertoire analysis was performed on cfDNA using hybrid-capture TCR sequencing and TCR diversity estimated using Shannon’s entropy index. Viably preserved peripheral blood mononuclear cells (PBMC) were analyzed by high-dimensional flow cytometry using …