Abstract 2: T cells selected from lymph node acquisition for adoptive cell therapyin NSCLC

Abstract Background: A primary limitation of PD-1 inhibitors in non-small cell lung cancer (NSCLC) arises from their inability to act on 'cold' tumors without tumor-reactive T cells, necessitating alternative approaches. Adoptive cell therapy (ACT) using (CAR) -engineered cells, strives to enhance antitumor immunity but faces several challenges such as identifying safe antigens, tumor heterogeneity, antigen escape, cell trafficking, and T cell persistence. To address these issues, we explored a new source of T cells from the benign tumor draining lymph nodes (tdLNs) of NSCLC patients. Our initial results have shown that tdLNs is a reservoir for of tumor-relevant 'stem-like' T cells. We posit that employing these pluripotent T cells for ACT could achieve significant tumor rejection in NSCLC. Methods: Resected tumors, tdLN, non-draining (ndLN), and blood from NSCLC patients, as well as a syngeneic murine lung cancer model (344SQ), underwent analysis. T cells were profiled using flow cytometry, cytotoxicity and proliferation assays. TCR and single cell (sc) RNA sequencing assessed clonal expansion, diversity, and transcriptional profiles of tumor-relevant T cells. T cells were then transduced with an ICAM-1 targeting CAR, in vivo efficacy was evaluated in an A549 murine lung cancer model. Results: T cell subsets with stem-cell memory characteristics, as indicated by PD-1+, TCF1hi, CXCR5+, and CD8+ expression, which were not significantly found in the tumor or PB. These T cells exhibited progenitor-like transcriptional signatures, enhanced SELL and TCF-1 expression, fewer exhaustion markers, and superior in vitro proliferation compared to TILs from both a murine lung cancer model and patient-derived tissues. scRNA sequencing, coupled with TCR "tumor matching" (TM) techniques, exposed a rich clonal diversity of tumor-relevant clones within tdLNs, which showcased a broader transcriptional memory profile and distinct CD4+ and CD8+ phenotypes. Upon analyzing the top 100 expanded (n3) TM clones, 47 featured the presence of tdLN-derived T cells, covering progenitor, stem cell-like, and central memory clusters. T cell subsets were then transduced with a CAR targeting ICAM-1—a cell surface protein frequently overexpressed in NSCLC tumors. Manufacturing protocol yielded high transduction efficiency and T cell expansion within two weeks in 6/6 patients, consistent with PB-derived CAR T cells and on par with the optimal dosing requirements of an ICAM-1 CAR Phase I trial (NCT04420754). tdLN-CAR T cells showed potent antitumor efficacy compared to the control in an aggressive NSCLC murine model (Median survival 103d vs 66d; respectively; p=0. 006). Conclusions: This represents the first reported use of T cells from tdLN for genetically engineered ACT. The data indicate that modifying antigen-experienced, stem-like T cells from tdLN with CAR is a promising and efficient method in a NSCLC murine model, warranting further research. Citation Format: Tatiana Delgado Cruz, Yanping Yang, Rachel Honigsberg, Geoffrey Markowitz, Nasser K Altorki, Vivek Mittal, Moonsoo M. Jin, Jonathan Villena-Vargas. T cells selected from lymph node acquisition for adoptive cell therapyin NSCLC abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 2.