Abstract A050: Enhancing immune checkpoint inhibitor efficacy by targeting neurotrophic receptor tyrosine kinase 1 signaling in immune resistant non-small cell lung cancer patients
Authors: Smith Margaret R , Wang Yuezhu , Dixon Caroline B. , D'Agostino Ralph , Liu Yin , Oliver George C. , Miller Lance D , Topaloglu Umit , Chan Michael D , Farris Micahel , Su Jing , Mileham Kathryn F , Li Wencheng , Grayson Jason M. , Lycan Thomas , Xing Fei 
Published: December 2023

Abstract
Introduction: The FDA’s approval of immune checkpoint inhibitors (ICI) in 2015 drastically changed the survival of late-stage non-small cell lung cancer (NSCLC) patients. However, only about 30% of NSCLC patients respond to treatment, while the other 70% are immune resistant. Through an analysis of 424 NSCLC patients at Atrium Wake Forest, we have identified a loss-of-function mutation in Neurotrophic Receptor Tyrosine Kinase 1 (NTRK1) as a biomarker for response to ICI. We hypothesize that by treating wild-type immune-resistant tumors with Entrectinib, we can mimic the effect of the mutation in NTRK1 and induce immune responses.
Methods: To identify biomarkers, we collected genomic sequencing data and comprehensive clinical characteristics on 424 NSCLC patients who received ICI or chemo-ICI treatment at Atrium Health Wake Forest Baptist. To determine the role of NTRK1 in vivo, we implanted LL/2-scramble (wild-type NTRK1) or LL/2-shNTRK1, which diminished NTRK1, into C57/B6 mice. The animals were injected with either IgG or Anti-PD1. To determine if we could mimic the effect of a mutation in NTRK1, C57/B6 mice were inoculated with LL2-wildtype NTRK1 and treated with either a) IgG, b) Entrectinib, c) Anti-PD-1, or d) Anti-PD-1 + Entrectinib. All in vivo experiments had tumor growth monitored, and a flow cytometry panel was performed at the endpoint to understand the immune responses. Bulk RNA-Sequencing was performed on cell cultures and tumors.
Results: Mice given the LL/2-shNTRK1 responded to Anti-PD-1 treatment and had a significant increase in CD4+ stem-like effector T cells in the spleen and tumor-draining lymph nodes. Animals that were inoculated with the LL/2 cell lines and treated with Anti-PD-1 + Entrectinib also responded. Mice treated with Anti-PD-1 + Entrectinib were found to have a significant increase in CD4+ stem-like effector T cells as well. RNA-Sequencing revealed that in the mutant cell line LL/2-shNTRK1 and LL/2 tumors treated with Anti-PD-1 + Entrectinib, there was a significant upregulation of C3 production.
Conclusion: Our studies demonstrate that the loss of NTRK1 function, through either genetic ablation or enzymatic inhibition combined with Anti-PD-1, provides a potent treatment for immune-resistant NSCLC tumors.
Citation Format: Margaret R Smith, Yuezhu Wang, Caroline B. Dixon, Ralph D'Agostino, Yin Liu, George C. Oliver, Lance D Miller, Umit Topaloglu, Michael D Chan, Micahel Farris, Jing Su, Kathryn F Mileham, Wencheng Li, Jason M. Grayson, Thomas Lycan, Fei Xing. Enhancing immune checkpoint inhibitor efficacy by targeting neurotrophic receptor tyrosine kinase 1 signaling in immune resistant non-small cell lung cancer patients [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor Immunology and Immunotherapy; 2023 Oct 1-4; Toronto, Ontario, Canada. Philadelphia (PA): AACR; Cancer Immunol Res 2023;11(12 Suppl):Abstract nr A050.