Virtual Library

Start Your Search

Sha Zhao

Author of

  • +

    MA27 - Novel Drugs and PDX Models (ID 931)

    • Event: WCLC 2018
    • Type: Mini Oral Abstract Session
    • Track: Targeted Therapy
    • Presentations: 1
    • Moderators:
    • Coordinates: 9/26/2018, 13:30 - 15:00, Room 206 BD
    • +

      MA27.10 - EGFR-Targeted Therapy Alters the Tumor Microenvironment In EGFR-Driven Lung Tumors: Rationale for Combination Therapies (ID 11863)

      14:35 - 14:40  |  Author(s): Sha Zhao

      • Abstract
      • Presentation
      • Slides


      Non-small cell lung cancer patients harboring EGFR mutations have significant clinical benefit from EGFR-targeted tyrosine kinase inhibitors (TKIs). However, these patients develop resistance eventually. With the promising implementation of immune checkpoint inhibitors targeting the programmed cell death receptor/ligand 1 (PD-1/PD-L1) pathway for the treatment of lung cancer, there is a growing interest in developing combinatorial therapies that could utilize this immuneapproach in the context of targeted therapies. Although many clinical trials have attempted to study combining EHGR-TKIs with PD-1/PD-L1 inhibitors in NSCLC cases, the clinical benefit is still undefined. Therefore, we carry out this study to investigate the immune response of EGFR-TKIs in EGFR-driven lung tumors, aiming to explore factors may influence the efficacy of this combination strategy.

      a9ded1e5ce5d75814730bb4caaf49419 Method

      We investigated the early and long-term antitumor effects of first-generation TKI gefitinib and third-generation TKI osimertinib respectively in mice with EGFRL858R andEGFR19DEL/T790M-driven lung tumors.The changes of immune texture in tumors were dynamically tested in different treatment groups by flow cytometry and immunohistochemistry.

      4c3880bb027f159e801041b1021e88e8 Result

      Upon treatment of gefitinib and osimertinib, we saw significant tumor regression in mice with TKI-sensitive EGFRL858R lung adenocarcinoma. However, mice with EGFR19DEL/T790M-driven tumors did not respond to gefitinib, but did show a significant tumor response to third-generation TKI osimertinib treatment. Accompanied with obvious tumor shrinkage, we saw a significant increase of infiltrating CD11b+ myeloid cells and CD3+ lymphocytes throughout treatment. We further analyzed subpopulation of CD11b+ myeloid cells and CD3+ lymphocytes. Results showed that EGFR-TKIs may demonstrated anti-tumor activity by raising cytotoxic CD8+ T cells, activating dendritic cells, eradicating Foxp3+ Tregs and inhibiting M2-like polarization at early stage. However, these immune benefits occurred temporarily and gradually disappeared with treatment went on. On the other hands, the proportion of myeloid-derived suppressor cells(MDSCs), particular mononuclear-MDSCs were consistently elevated responding to sensitive EGFR-TKIs treatment.

      8eea62084ca7e541d918e823422bd82e Conclusion

      Together, results of our study provide novel insights into the immune response to EGFR-TKIs in vivo and provides rationale for potential combinations of EGFR-TKIs and immunotherapies for the treatment of lung carcinomas in the early setting, before the establishment of tumor relapse with long-term EGFR inhibition.And additional therapies aiming to eliminate certain immunosuppressive components should be considered when applying this combination strategy.


      Only Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login, select "Add to Cart" and proceed to checkout. If you would like to become a member of IASLC, please click here.

      Only Active Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login or select "Add to Cart" and proceed to checkout.