Virtual Library

Start Your Search

Navin Chintala



Author of

  • +

    MA11 - Biomarkers of IO Response (ID 912)

    • Event: WCLC 2018
    • Type: Mini Oral Abstract Session
    • Track: Immunooncology
    • Presentations: 1
    • Moderators:
    • Coordinates: 9/25/2018, 10:30 - 12:00, Room 203 BD
    • +

      MA11.01 - Comparative Efficacy of T-Cell Intrinsic Versus Extrinsic PD-1 Blockade to Overcome PD-L1+ Tumor-Mediated Exhaustion (ID 14194)

      10:30 - 10:35  |  Author(s): Navin Chintala

      • Abstract
      • Presentation
      • Slides

      Background

      Anti-PD-1 agents are effective in overcoming PD-L1+ mediated T-cell exhaustion. Effective therapeutic regimens include multiple, long-term administration. We hypothesized that a single dose of T-cell intrinsic PD-1 blockade by expression of a dominant negative receptor (PD1-DNR) can be equally effective as multiple doses of anti-PD-1 agent administration in the treatment of PD-L1 overexpressing thoracic cancers.

      a9ded1e5ce5d75814730bb4caaf49419 Method

      Human T cells engineered to target the cancer-antigen mesothelin (MSLN) by expression of a chimeric antigen receptor (CAR) with or without co-transduction with a PD1-DNR underwent repeated antigen stress with cancer cells with constitutive overexpression of PD-L1. For comparative efficacy evaluation, anti-PD-1 antibody was co-administered with CAR T cells (CARs). In vitro efficacy was evaluated by cytotoxicity (chromium-51 release assay). In vivo, mice with established pleural tumor were treated with either a single dose of MSLN CARs (with and without anti-PD-1 agent) or MSLN PD1-DNR CARs. Tumor burden regression by bioluminescence imaging and median survival were evaluated.

      4c3880bb027f159e801041b1021e88e8 Result

      In vitro, constitutive PD-L1 overexpression (Fig. A) inhibits MSLN CAR effector function as evidenced by a decrease in cytotoxicity following repeated stimulation with MSLN+PD-L1hi tumor cells (Fig B). MSLN PD1-DNR CARs had increased cytotoxicity when compared to MSLN CARs with or without high frequency anti-PD-1 antibody supplementation. In vivo, mice treated with MSLN CAR (with or without anti-PD-1 antibody) or MSLN PD1-DNR CARs demonstrated enhanced tumor regression (Fig C) and prolonged median survival (Fig D) compared to MSLN CARs alone. Furthermore, a single low dose of MSLN PD1-DNR CARs shows equal anti-tumor efficacy compared to MSLN CARs with multiple doses of anti-PD-1 antibody.

      dozier_figure 1.png

      8eea62084ca7e541d918e823422bd82e Conclusion

      Our results demonstrate that CAR T cells engineered to express a cell-intrinsic PD-1 dominant negative receptor overcome PD-L1 mediated T-cell inhibition equally compared to multiple doses of anti-PD-1 antibody administration. A clinical trial with MSLN CAR PD1-DNR CAR T cells is being initiated.

      6f8b794f3246b0c1e1780bb4d4d5dc53

      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.