Virtual Library

Start Your Search

M. Mayor



Author of

  • +

    MA13 - Modern Technologies and Biological Factors in Radiotherapy (ID 395)

    • Event: WCLC 2016
    • Type: Mini Oral Session
    • Track: Radiotherapy
    • Presentations: 1
    • +

      MA13.07 - Tumor-Targeted Radiation Promotes Abscopal Efficacy of Regionally Administered CAR T Cells: A Rationale for Clinical Trial (ID 5456)

      17:24 - 17:30  |  Author(s): M. Mayor

      • Abstract
      • Presentation
      • Slides

      Background:
      Our laboratory has demonstrated the augmented anti-tumor efficacy of intrapleurally administered cancer-antigen mesothelin (MSLN)-targeted chimeric antigen receptor (CAR) T cells (Sci Transl Med 2014), and translated the approach to a clinical trial (NCT02414269) for thoracic malignancies. We hypothesized that regionally administered MSLN CAR T cells can circulate systemically to achieve abscopal anti-tumor efficacy in an antigen-specific manner, and the abscopal efficacy can further be promoted by tumor-targeted radiation therapy (RT).

      Methods:
      Using optimized protocols that would permit non-necrotic, well-vascularized tumor growth in pleura, chest wall, peritoneum and flank, tumors were established in immunodeficient (NOD/SCID gamma) mice using mesothelioma or lung adenocarcinoma (LAC) cells. Tumor burden progression, MSLN-targeted CAR T-Cell accumulation at primary and distant tumors was monitored by noninvasive bioluminescence imaging (BLI) and tumor volume measurements.

      Results:
      A single dose of MSLN CAR T cells administered intrapleurally proliferated (Figure 1A left panel), circulated extrapleurally and accumulated at abscopal sites, including the lymph nodes, chest wall, peritoneum, and flank within 3-5 days, with subsequent T-cell proliferation at abscopal sites (Figure 1A right panel). Primary tumor-targeted, single-dose, thoracic RT prior to T-cell administration augmented T-cell accumulation as demonstrated by BLI (Figure 1B) and tumor T-cell quantification (p<0.01). In a mouse model of primary pleural, abscopal antigen-expressing and non-expressing flank tumors (Figure 1C), a single, low-dose, non-cytotoxic thoracic RT enhanced abscopal site CAR T-cell accumulation that resulted in tumor regression (p=0.01; Figure 1D). Figure 1



      Conclusion:
      Regionally administered mesothelin-targeted CAR T cells proliferate and eradicate the primary tumor, accumulate and demonstrate anti-tumor efficacy at abscopal sites prior to eradication of the primary tumor in an antigen-specific manner. A single low-dose primary tumor-targeted radiation therapy promotes scopal and abscopal anti-tumor efficacy. These results provide rationale to initiate a clinical trial of combination regional therapies with radiation therapy and CAR T cells.

      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.