CD44v6 as innovative sarcoma target for CAR-redirected CIK cells

Abstract

Purpose of our study was to explore a new immunotherapy for high grade soft tissue sarcomas (STS) based on cytokine-induced killer cells (CIK) redirected with a chimeric antigen receptor (CAR) against the tumor-promoting antigen CD44v6. We aimed at generating bipotential killers, combining the CAR specificity with the intrinsic tumor-killing ability of CIK cells (CAR+.CIK). We set a patient-derived experimental platform. CAR+.CIK were generated by transduction of CIK precursors with a lentiviral vector encoding for anti-CD44v6-CAR. CAR+.CIK were characterized and assessed in vitro against multiple histotypes of patient-derived STS. The anti-sarcoma activity of CAR+.CIK was confirmed in a STS xenograft model. CD44v6 was expressed by 40% (11/27) of patient-derived STS. CAR+.CIK were efficiently expanded from patients (n = 12) and killed multiple histotypes of STS (including autologous targets, n = 4). The killing activity was significantly higher compared with unmodified CIK, especially at low effector/target (E/T) ratios: 98% vs 82% (E/T = 10:1) and 68% vs 26% (1:4), (p<0.0001). Specificity of tumor killing was confirmed by blocking with anti-CD44v6 antibody. CAR+.CIK produced higher amounts of IL6 and IFN-γ compared to control CIK. CAR+.CIK were highly active in mice bearing subcutaneous STS xenografts, with significant delay of tumor growth (p<0.0001) without toxicities.We report first evidence of CAR+.CIK's activity against high grade STS and propose CD44v6 as an innovative target in this setting. CIK are a valuable platform for the translation of CAR-based strategies to challenging field of solid tumors. Our findings support the exploration of CAR+.CIK in clinical trials against high grade STS.

CSPG4-Specific CAR.CIK Lymphocytes as a Novel Therapy for the Treatment of Multiple Soft-Tissue Sarcoma Histotypes

“…We and others studied the use of CAR expressing CIK in STS (32)(33)(34)(35). In our previous study, we demonstrated the preclinical effectiveness of CAR-redirected CIK against CD44v6, which is expressed in about 40% of STS (32).…”

Adoptive immunotherapy with CAR modified T cells in cancer current landscape and future perspectives

“…In mice models, was found an inverse correlation of recovery of NKT cells and GVHD after alloHSCT while preserving a graft-versus-tumor response (200). NKT cells can also be expanded in vitro and can be genetically modified to express CAR (201,202). Thanks to limited TCR alloreactivity and emerging technology to obtain large numbers, NKT cells represent another attractive source to generate off-the-shelf CAR+ immune cells.…”

Chimeric antigen receptor T (CAR-T) cell immunotherapy for sarcomas: From mechanisms to potential clinical applications

“…The in vivo antitumor activity of CD44v6-CAR-CIK cells is also present in subcutaneous xenografts. Significant greater delay of tumor growth in CD44v6-CAR-CIK cell-treated mice was seen compared to untreated and control-treated mice [67]. For these reasons, CD44v6 may be a favorable target for CAR-T cells in future sarcoma clinical trials.…”

“…Recently, CD44v6 was a therapeutic target for CAR-redirected cytokine-induced killer (CIK) T cells for soft tissue sarcoma patients [67]. CD44v6 had an expression average of 40% amongst soft tissue sarcomas such as liposarcoma, fibrosarcoma, leiomyosarcoma, and undifferentiated pleomorphic sarcoma.…”