The Vascular Disrupting Agent CA4P Improves the Antitumor Efficacy of CAR-T Cells in Preclinical Models of Solid Human Tumors

Chimeric antigen receptor (CAR) T cell therapy remains relatively ineffective against solid tumors due to inadequate infiltration and in vivo expansion of CAR-T cells. Unlike hematological malignancies, solid tumors have vascular barriers that hinder CAR-T cells from reaching the tumor site. Here, we demonstrated that combretastatin A-4 phosphate (CA4P), a vascular disrupting agent (VDA), can significantly improve the infiltration ability of CAR-T cells in solid tumors as evidenced by elevated levels of IFN-gamma. Moreover, combined treatment with CA4P and CAR-T cells greatly increased the therapeutic efficiency of the CAR-T cells in subcutaneous ovarian cancer mouse xenograft models and patient-derived xenograft (PDX) models of colon and ovarian carcinoma. Our findings highlight CA4P as an effective antitumor agent candidate for combination with CAR-T cells in clinical applications to treat solid tumors.