Chimeric antigen receptor (CAR) cell therapy transforms hematologic cancer treatment but remains limited in solid tumors due to stromal barriers and an immunosuppressive tumor microenvironment that restricts immune cell infiltration. To address these barriers, we develop a cell-free therapeutic platform based on CAR-engineered induced pluripotent stem cell (iPSC)-derived natural killer (NK) extracellular vesicles (CAR-iNEVs), which retain tumor-targeting capability without reliance on live-cell delivery. CAR-iNEV demonstrates potent antitumor activity and excellent tolerability across multiple xenograft and patient-derived models. Mechanistically, CAR-iNEV directly eliminates tumor cells and remodels the tumor microenvironment by promoting pro-inflammatory macrophage polarization, thereby enhancing host innate antitumor immunity. CAR-iNEV also functions cooperatively with immune checkpoint blockade, and combined treatment with CAR-iNEV and CD47 inhibition increases tumor clearance and induces long-term immunological memory in surviving mice. These findings support the therapeutic potential of CAR-iNEV for solid tumors through coordinated tumor targeting and immune microenvironment modulation.
Zhang et al. (Sun,) studied this question.