Abstract 6120: Combination of a novel allogeneic anti-cMet CAR-NK cell product with therapeutic antibodies in treating solid tumors

Abstract Both mesenchymal-epithelial transition factor (C-Met) and epidermal growth factor (EGFR) have been acknowledged as significant pan-tumor therapeutic targets. EGFR- and cMet-targeted autologous chimeric antigen receptor (CAR) T therapies have been tested in clinicals. However, the potential toxicity significantly limited their therapeutic outcomes. Compared to T cells, natural killer (NK) cells have a lower risk of inflammatory toxicity and graft-versus-host disease. CAR-NK therapies also can be produced as an off-the shelf product. To prevent antigen escape, we developed cMet targeted NK cells therapy in combination with EGFR targeted therapeutic antibody in treating solid tumors. Our preclinical results demonstrated cMet CAR-NK single treatment or combined with therapeutic antibodies showed better anti-tumor efficacy compared to EGFR/cMet dual-target CAR-NK cells. We verified EGFR and cMet expression in multiple tumor cell lines (HCT116-colon, NUGC4-gastric, and A549/NCI-1975-NSCLC), which were further engineered to express luciferase. EGFR targeted, cMet targeted, and cMet/EGFR dual-targeted CAR structures were designed and transduced with retroviral vectors into expanded NK cells. Flow cytometry was used to compare the transfection rates and phenotyping among different CAR structures. CAR-NK cell functionality was tested using in vitro cytotoxicity assays. In vivo study was performed in subcutaneously inoculated xenografts with intravenous delivery of cryopreserved CAR-NK cells. Flow cytometry analysis revealed efficient transduction in single targeted CARs and dual-targeted tandem CAR (∼80%), but low transduction level in dual-targeted parallel CAR (∼40%). All CAR constructs indicated in vitro specific cytotoxicity using luciferase- and RTCA-based assays. However, compared to dual-targeted CARs, EGFR and cMet single CARs demonstrated significant better tumor regression and NK cell persistence in peripheral blood in an NCI-H1975 s.c. xenograft mouse model. We demonstrated that combination of cMet CAR-NK with EGFR- or EGFR/cMet-targeted therapeutic antibodies resulted in both potent ADCC and CAR activity, whereas EGFR CAR-NK combo showed compromised in vitro tumor killing capacity. Furthermore, cMet CAR-NK solo or combo treatment showed excellent tumor control and survival prolong in different tumor cell line derived xenograft mouse models. These studies have a pivotal role in the evaluation of cMet CAR-NK cell combination therapies against solid tumors and reveal their therapeutic potential. Allogeneic cMet CAR-NK cell therapy and combo may provide safe and effective treatments for pan-tumor patients who have limited therapeutic options. Citation Format: Chao Wang, Tingting Liu, Qin Wang, Yanxue Gong, Fanxiang Gao, Feng Zhou, Zhuoxiao Cao. Combination of a novel allogeneic anti-cMet CAR-NK cell product with therapeutic antibodies in treating solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 6120.