Tandem Dual CAR-T Cells Targeting HER2 and Mesothelin Enhance anti-Tumor Effects in Pancreatic Cancer

The therapeutic application of T cells engineered to express chimeric antigen receptors (CARs) is hindered by the risk of antigen escape in single-target CAR constructs, particularly in the treatment of solid tumors. Pancreatic cancer cells frequently overexpress tumor-associated antigens, such as human epidermal growth factor receptor 2 (HER2) and Mesothelin (Meso). In this study, we therefore investigated the therapeutic effect of tandem dual CAR-T cells co-targeting Her2 and Meso <i>versus</i> single-targeted CAR-T cells in pancreatic cancer models. We constructed a dual CAR by fusing a HER2-binding single-chain variable fragment (ScFv) with a Meso-binding ScFv. The expression levels of CARs and the anti-tumor efficacy of CAR-T cells were systematically compared <i>via in vitro</i> and <i>in vivo</i> experiments. In HER2/Meso co-expressing pancreatic cancer cell lines (AsPC-1 and SW-1990), dual CAR-T cells exhibited superior antitumor activity, accompanied by increased secretion of anti-tumor cytokines (IL-2 and IFN-γ), compare to HER2-specific or Meso-specific single-target CAR-T cells. In a xenograft mouse model, dual CAR-T cells significantly reduced tumor volume and prolonged mouse survival relative to single-target CAR-T cells. Collectively, our findings demonstrated that dual CAR-T cells enhance antitumor cytotoxicity, supporting their potential as a promising therapeutic strategy for Pancreatic Cancer and other solid tumors.