Preferential tumor targeting of HER2 by iPSC-derived CAR T cells engineered to overcome multiple barriers to solid tumor efficacy

Abstract

Chimeric antigen receptor (CAR) T cell therapies in solid tumors have been limited by on-target, off-tumor toxicity, antigen heterogeneity, and an inability to simultaneously overcome multiple diverse resistance mechanisms within the tumor microenvironment that attenuate anti-tumor activity. Here, we describe an induced pluripotent stem cell (iPSC)-derived CAR T cell that combines a human epidermal growth factor receptor 2 (HER2)-targeting CAR-differentially recognizing tumor from normal cells and enabling detection of both truncated and misfolded HER2-with multiplex editing designed to address and overcome obstacles to maximize efficacy in solid tumor indications. The iPSC-derived, HER2-directed CAR T cells maintained potent HER2-specific anti-tumor activity in both in vitro and in vivo settings, with limited cytolytic targeting of HER2+ normal targets. Combination with therapeutic antibodies enabled comprehensive multi-antigen targeting through both the CAR and a high-affinity, non-cleavable CD16a Fc receptor. Additionally, specific engineering of interleukin (IL)-7R-fusion, transforming growth factor β (TGF-β)-IL-18R, and CXCR2 enabled sustained persistence, resistance to TGF-β-mediated suppression, and specific migration to the tumor.

Keywords: CAR T; HER2; TGF-β; antibody-dependent cellular cytotoxicity; iPSC; solid tumor; trafficking.