Preclinical study of gene-editing strategy to engineer allogeneic EGFR-targeting CAR T-cells with improved efficacy against solid tumors

Chimeric antigen receptor (CAR) T-cells have induced remarkable clinical responses in patients with hematological cancers. However, CAR T-cell therapies against solid tumors have not elicited similar outcomes since immunosuppressive barriers in the tumor microenvironment attenuate anti-tumor activity. A study at Northeastern University (Boston, MA) aimed to engineer allogeneic CAR T-cells resistant to both biochemical (hypoxia-adenosinergic) and immunological (PD-L1 and TGF-β) inhibitory signaling using a adenine base editor and a CRISPR-Cas12b nuclease. The resulting EGFR-targeting CAR T-cell product comprised a combination of six gene edits designed to evade allorejection (B2M, CIITA), prevent graft-versus-host disease (CD3E), and overcome biochemical (ADORA2A) and immunological (PDCD1, TGFBR2) barriers in solid tumor microenvironment of subcutaneously grown EGFR⁺ human long tumor xenografts. This combinatorial genetic disruption enhances CAR T-cell effector function and anti-tumor efficacy leading to improved tumor elimination and survival in xenograft and humanized mouse solid tumor models.