Antibody-gamma/delta T cell receptors targeting GPC2 regress neuroblastoma with low antigen density

Chimeric antigen receptor (CAR) T cells have shown promise in hematological cancers but face challenges in solid tumors, partly due to heterogeneous antigen density. Glypican-2 (GPC2) is an oncofetal antigen highly expressed in neuroblastoma and under evaluation in phase 1 clinical trials. Here, we engineer T cells with antibody-T cell receptors (AbTCRs) targeting GPC2. We generate autologous AbTCR T cells using CT3 or humanized CT3 (hCT3) antigen-binding fragments (Fab) linked to γ/δ T cell receptors (TCRs), along with a CD30 co-stimulatory domain. Both CT3 and hCT3 AbTCR T cells show superior antitumor efficacy compared to CT3 CAR T cells, with hCT3 AbTCR T cells inducing significant regression in neuroblastoma with low GPC2 antigen density. Enhanced efficacy is associated with stronger TCR signaling, expansion of stem cell-like memory T cells, and improved CD8+ T cell infiltration. These results highlight the potential of hCT3 AbTCR T cells for neuroblastoma and indicate broad application of AbTCR T cells in solid tumors.