Dual-Targeting CAR-NK Cells in Biomarker-Selected Advanced Colorectal Cancer

Colorectal cancer remains a major cause of cancer-related morbidity and mortality. CAR-NK therapy is being explored as a potentially safer, 'off-the-shelf' adoptive cell therapy platform with lower risk of graft-versus-host disease and typically less severe cytokine release than CAR-T in early experiences. Target selection for solid tumors is limited by tumor heterogeneity and on-target/off-tumor expression. To reduce antigen escape and increase tumor selectivity, this study tests dual-target recognition against CRC-associated antigens: CEA (CEACAM5) and GUCY2C (GCC), with a HER2/ERBB2-positive subset as an exploratory population. GUCY2C is frequently retained in primary and metastatic CRC and is a well-established CRC target antigen. HER2 amplification/overexpression occurs in a minority of metastatic CRC and can be identified by validated IHC/ISH or genomic assays. Biomarker assessment and target-pair selection: Tumor tissue (archival or fresh) is tested by central laboratory immunohistochemistry (IHC) for CEA and GUCY2C, and by HER2 testing per colorectal cancer criteria (IHC with reflex amplification testing as needed). Participants must meet co-expression thresholds for one antigen pair and are assigned accordingly. After Part A (dose escalation), a prespecified selection algorithm will nominate the target pair for expansion using a composite score including DLT rate, feasibility/manufacturing success, ORR/DCR signals, CAR-NK persistence, and evidence of target engagement. Treatment plan: Participants receive lymphodepleting chemotherapy followed by infusion of the assigned dual-target CAR-NK cells. A second infusion in the same cycle may be permitted in selected dose levels if safety criteria are met. Hospitalization/close monitoring is required during the early post-infusion period.