Increased tumor infiltrating lymphocytes (TIL) are associated with improved patient responses to
immunotherapy. As a result, there is interest in enhancing lymphocyte trafficking particularly to
colon cancers since the majority are checkpoint blockade-resistant and microsatellite stable. Here, we demonstrate that activated T-cells (ATC) armed with anti-CD3 x anti-EGFR bispecific antibody increases TIL and mediate anti-
tumor cytotoxicity while decreasing
tumor cell viability. Furthermore, treatment induces endogenous anti-
tumor immunity that resisted
tumor rechallenge and increased memory T-cell subsets in the
tumor. When combined with targeted
tumor expression of the
tumor necrosis factor superfamily member LIGHT, activated T-cell proliferation and infiltration were further enhanced, and human
colorectal tumor regressions were observed. Our data indicate that
tumor-targeted armed bispecific antibody increases TIL trafficking and is a potentially potent strategy that can be paired with combination
immunotherapy to battle microsatellite stable
colon cancer. SIGNIFICANCE: Enhancing trafficking of tumor infiltrating lymphocytes (TILs) to solid
tumors has been shown to improve outcomes. Unfortunately, few strategies have been successful in the clinical setting for solid
tumors, particularly for "cold" microsatellite stable
colon cancers. In order to address this gap in knowledge, this study combined TNFSF14/LIGHT
immunomodulation with a bispecific antibody armed with activated T-cells targeted to the
tumor. This unique T-cell trafficking strategy successfully generated anti-
tumor immunity in a microsatellite stable
colon cancer model, stimulated T-cell infiltration, and holds promise as a combination
immunotherapy for treating advanced and metastatic
colorectal cancer.