A KRASG12V-targeted bispecific T cell engager promotes immunity against colorectal solid tumor

Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations have been detected at high rates in various tumor types, making them one of the most commonly mutated oncogenes. Limited relevant binding pockets have rendered these mutants undruggable for many decades, particularly the KRAS^G12V mutant. Recent advances in T cell receptor (TCR) profiling have provided a new strategy for overcoming this limitation by recognizing neoantigens presented by human lymphocyte antigen (HLA) and inducing T cell-mediated killing responses. Using the previously identified KRAS^G12V-targeting TCR, we engineered bispecific T cell engager receptors (TCERs) with high efficiency and specificity for the KRAS^G12V/HLA-A∗11:01 tetramer. Specifically, TCER01 and TCER02 effectively induced T cell-mediated tumor killing in 2D and 3D <i>in vitro</i> models of solid colorectal tumor cells. The binding and functional assessment of TCER01 and TCER02 exhibited high specificity for the KRAS^G12V 9-mer peptide while showing minimal cross-reactivity to other homologs. TCER01 activity is unique for HLA-A∗11:01, which is distinct from other KRAS^G12V-presenting HLAs. Our study proposes a potential new therapeutic option for KRAS^G12V colorectal cancer and extends our knowledge for developing TCER-based tumor immunotherapies.