Generation of T cell responses against broad KRAS hotspot neoantigens for cell therapy or TCR discovery

Adoptive cell therapy (ACT) with T cells targeting Kirsten rat sarcoma (KRAS) neoantigens can drive anti-tumor immunity but has so far been focused on a small fraction of known KRAS neoantigens. Here, we develop a single process starting from peripheral blood that can prime and expand T cell responses ex vivo to any KRAS neoantigen based on each individual's human leukocyte antigen (HLA) profile. We conducted the process in 20 healthy donors and generated T cell responses to 46 of 47 evaluated neoantigens. We identified and cloned more than 150 KRAS T cell receptors (TCRs), with the strongest TCRs having similar potency to clinically active benchmark TCRs. T cells generated through this process were able to slow tumor growth in vitro and in vivo. The approach could be used as the basis for the development of an ex vivo primed therapeutic or to discover a library of TCRs against a broad range of KRAS neoantigens.