Reinvigoration of innate and adaptive immunity via therapeutic cellular vaccine for patients with AML

Strategies integrating activation of innate and adaptive immunity against cancer are desired. We established a novel platform, Wilms' tumor antigen 1 (WT1)-expressing artificial adjuvant vector cells (aAVC-WT1), linking invariant natural killer T (iNKT)-mediated dendritic cell activation to T cell immunity. Here, we report the first-in-human application of aAVC-WT1 in nine patients with relapsed and refractory acute myelogenous leukemia. No dose-limiting toxicities were observed, whereas activation of iNKT and/or NK cells was observed in all patients. Five patients experienced objective leukemic regression, which correlated with WT1-specific T cell responses. Paired single-cell RNA and T cell receptor (TCR) sequencing demonstrated effector CD8⁺ T cell clones in the bone marrow. Some bone marrow CD8⁺ T cells underwent transition from pre-existing precursor exhausted T cells to functional T cells or emerged as newly activated T cells, some of which were maintained long term. These demonstrate the feasibility and safety of aAVC-WT1 therapy and the capacity of this platform to activate both innate and adaptive immunity in humans.