anti-VISTA blocking monoclonal antibody

Anti-VISTA blocking monoclonal antibodies are a class of biologics designed to inhibit the V-domain Ig suppressor of T cell activation (VISTA), a negative checkpoint regulator primarily expressed on myeloid cells. VISTA plays a significant role in suppressing T-cell mediated immune responses and is often upregulated in the tumor microenvironment. In acute myeloid leukemia (AML), VISTA is selectively expressed on leukemia stem cells (LSCs) and blasts, where it promotes cell proliferation and survival in a cell-intrinsic manner, as evidenced by impaired growth in immune-deficient mouse models following VISTA knockdown. By blocking VISTA, these antibodies aim to achieve a dual therapeutic effect: reinvigorating the anti-tumor immune response and directly targeting the maintenance of chemotherapy-resistant LSCs. Preclinical studies have shown that VISTA blockade can reduce the colony-forming capacity of AML cells and impair tumor growth in xenograft models while sparing healthy hematopoietic stem cells, highlighting its potential as a targeted therapy for hematological malignancies.