Definition

An orally bioavailable, allosteric, small-molecule inhibitor of Casitas B-lineage lymphoma proto-oncogene-b (CBL-B), with potential immunomodulatory and antineoplastic activities. Upon oral administration, CBL-B inhibitor HST-1011 targets, binds to and inhibits the activity of CBL-B, which may result in immune activation, the infiltration of natural killer (NK) cells and activated CD8+ T cells in the tumor microenvironment (TME), and the inhibition of tumor growth. CBL-B, an E3 ubiquitin ligase expressed in all leukocyte subsets including T cells and NK cells, is a negative regulator of immune activation.