Definition

A small-molecule inhibitor of the serine-threonine kinase Aurora B, with potential antineoplastic activity. Upon administration, defosbarasertib specifically binds to and inhibits Aurora kinase B, which disrupts spindle checkpoint functions and chromosome alignment, and results in the disruption of chromosome segregation and cytokinesis. This inhibits cell division and cell proliferation and induces apoptosis in Aurora kinase B-overexpressing tumor cells. Aurora kinase B, a serine/threonine protein kinase that functions in the attachment of the mitotic spindle to the centromere, is overexpressed in a wide variety of cancer cell types.