D-64131 is a novel inhibitor of Tubulin polymerization that competitively binds with [(3)H]colchicine to αβ-Tubulin. D-64131 is cytotoxic and inhibits tumor cell proliferation in vitro (IC50 = 74 nM). D-64131 prevents growth of tumor models in mice following oral administration in vivo. D-64131 has significant potential in cancer treatment.