Ombrabulin is a derivative of CA-4 phosphate. It is known to show antivascular effects through selective disruption of the tubulin cytoskeleton of endothelial cells.
Umbralisib hydrochloride is a novel PI3Kδ inhibitor (IC50 and EC50 of 22.2 nM and 24.3 nM, respectively). Umbralisib hydrochloride is also active against CK1ε (EC50: 6.0 μM).