A small molecule tubulin polymerization inhibitor with potential antineoplastic activity. Crolibulin binds to the colchicine-binding site on beta-tubulin and inhibits the polymerization of tubulin into microtubules, which may result in cell cycle arrest, the induction of apoptosis, and the inhibition of tumor cell proliferation. As a vascular disruption agent (VDA), this agent also disrupts tumor neovascularization, which may result in a reduction in tumor blood flow and tumor hypoxia and ischemic necrosis.