CEP-11981 is an orally bioavailable inhibitor of vascular endothelial growth factor receptor (VEGFR) and Tie2 receptor tyrosine kinases with potential antiangiogenic and antineoplastic activities. Preclinical studies have shown that CEP-11981 exhibits promising permeability, metabolic stability, and pharmacokinetic properties across multiple species. Studies of pharmacologic activity across angiogenesis assays, animal tumor models, and human tumor models have shown sustained, dose-related antiangiogenic and antitumor inhibition. In clinical trals CEP-11981 administration leads to disease stabilization in patients with recurrent or refractory solid tumors. Despite acceptable tolerability of CEP-11981 at the MTD, further development by the sponsor has ceased.