Cediranib, also known as AZD2171, is a highly potent inhibitor of recombinant KDR tyrosine kinase activity in vitro (IC50 < 1 nM). Inhibitory activity was also observed against the kinase associated with Flt-1 (IC50 = 5 nM), the VEGF-C and VEGF-D receptor Flt-4 (IC50 ≤ 3 nM), recombinant PDGFR-related kinase c-Kit (IC50 = 2 nM), and PDGFRβ tyrosine kinase (IC50 = 5 nM). In HUVEC, it inhibited VEGF-stimulated phosphorylation of KDR, c-Kit, PDGFR-α, PDGFR-β in a dose-dependent manner with IC50 values of 0.5, 1, 5, and 8 nM, respectively. Cediranib exhibits antitumor and antiangiogenic activity, and is a potential treatment for hypertension.