A novel inhibitor of c-Met and VEGF receptor tyrosine kinases with a broad spectrum of in vivo antitumor activities.

The c-Met receptor tyrosine kinase and its ligand, hepatocyte growth factor (HGF), are dysregulated in a wide variety of human cancers and are linked with tumorigenesis and metastatic progression. VEGF also plays a key role in tumor angiogenesis and progression by stimulating the proangiogenic signaling of endothelial cells via activation of VEGF receptor tyrosine kinases (VEGFR). Therefore, inhibiting both HGF/c-Met and VEGF/VEGFR signaling may provide a novel therapeutic approach for treating patients with a broad spectrum of tumors.

Discovery of N-[5-({2-[(cyclopropylcarbonyl)amino]imidazo[1,2-b]pyridazin-6-yl}oxy)-2-methylphenyl]-1,3-dimethyl-1H-pyrazole-5-carboxamide (TAK-593), a highly potent VEGFR2 kinase inhibitor.

Vascular endothelial growth factor (VEGF) plays important roles in tumor angiogenesis, and the inhibition of its signaling pathway is considered an effective therapeutic option for the treatment of cancer. In this study, we describe the design, synthesis, and biological evaluation of 2-acylamino-6-phenoxy-imidazo[1,2-b]pyridazine derivatives. Hybridization of two distinct imidazo[1,2-b]pyridazines 1 and 2, followed by optimization led to the discovery of N-[5-({2-[(cyclopropylcarbonyl)amino]imidazo[1,2-b]pyridazin-6-yl}oxy)-2-methylphenyl]-1,3-dimethyl-1H-pyrazole-5-carboxamide (23a, TAK-593) as a highly potent VEGF receptor 2 kinase inhibitor with an IC50 value of 0.

Structure-based discovery of cellular-active allosteric inhibitors of FAK.

In order to develop potent and selective focal adhesion kinase (FAK) inhibitors, synthetic studies on pyrazolo[4,3-c][2,1]benzothiazines targeted for the FAK allosteric site were carried out. Based on the X-ray structural analysis of the co-crystal of the lead compound, 8-(4-ethylphenyl)-5-methyl-1,5-dihydropyrazolo[4,3-c][2,1]benzothiazine 4,4-dioxide 1 with FAK, we designed and prepared 1,5-dimethyl-1,5-dihydropyrazolo[4,3-c][2,1]benzothiazin derivatives which selectively inhibited kinase activity of FAK without affecting seven other kinases. The optimized compound, N-(4-tert-butylbenzyl)-1,5-dimethyl-1,5-dihydropyrazolo[4,3-c][2,1]benzothiazin-8-amine 4,4-dioxide 30 possessed significant FAK kinase inhibitory activities both in cell-free (IC50=0.

Anti-angiogenic and anti-tumor effects of TAK-593, a potent and selective inhibitor of vascular endothelial growth factor and platelet-derived growth factor receptor tyrosine kinase.

We recently reported that TAK-593, a novel imidazo[1,2-b]pyridazine derivative, is a highly potent and selective inhibitor of the vascular endothelial growth factor (VEGF) and platelet derived growth factor (PDGF) receptor tyrosine kinase families. Moreover, TAK-593 exhibits a uniquely long-acting inhibitory profile towards VEGF receptor 2 (VEGFR2) and PDGF receptor β (PDGFRβ). In this study, we demonstrated that TAK-593 potently inhibits VEGF- and PDGF-stimulated cellular phosphorylation and proliferation of human umbilical vein endothelial cells and human coronary artery smooth muscle cells.

A novel pyrrolo[3, 2-d]pyrimidine derivative, as a vascular endothelial growth factor receptor and platelet-derived growth factor receptor tyrosine kinase inhibitor, shows potent antitumor activity by suppression of tumor angiogenesis.

We recently reported that compound 20d (comp.20d), a novel pyrrolo[3, 2-d]pyrimidine derivative, is a potent and selective inhibitor of tumor angiogenesis-related kinases, including vascular endothelial growth factor receptor (VEGFR) and platelet-derived growth factor receptor (PDGFR). In this study, we show that comp.

N-phenyl-N'-[4-(5H-pyrrolo[3,2-d]pyrimidin-4-yloxy)phenyl]ureas as novel inhibitors of VEGFR and FGFR kinases.

We have recently reported the discovery of pyrrolo[3,2-d]pyrimidine derivatives 1a and 1b as potent triple inhibitors of vascular endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor (PDGFR), and Tie-2 kinases. To identify compounds having strong inhibitory activity against fibroblast growth factor receptor (FGFR) kinase, further modification was conducted using the co-crystal structure analysis of VEGFR2 and 1b. Among the compounds synthesized, urea derivative 11l having a piperazine moiety on the terminal benzene ring showed strong inhibitory activity against FGFR1 kinase as well as VEGFR2 kinase.

Design, synthesis, and evaluation of 5-methyl-4-phenoxy-5H-pyrrolo[3,2-d]pyrimidine derivatives: novel VEGFR2 kinase inhibitors binding to inactive kinase conformation.

We synthesized a series of pyrrolo[3,2-d]pyrimidine derivatives and evaluated their application as type-II inhibitors of vascular endothelial growth factor receptor 2 (VEGFR2) kinase. Incorporation of a diphenylurea moiety at the C4-position of the pyrrolo[3,2-d]pyrimidine core via an oxygen linker resulted in compounds that were potent inhibitors of VEGFR2 kinase. Of these derivatives, compound 20d showed the strongest inhibition of VEGF-stimulated proliferation of human umbilical vein endothelial cells (HUVEC).