RESUMEN
The synthesis and biological evaluation of novel Tie-2 kinase inhibitors are presented. Based on the pyrrolopyrimidine chemotype, several new series are described, including the benzimidazole series by linking a benzimidazole to the C5-position of the 4-amino-pyrrolopyrimidine core and the ketophenyl series synthesized by incorporating a ketophenyl group to the C5-position. Medicinal chemistry efforts led to potent Tie-2 inhibitors. Compound 15, a ketophenyl pyrrolopyrimidine urea analog with improved physicochemical properties, demonstrated favorable in vitro attributes as well as dose responsive and robust oral tumor growth inhibition in animal models.
Asunto(s)
Antineoplásicos/síntesis química , Antineoplásicos/farmacología , Descubrimiento de Drogas , Neoplasias/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/farmacología , Pirimidinas/farmacología , Pirroles/farmacología , Receptor TIE-2/antagonistas & inhibidores , Animales , Antineoplásicos/administración & dosificación , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Humanos , Masculino , Estructura Molecular , Neoplasias/enzimología , Neoplasias/patología , Inhibidores de Proteínas Quinasas/administración & dosificación , Pirimidinas/síntesis química , Pirimidinas/química , Pirroles/síntesis química , Pirroles/química , Ratas , Ratas Sprague-Dawley , Receptor TIE-2/metabolismo , Relación Estructura-Actividad , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
The c-Met proto-oncogene is a multifunctional receptor tyrosine kinase that is stimulated by its ligand, hepatocyte growth factor (HGF), to induce cell growth, motility and morphogenesis. Dysregulation of c-Met function, through mutational activation or overexpression, has been observed in many types of cancer and is thought to contribute to tumor growth and metastasis by affecting mitogenesis, invasion, and angiogenesis. We identified human monoclonal antibodies that bind to the extracellular domain of c-Met and inhibit tumor growth by interfering with ligand-dependent c-Met activation. We identified antibodies representing four independent epitope classes that inhibited both ligand binding and ligand-dependent activation of c-Met in A549 cells. In cells, the antibodies antagonized c-Met function by blocking receptor activation and by subsequently inducing downregulation of the receptor, translating to phenotypic effects in soft agar growth and tubular morphogenesis assays. Further characterization of the antibodies in vivo revealed significant inhibition of c-Met activity (≥ 80% lasting for 72-96 h) in excised tumors corresponded to tumor growth inhibition in multiple xenograft tumor models. Several of the antibodies identified inhibited the growth of tumors engineered to overexpress human HGF and human c-Met (S114 NIH 3T3) when grown subcutaneously in athymic mice. Furthermore, lead candidate antibody CE-355621 inhibited the growth of U87MG human glioblastoma and GTL-16 gastric xenografts by up to 98%. The findings support published pre-clinical and clinical data indicating that targeting c-Met with human monoclonal antibodies is a promising therapeutic approach for the treatment of cancer.
Asunto(s)
Anticuerpos Monoclonales/inmunología , Anticuerpos Neutralizantes/inmunología , Proteínas Proto-Oncogénicas c-met/inmunología , Animales , Carcinogénesis/efectos de los fármacos , Carcinogénesis/inmunología , Procesos de Crecimiento Celular/efectos de los fármacos , Factor de Crecimiento de Hepatocito/genética , Factor de Crecimiento de Hepatocito/inmunología , Factor de Crecimiento de Hepatocito/metabolismo , Humanos , Epítopos Inmunodominantes/inmunología , Ratones , Ratones Desnudos , Morfogénesis/efectos de los fármacos , Células 3T3 NIH , Proto-Oncogenes Mas , Proteínas Proto-Oncogénicas c-met/genética , Transgenes/genética , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
The Aurora family of highly related serine/threonine kinases plays a key role in the regulation of mitosis. Aurora1 and Aurora2 play important but distinct roles in the G(2) and M phases of the cell cycle and are essential for proper chromosome segregation and cell division. Overexpression and amplification of Aurora2 have been reported in different tumor types, including breast, colon, pancreatic, ovarian, and gastric cancer. PF-03814735 is a novel, potent, orally bioavailable, reversible inhibitor of both Aurora1 and Aurora2 kinases that is currently in phase I clinical trials for the treatment of advanced solid tumors. In intact cells, the inhibitory activity of PF-03814735 on the Aurora1 and Aurora2 kinases reduces levels of phospho-Aurora1, phosphohistone H3, and phospho-Aurora2. PF-03814735 produces a block in cytokinesis, resulting in inhibition of cell proliferation and the formation of polyploid multinucleated cells. Although PF-03814735 produces significant inhibition of several other protein kinases, the predominant biochemical effects in cellular assays are consistent with inhibition of Aurora kinases. Once-daily oral administration of PF-03814735 to mice bearing human xenograft tumors produces a reduction in phosphohistone H3 in tumors at doses that are tolerable and that result in significant inhibition of tumor growth. The combination of PF-03814735 and docetaxel in xenograft mouse tumor models shows additive tumor growth inhibition. These results support the clinical evaluation of PF-03814735 in cancer patients. Mol Cancer Ther; 9(4); 883-94. (c)2010 AACR.
Asunto(s)
Compuestos Heterocíclicos con 3 Anillos/farmacocinética , Compuestos Heterocíclicos con 3 Anillos/uso terapéutico , Neoplasias/tratamiento farmacológico , Neoplasias/enzimología , Inhibidores de Proteínas Quinasas/farmacocinética , Inhibidores de Proteínas Quinasas/uso terapéutico , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Pirimidinas/farmacocinética , Pirimidinas/uso terapéutico , Administración Oral , Animales , Aurora Quinasas , Disponibilidad Biológica , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Femenino , Compuestos Heterocíclicos con 3 Anillos/administración & dosificación , Compuestos Heterocíclicos con 3 Anillos/farmacología , Histonas/metabolismo , Humanos , Ratones , Ratones Desnudos , Neoplasias/patología , Fosforilación/efectos de los fármacos , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Serina-Treonina Quinasas/metabolismo , Pirimidinas/administración & dosificación , Pirimidinas/farmacología , Especificidad por Sustrato/efectos de los fármacos , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
PURPOSE: The insulin-like growth factor (IGF) signaling pathway is implicated in cellular mitogenesis, angiogenesis, tumor cell survival, and tumorigenesis. Inhibition of this pathway results in decreased cell growth, inhibition of tumor formation in animal models, and increased apoptosis in cells treated with cytotoxic chemotherapy. We generated and characterized a human monoclonal antibody that targeted the IGF receptor. EXPERIMENTAL DESIGN: By use of XenoMouse technology, we generated CP-751,871, a fully human IgG2 antibody with high affinity (K(d) = 1.5 nmol/L) for human IGF-1R and evaluated its biological, pharmacologic, and antitumor properties. RESULTS: This antibody blocks binding of IGF-1 to its receptor (IC(50) 1.8 nmol/L), IGF-1-induced receptor autophosphorylation (IC(50) 0.42 nmol/L) and induced the down-regulation of IGF-1R in vitro and in tumor xenografts. The extent of IGF-1R down-regulation in vivo was proportional to CP-751,871 concentrations in the serum of tumor-bearing mice. Pharmacokinetic profiles in cynomolgus monkeys indicated a close to linear increase of exposure following i.v. dosing of antibody in the range of 3 to 100 mg/kg. CP-751,871 showed significant antitumor activity both as a single agent and in combination with Adriamycin, 5-fluorouracil, or tamoxifen in multiple tumor models. A biomarker assay was developed to establish the relationship between circulating antibody concentrations and down-regulation of IGF-1R in peripheral blood cells. The concentration of CP-751,871 required to down-regulate 50% of IGF-1R on peripheral blood cells was 0.3 nmol/L. CONCLUSION: These data suggest that inhibition of the IGF cascade by use of this monoclonal antibody may be of clinical benefit in the treatment of human cancers.
Asunto(s)
Anticuerpos Monoclonales/inmunología , Neoplasias Colorrectales/patología , Mieloma Múltiple/patología , Receptor IGF Tipo 1/inmunología , Receptor IGF Tipo 1/fisiología , Animales , Antineoplásicos/farmacología , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Modelos Animales de Enfermedad , Regulación hacia Abajo , Inmunoglobulina G/inmunología , Factor I del Crecimiento Similar a la Insulina/metabolismo , Macaca fascicularis , Ratones , Fosforilación , Receptor IGF Tipo 1/biosíntesis , Transducción de Señal , Trasplante Heterólogo , Células Tumorales CultivadasRESUMEN
CP-673,451 is a potent inhibitor of platelet-derived growth factor beta-receptor (PDGFR-beta) kinase- and PDGF-BB-stimulated autophosphorylation of PDGFR-beta in cells (IC(50) = 1 nmol/L) being more than 450-fold selective for PDGFR-beta versus other angiogenic receptors (e.g., vascular endothelial growth factor receptor 2, TIE-2, and fibroblast growth factor receptor 2). Multiple models have been used to evaluate in vivo activity of CP-673,451 and to understand the pharmacology of PDGFR-beta inhibition and the effect on tumor growth. These models include an ex vivo measure of PDGFR-beta phosphorylation in glioblastoma tumors, a sponge model to measure inhibition of angiogenesis, and multiple models of tumor growth inhibition. Inhibition of PDGFR-beta phosphorylation in tumors correlates with plasma and tumor levels of CP-673,451. A dose of 33 mg/kg was adequate to provide >50% inhibition of receptor for 4 hours corresponding to an EC(50) of 120 ng/mL in plasma at C(max). In a sponge angiogenesis model, CP-673,451 inhibited 70% of PDGF-BB-stimulated angiogenesis at a dose of 3 mg/kg (q.d. x 5, p.o., corresponding to 5.5 ng/mL at C(max)). The compound did not inhibit vascular endothelial growth factor- or basic fibroblast growth factor-induced angiogenesis at concentrations which inhibited tumor growth. The antitumor efficacy of CP-673,451 was evaluated in a number of human tumor xenografts grown s.c. in athymic mice, including H460 human lung carcinoma, Colo205 and LS174T human colon carcinomas, and U87MG human glioblastoma multiforme. Once-daily p.o. x 10 days dosing routinely inhibited tumor growth (ED(50) < or = 33 mg/kg). These data show that CP-673,451 is a pharmacologically selective PDGFR inhibitor, inhibits tumor PDGFR-beta phosphorylation, selectively inhibits PDGF-BB-stimulated angiogenesis in vivo, and causes significant tumor growth inhibition in multiple human xenograft models.