RESUMO
Based on lead compound 1, which was discovered from a high-throughput screen, a series of PI3Kα/mTOR inhibitors were evaluated that contained an imidazo[1,2-a]pyridine as a core replacement for the benzimidazole contained in 1. By exploring various ring systems that occupy the affinity pocket, two fragments containing a methoxypyridine were identified that gave <100 nM potency toward PI3Kα in enzyme and cellular assays with moderate stability in rat and human liver microsomes. With the two methoxypyridine groups selected to occupy the affinity pocket, analogs were prepared with various fragments intended to occupy the ribose pocket of PI3Kα and mTOR. From these analogs, tertiary alcohol 18 was chosen for in vivo pharmacodynamic evaluation based on its potency in the PI3Kα cellular assay, microsomal stability, and in vivo pharmacokinetic properties. In a mouse liver pharmacodynamic assay, compound 18 showed 56% inhibition of HFG-induced AKT (Ser473) phosphorylation at a 30 mg/kg dose.
Assuntos
Inibidores de Fosfoinositídeo-3 Quinase , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Piridinas/química , Serina-Treonina Quinases TOR/antagonistas & inibidores , Animais , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Humanos , Camundongos , Microssomos Hepáticos/química , Microssomos Hepáticos/metabolismo , Modelos Moleculares , Estrutura Molecular , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Proteínas Quinases/síntese química , Ratos , Relação Estrutura-Atividade , Serina-Treonina Quinases TOR/metabolismoRESUMO
Replacement of the piperazine sulfonamide portion of the PI3Kα inhibitor AMG 511 (1) with a range of aliphatic alcohols led to the identification of a truncated gem-dimethylbenzylic alcohol analog, 2-(5-(4-amino-6-methyl-1,3,5-triazin-2-yl)-6-((5-fluoro-6-methoxypyridin-3-yl)amino)pyridin-3-yl)propan-2-ol (7). This compound possessed good in vitro efficacy and pharmacokinetic parameters and demonstrated an EC50 of 239 ng/mL in a mouse liver pharmacodynamic model measuring the inhibition of hepatocyte growth factor (HGF)-induced Akt Ser473 phosphorylation in CD1 nude mice 6 h post-oral dosing.
Assuntos
Álcoois/química , Inibidores de Fosfoinositídeo-3 Quinase , Piperazinas/química , Inibidores de Proteínas Quinases/química , Piridinas/síntese química , Sulfonamidas/química , Triazinas/síntese química , Animais , Feminino , Meia-Vida , Fígado/metabolismo , Masculino , Camundongos , Camundongos Nus , Conformação Molecular , Fosfatidilinositol 3-Quinases/metabolismo , Piperazina , Piperazinas/metabolismo , Piperazinas/farmacocinética , Ligação Proteica , Inibidores de Proteínas Quinases/metabolismo , Inibidores de Proteínas Quinases/farmacocinética , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/metabolismo , Piridinas/metabolismo , Piridinas/farmacocinética , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Relação Estrutura-Atividade , Sulfonamidas/metabolismo , Sulfonamidas/farmacocinética , Serina-Treonina Quinases TOR/antagonistas & inibidores , Serina-Treonina Quinases TOR/metabolismo , Triazinas/metabolismo , Triazinas/farmacocinéticaRESUMO
Tankyrases (TNKS1 and TNKS2) are proteins in the poly ADP-ribose polymerase (PARP) family. They have been shown to directly bind to axin proteins, which negatively regulate the Wnt pathway by promoting ß-catenin degradation. Inhibition of tankyrases may offer a novel approach to the treatment of APC-mutant colorectal cancer. Hit compound 8 was identified as an inhibitor of tankyrases through a combination of substructure searching of the Amgen compound collection based on a minimal binding pharmacophore hypothesis and high-throughput screening. Herein we report the structure- and property-based optimization of compound 8 leading to the identification of more potent and selective tankyrase inhibitors 22 and 49 with improved pharmacokinetic properties in rodents, which are well suited as tool compounds for further in vivo validation studies.
Assuntos
Descoberta de Drogas , Inibidores Enzimáticos/farmacologia , Tanquirases/antagonistas & inibidores , Administração Oral , Disponibilidade Biológica , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/química , Humanos , Modelos Moleculares , Estrutura Molecular , Relação Estrutura-Atividade , Tanquirases/metabolismoRESUMO
Tankyrase (TNKS) is a poly-ADP-ribosylating protein (PARP) whose activity suppresses cellular axin protein levels and elevates ß-catenin concentrations, resulting in increased oncogene expression. The inhibition of tankyrase (TNKS1 and 2) may reduce the levels of ß-catenin-mediated transcription and inhibit tumorigenesis. Compound 1 is a previously described moderately potent tankyrase inhibitor that suffers from poor pharmacokinetic properties. Herein, we describe the utilization of structure-based design and molecular modeling toward novel, potent, and selective tankyrase inhibitors with improved pharmacokinetic properties (39, 40).
Assuntos
Benzimidazóis/síntese química , Oxazolidinonas/síntese química , Tanquirases/antagonistas & inibidores , Administração Oral , Animais , Benzimidazóis/farmacocinética , Benzimidazóis/farmacologia , Sítios de Ligação , Disponibilidade Biológica , Técnicas In Vitro , Camundongos , Microssomos Hepáticos/metabolismo , Modelos Moleculares , Oxazolidinonas/farmacocinética , Oxazolidinonas/farmacologia , Ratos , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
The phosphoinositide 3-kinase family catalyzes the phosphorylation of phosphatidylinositol-4,5-diphosphate to phosphatidylinositol-3,4,5-triphosphate, a secondary messenger which plays a critical role in important cellular functions such as metabolism, cell growth, and cell survival. Our efforts to identify potent, efficacious, and orally available phosphatidylinositol 3-kinase (PI3K) inhibitors as potential cancer therapeutics have resulted in the discovery of 4-(2-((6-methoxypyridin-3-yl)amino)-5-((4-(methylsulfonyl)piperazin-1-yl)methyl)pyridin-3-yl)-6-methyl-1,3,5-triazin-2-amine (1). In this paper, we describe the optimization of compound 1, which led to the design and synthesis of pyridyltriazine 31, a potent pan inhibitor of class I PI3Ks with a superior pharmacokinetic profile. Compound 31 was shown to potently block the targeted PI3K pathway in a mouse liver pharmacodynamic model and inhibit tumor growth in a U87 malignant glioma glioblastoma xenograft model. On the basis of its excellent in vivo efficacy and pharmacokinetic profile, compound 31 was selected for further evaluation as a clinical candidate and was designated AMG 511.
Assuntos
Inibidores de Fosfoinositídeo-3 Quinase , Inibidores de Proteínas Quinases/farmacologia , Triazinas/farmacologia , Cristalografia por Raios X , Modelos Moleculares , Inibidores de Proteínas Quinases/químicaRESUMO
Phosphoinositide 3-kinase (PI3K) is an important target in oncology due to the deregulation of the PI3K/Akt signaling pathway in a wide variety of tumors. A series of 4-amino-6-methyl-1,3,5-triazine sulfonamides were synthesized and evaluated as inhibitors of PI3K. The synthesis, in vitro biological activities, pharmacokinetic and in vivo pharmacodynamic profiling of these compounds are described. The most promising compound from this investigation (compound 3j) was found to be a pan class I PI3K inhibitor with a moderate (>10-fold) selectivity over the mammalian target of rapamycin (mTOR) in the enzyme assay. In a U87 MG cellular assay measuring phosphorylation of Akt, compound 3j displayed low double digit nanomolar IC(50) and exhibited good oral bioavailability in rats (F(oral)=63%). Compound 3j also showed a dose dependent reduction in the phosphorylation of Akt in a U87 tumor pharmacodynamic model with a plasma EC(50)=193 nM (91 ng/mL).
Assuntos
Neoplasias/tratamento farmacológico , Inibidores de Fosfoinositídeo-3 Quinase , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Sulfonamidas/química , Sulfonamidas/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Animais , Antineoplásicos/química , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Sítios de Ligação , Linhagem Celular Tumoral , Cristalografia por Raios X , Feminino , Humanos , Camundongos , Simulação de Acoplamento Molecular , Neoplasias/enzimologia , Neoplasias/metabolismo , Fosfatidilinositol 3-Quinases/química , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacocinética , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Transdução de Sinais/efeitos dos fármacos , Relação Estrutura-Atividade , Sulfonamidas/farmacocinética , Sulfonamidas/uso terapêutico , Serina-Treonina Quinases TOR/metabolismo , Triazinas/química , Triazinas/farmacocinética , Triazinas/farmacologia , Triazinas/uso terapêuticoRESUMO
mTOR is a critical regulator of cellular signaling downstream of multiple growth factors. The mTOR/PI3K/AKT pathway is frequently mutated in human cancers and is thus an important oncology target. Herein we report the evolution of our program to discover ATP-competitive mTOR inhibitors that demonstrate improved pharmacokinetic properties and selectivity compared to our previous leads. Through targeted SAR and structure-guided design, new imidazopyridine and imidazopyridazine scaffolds were identified that demonstrated superior inhibition of mTOR in cellular assays, selectivity over the closely related PIKK family and improved in vivo clearance over our previously reported benzimidazole series.
Assuntos
Inibidores de Proteínas Quinases/química , Piridazinas/química , Piridinas/química , Serina-Treonina Quinases TOR/antagonistas & inibidores , Animais , Benzimidazóis/química , Sítios de Ligação , Ligação Competitiva , Cristalografia por Raios X , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos , Meia-Vida , Humanos , Imidazóis/química , Masculino , Camundongos , Microssomos Hepáticos/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/farmacocinética , Estrutura Terciária de Proteína , Piridazinas/síntese química , Piridazinas/farmacocinética , Piridinas/síntese química , Piridinas/farmacocinética , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Relação Estrutura-Atividade , Serina-Treonina Quinases TOR/metabolismoRESUMO
A highly selective series of inhibitors of the class I phosphatidylinositol 3-kinases (PI3Ks) has been designed and synthesized. Starting from the dual PI3K/mTOR inhibitor 5, a structure-based approach was used to improve potency and selectivity, resulting in the identification of 54 as a potent inhibitor of the class I PI3Ks with excellent selectivity over mTOR, related phosphatidylinositol kinases, and a broad panel of protein kinases. Compound 54 demonstrated a robust PD-PK relationship inhibiting the PI3K/Akt pathway in vivo in a mouse model, and it potently inhibited tumor growth in a U-87 MG xenograft model with an activated PI3K/Akt pathway.
Assuntos
Classe I de Fosfatidilinositol 3-Quinases/antagonistas & inibidores , Piperazinas/síntese química , Piridinas/síntese química , Sulfonamidas/síntese química , Triazinas/síntese química , Animais , Disponibilidade Biológica , Classe I de Fosfatidilinositol 3-Quinases/fisiologia , Cristalografia por Raios X , Desenho de Fármacos , Feminino , Humanos , Indazóis/síntese química , Indazóis/farmacocinética , Indazóis/farmacologia , Camundongos , Camundongos Nus , Microssomos Hepáticos/metabolismo , Modelos Moleculares , Piperazinas/farmacocinética , Piperazinas/farmacologia , Proteínas Proto-Oncogênicas c-akt/fisiologia , Purinas/síntese química , Purinas/farmacocinética , Purinas/farmacologia , Pirazóis/síntese química , Pirazóis/farmacocinética , Pirazóis/farmacologia , Piridinas/farmacocinética , Piridinas/farmacologia , Pirimidinas/síntese química , Pirimidinas/farmacocinética , Pirimidinas/farmacologia , Ratos , Transdução de Sinais , Relação Estrutura-Atividade , Sulfonamidas/farmacocinética , Sulfonamidas/farmacologia , Sulfonas/síntese química , Sulfonas/farmacocinética , Sulfonas/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Triazinas/farmacocinética , Triazinas/farmacologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
N-(6-(6-Chloro-5-(4-fluorophenylsulfonamido)pyridin-3-yl)benzo[d]thiazol-2-yl)acetamide (1) is a potent and efficacious inhibitor of PI3Kα and mTOR in vitro and in vivo. However, in hepatocyte and in vivo metabolism studies, 1 was found to undergo deacetylation on the 2-amino substituent of the benzothiazole. As an approach to reduce or eliminate this metabolic deacetylation, a variety of 6,5-heterocyclic analogues were examined as an alternative to the benzothiazole ring. Imidazopyridazine 10 was found to have similar in vitro potency and in vivo efficacy relative to 1, while only minimal amounts of the corresponding deacetylated metabolite of 10 were observed in hepatocytes.
Assuntos
Antineoplásicos/síntese química , Inibidores de Fosfoinositídeo-3 Quinase , Piridinas/síntese química , Sulfonamidas/síntese química , Serina-Treonina Quinases TOR/antagonistas & inibidores , Animais , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Cães , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Hepatócitos/metabolismo , Imidazóis/síntese química , Imidazóis/farmacocinética , Imidazóis/farmacologia , Camundongos , Camundongos Nus , Modelos Moleculares , Transplante de Neoplasias , Oxazóis/síntese química , Oxazóis/química , Oxazóis/farmacologia , Piridazinas/síntese química , Piridazinas/farmacocinética , Piridazinas/farmacologia , Piridinas/farmacocinética , Piridinas/farmacologia , Ratos , Relação Estrutura-Atividade , Sulfonamidas/farmacocinética , Sulfonamidas/farmacologia , Tiazóis/síntese química , Tiazóis/química , Tiazóis/farmacologia , Transplante HeterólogoRESUMO
The phosphoinositide 3-kinase (PI3K) family catalyzes the ATP-dependent phosphorylation of the 3'-hydroxyl group of phosphatidylinositols and plays an important role in cell growth and survival. There is abundant evidence demonstrating that PI3K signaling is dysregulated in many human cancers, suggesting that therapeutics targeting the PI3K pathway may have utility for the treatment of cancer. Our efforts to identify potent, efficacious, and orally available PI3K/mammalian target of rapamycin (mTOR) dual inhibitors resulted in the discovery of a series of substituted quinolines and quinoxalines derivatives. In this report, we describe the structure-activity relationships, selectivity, and pharmacokinetic data of this series and illustrate the in vivo pharmacodynamic and efficacy data for a representative compound.
Assuntos
Inibidores de Fosfoinositídeo-3 Quinase , Quinolinas/síntese química , Quinoxalinas/síntese química , Serina-Treonina Quinases TOR/antagonistas & inibidores , Animais , Disponibilidade Biológica , Cristalografia por Raios X , Humanos , Técnicas In Vitro , Fígado/irrigação sanguínea , Fígado/metabolismo , Masculino , Camundongos , Modelos Moleculares , Fosfatidilinositol 3-Quinases/química , Fosforilação , Ligação Proteica , Conformação Proteica , Quinolinas/farmacocinética , Quinolinas/farmacologia , Quinoxalinas/farmacocinética , Quinoxalinas/farmacologia , Ratos , Ratos Sprague-Dawley , Relação Estrutura-Atividade , Serina-Treonina Quinases TOR/química , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
mTOR is part of the PI3K/AKT pathway and is a central regulator of cell growth and survival. Since many cancers display mutations linked to the mTOR signaling pathway, mTOR has emerged as an important target for oncology therapy. Herein, we report the discovery of triazine benzimidazole inhibitors that inhibit mTOR kinase activity with up to 200-fold selectivity over the structurally homologous kinase PI3Kα. When tested in a panel of cancer cell lines displaying various mutations, a selective inhibitor from this series inhibited cellular proliferation with a mean IC(50) of 0.41 µM. Lead compound 42 demonstrated up to 83% inhibition of mTOR substrate phosphorylation in a murine pharmacodynamic model.
Assuntos
Benzimidazóis/farmacologia , Descoberta de Drogas , Serina-Treonina Quinases TOR/antagonistas & inibidores , Triazinas/farmacologia , Benzimidazóis/química , Linhagem Celular Tumoral , Cristalografia por Raios X , Humanos , Ligação de Hidrogênio , Concentração Inibidora 50 , Modelos Moleculares , Relação Estrutura-Atividade , Triazinas/químicaRESUMO
Phosphoinositide 3-kinase α (PI3Kα) is a lipid kinase that plays a key regulatory role in several cellular processes. The mutation or amplification of this kinase in humans has been implicated in the growth of multiple tumor types. Consequently, PI3Kα has become a target of intense research for drug discovery. Our studies began with the identification of benzothiazole compound 1 from a high throughput screen. Extensive SAR studies led to the discovery of sulfonamide 45 as an early lead, based on its in vitro cellular potency. Subsequent modifications of the central pyrimidine ring dramatically improved enzyme and cellular potency and led to the identification of chloropyridine 70. Further arylsulfonamide SAR studies optimized in vitro clearance and led to the identification of 82 as a potent dual inhibitor of PI3K and mTOR. This molecule exhibited potent enzyme and cell activity, low clearance, and high oral bioavailability. In addition, compound 82 demonstrated tumor growth inhibition in U-87 MG, A549, and HCT116 tumor xenograft models.
Assuntos
Antineoplásicos/síntese química , Benzotiazóis/síntese química , Inibidores de Fosfoinositídeo-3 Quinase , Sulfonamidas/síntese química , Serina-Treonina Quinases TOR/antagonistas & inibidores , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Benzotiazóis/química , Benzotiazóis/farmacologia , Sítios de Ligação , Disponibilidade Biológica , Linhagem Celular Tumoral , Cristalografia por Raios X , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Camundongos , Camundongos Nus , Modelos Moleculares , Transplante de Neoplasias , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Relação Estrutura-Atividade , Sulfonamidas/química , Sulfonamidas/farmacologia , Transplante HeterólogoRESUMO
A screening campaign was implemented utilizing capillary electrophoresis as a primary assay to discover binders to the cancer target Akt1 from a crude natural extract library. Fungal extracts with binding activities were characterized for biochemical inhibition of Akt1 to phosphorylate the downstream substrate protein Bad. One of the crude extracts with bioactivity selected for isolation and structure elucidation from fermentation of the fungal culture Oidiodendron sp. F01895 yielded a new trihydroxy phthalide (1). The structure of 1 was determined by a combination of 1D and 2D NMR spectroscopic data along with high-resolution mass spectrometric data. Compound 1 displays inhibition of Akt1 biochemical activity in vitro and confers growth inhibition on some cancer-derived cell lines in culture.