RESUMO
Previous efforts from our laboratory demonstrated that (E)-3-((3-(E)-vinylaryl)-1H-indazol-6-yl)methylene)-indolin-2-ones are potent PLK4 inhibitors with in vivo anticancer efficacy upon IP dosing. As part of a continued effort to develop selective and orally efficacious inhibitors, we examined variations on this theme wherein 'directly-linked' aromatics, pendant from the indazole core, replace the arylvinyl moiety. Herein, we describe the design and optimization of this series which was ultimately superseded by (3-aryl-1H-indazol-6-yl)spiro[cyclopropane-1,3'-indolin]-2'-ones. The latter compounds are potent and selective inhibitors of PLK4 with oral exposure in rodents and in vivo anticancer activity. Compound 13b, in particular, has a bioavailability of 22% and achieved a 96% tumor growth inhibition in an MDA-MB-468 xenograft study.
Assuntos
Antineoplásicos/farmacologia , Indóis/química , Indóis/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Administração Oral , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacocinética , Área Sob a Curva , Linhagem Celular Tumoral , Desenho de Fármacos , Xenoenxertos , Humanos , Indóis/administração & dosagem , Indóis/farmacocinética , Camundongos , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/farmacocinética , RatosRESUMO
This work describes a scaffold hopping exercise that begins with known imidazo[1,2-a]pyrazines, briefly explores pyrazolo[1,5-a][1,3,5]triazines, and ultimately yields pyrazolo[1,5-a]pyrimidines as a novel class of potent TTK inhibitors. An X-ray structure of a representative compound is consistent with 1(1)/2 type inhibition and provides structural insight to aid subsequent optimization of in vitro activity and physicochemical and pharmacokinetic properties. Incorporation of polar moieties in the hydrophobic and solvent accessible regions modulates physicochemical properties while maintaining potency. Compounds with enhanced oral exposure were identified for xenograft studies. The work culminates in the identification of a potent (TTK K i = 0.1 nM), highly selective, orally bioavailable anticancer agent (CFI-402257) for IND enabling studies.
RESUMO
TTK/Mps1 is a key kinase controlling progression of cell division via participation in the mitotic spindle assembly checkpoint and is overexpressed in a number of human cancers. Herein we report the discovery of 4-(4-aminopyrazolo[1,5-a][1,3,5]triazin-8-yl)benzamides as a potent, novel class of TTK inhibitors. The series was identified by means of bioisosteric replacement of the related imidazopyrazine and imidazopyridazine scaffolds. Optimization led to the identification of compounds with excellent potency (Ki=0.8nM) and exceptional kinase selectivity. The SAR indicates a strong dependence of activity on the presence of the N-cyclopropyl-2-methylbenzamide moiety delineating the geometry for 1½ type kinase inhibitor. Molecular modeling indicates the extensive and optimal contacts, mediated through H-bonds and hydrophobic interactions, are responsible for the selectivity and potency of the inhibitors. The compounds demonstrate a strong anti-proliferative activity in a panel of human cancer cell lines (HCT116 GI50<15nM) and good rodent pharmacokinetics (oral %F 97%).
Assuntos
Antineoplásicos/farmacologia , Benzamidas/farmacologia , Proteínas de Ciclo Celular/antagonistas & inibidores , Descoberta de Drogas , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/antagonistas & inibidores , Triazinas/farmacologia , Administração Oral , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Benzamidas/administração & dosagem , Benzamidas/química , Disponibilidade Biológica , Proteínas de Ciclo Celular/metabolismo , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Camundongos , Modelos Moleculares , Estrutura Molecular , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/química , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Tirosina Quinases/metabolismo , Ratos , Relação Estrutura-Atividade , Triazinas/administração & dosagem , Triazinas/químicaRESUMO
The acetamido and carboxamido substituted 3-(1H-indazol-3-yl)benzenesulfonamides are potent TTK inhibitors. However, they display modest ability to attenuate cancer cell growth; their physicochemical properties, and attendant pharmacokinetic parameters, are not drug-like. By eliminating the polar 3-sulfonamide group and grafting a heterocycle at the 4 position of the phenyl ring, potent inhibitors with oral exposure were obtained. An X-ray cocrystal structure and a refined binding model allowed for a structure guided approach. Systematic optimization resulted in novel TTK inhibitors, namely 3-(4-(heterocyclyl)phenyl)-1H-indazole-5-carboxamides. Compounds incorporating the 3-hydroxy-8-azabicyclo[3.2.1]octan-8-yl bicyclic system were potent (TTK IC50 < 10 nM, HCT116 GI50 < 0.1 µM), displayed low off-target activity (>500×), and microsomal stability (T(1/2) > 30 min). A subset was tested in rodent PK and mouse xenograft models of human cancer. Compound 75 (CFI-401870) recapitulated the phenotype of TTK RNAi, demonstrated in vivo tumor growth inhibition upon oral dosing, and was selected for preclinical evaluation.
Assuntos
Proteínas de Ciclo Celular/antagonistas & inibidores , Neoplasias do Colo/tratamento farmacológico , Indazóis/química , Indazóis/uso terapêutico , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/antagonistas & inibidores , Administração Oral , Animais , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Colo/efeitos dos fármacos , Colo/enzimologia , Colo/patologia , Neoplasias do Colo/enzimologia , Neoplasias do Colo/patologia , Cristalografia por Raios X , Feminino , Humanos , Indazóis/administração & dosagem , Indazóis/farmacologia , Camundongos Nus , Modelos Moleculares , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Tirosina Quinases/metabolismoRESUMO
Previous publications from our laboratory have introduced novel inhibitors of Polo-like kinase 4 (PLK4), a mitotic kinase identified as a potential target for cancer therapy. The search for potent and selective PLK4 inhibitors yielded (E)-3-((1Hindazol-6-yl)methylene)indolin-2-ones, which were superseded by the bioisosteric 2-(1H-indazol-6-yl)spiro[cyclopropane-1,3'-indolin]-2'-ones, e.g., 3. The later scaffold confers improved drug-like properties and incorporates two stereogenic centers. This work reports the discovery of a novel one-pot double SN2 displacement reaction for the stereoselective installation of the desired asymmetric centers and confirms the stereochemistry of the most potent stereoisomer, e.g., 44. Subsequent work keys on the optimization of the oral exposure of nanomolar PLK4 inhibitors with potent cancer cell growth inhibitory activity. A short list of compounds with superior potency and pharmacokinetic properties in rodents and dogs was studied in mouse models of tumor growth. We conclude with the identification of compound 48 (designated CFI-400945) as a novel clinical candidate for cancer therapy.
Assuntos
Antineoplásicos/farmacologia , Indazóis/farmacologia , Indóis/farmacologia , Neoplasias/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/análise , Administração Oral , Animais , Antineoplásicos/química , Antineoplásicos/farmacocinética , Disponibilidade Biológica , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cães , Relação Dose-Resposta a Droga , Descoberta de Drogas , Feminino , Células HCT116 , Humanos , Indazóis/química , Indazóis/farmacocinética , Indóis/química , Indóis/farmacocinética , Células MCF-7 , Masculino , Camundongos Nus , Camundongos SCID , Modelos Químicos , Estrutura Molecular , Neoplasias/metabolismo , Neoplasias/patologia , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacocinética , Proteínas Serina-Treonina Quinases/química , Proteínas Serina-Treonina Quinases/metabolismo , Ratos , Relação Estrutura-Atividade , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Polo-like kinase 4 (PLK4), a unique member of the polo-like kinase family of serine-threonine kinases, is a master regulator of centriole duplication that is important for maintaining genome integrity. Overexpression of PLK4 is found in several human cancers and is linked with a predisposition to tumorigenesis. Previous efforts to identify potent and efficacious PLK4 inhibitors resulted in the discovery of (E)-3-((1H-indazol-6-yl)methylene)indolin-2-ones, which are superseded by the bioisosteric 2-(1H-indazol-6-yl)spiro[cyclopropane-1,3'-indolin]-2'-ones reported herein. Optimization of this new cyclopropane-linked series was based on a computational model of a PLK4 X-ray structure and SAR attained from the analogous alkenelinked series. The racemic cyclopropane-linked compounds showed PLK4 affinity and antiproliferative activity comparable to their alkene-linked congeners with improved hysicochemical, ADME, and pharmacokinetic properties. Positive xenograft results from the MDA-MB-468 human breast cancer xenograft model for compound 18 support the investigation of PLK4 inhibitors as anticancer therapeutics. A PLK4 X-ray co-structure with racemate 18 revealed preferential binding of the 1R,2S enantiomer to the PLK4 kinase domain.
Assuntos
Antineoplásicos/farmacologia , Indóis/farmacologia , Neoplasias/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Compostos de Espiro/farmacologia , Administração Oral , Animais , Antineoplásicos/química , Antineoplásicos/farmacocinética , Disponibilidade Biológica , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Desenho de Fármacos , Descoberta de Drogas , Ensaios de Seleção de Medicamentos Antitumorais , Células HCT116 , Humanos , Indóis/química , Indóis/farmacocinética , Células MCF-7 , Camundongos , Modelos Químicos , Estrutura Molecular , Neoplasias/metabolismo , Neoplasias/patologia , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacocinética , Proteínas Serina-Treonina Quinases/química , Proteínas Serina-Treonina Quinases/metabolismo , Ratos , Compostos de Espiro/química , Compostos de Espiro/farmacocinética , Relação Estrutura-Atividade , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
TTK kinase was identified by in-house siRNA screen and pursued as a tractable, novel target for cancer treatment. A screening campaign and systematic optimization, supported by computer modeling led to an indazole core with key sulfamoylphenyl and acetamido moieties at positions 3 and 5, respectively, establishing a novel chemical class culminating in identification of 72 (CFI-400936). This potent inhibitor of TTK (IC50=3.6nM) demonstrated good activity in cell based assay and selectivity against a panel of human kinases. A co-complex TTK X-ray crystal structure and results of a xenograft study with TTK inhibitors from this class are described.
Assuntos
Amidas/farmacologia , Benzenoacetamidas/farmacologia , Proteínas de Ciclo Celular/antagonistas & inibidores , Descoberta de Drogas , Indazóis/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/antagonistas & inibidores , Amidas/síntese química , Amidas/química , Benzenoacetamidas/síntese química , Benzenoacetamidas/química , Proteínas de Ciclo Celular/metabolismo , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Humanos , Indazóis/síntese química , Indazóis/química , Modelos Moleculares , Estrutura Molecular , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Tirosina Quinases/metabolismo , Relação Estrutura-AtividadeRESUMO
The family of Polo-like kinases is important in the regulation of mitotic progression; this work keys on one member, namely Polo-like kinase 4 (PLK4). PLK4 has been identified as a candidate anticancer target which prompted a search for potent and selective inhibitors of PLK4. The body of the paper describes lead generation and optimization work which yielded nanomolar PLK4 inhibitors. Lead generation began with directed virtual screening, using a ligand-based focused library and a PLK4 homology model. Validated hits were used as starting points for the design and discovery of PLK4 inhibitors of novel structure, namely (E)-3-((1H-indazol-6-yl)methylene)indolin-2-ones. Computational models, based on a published X-ray structure (PLK4 kinase domain), were used to understand and optimize the in vitro activity of the series; potent antiproliferative activity was obtained. The kinase selectivity profile and cell cycle analysis of selected inhibitors are described. The results of a xenograft study with an optimized compound 50 (designated CFI-400437) support the potential of these novel PLK4 inhibitors for cancer therapy.
Assuntos
Antineoplásicos/síntese química , Indazóis/síntese química , Indóis/síntese química , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Indazóis/química , Indazóis/farmacologia , Indóis/química , Indóis/farmacologia , Camundongos , Camundongos SCID , Modelos Moleculares , Estereoisomerismo , Relação Estrutura-Atividade , Transplante HeterólogoRESUMO
This report describes the investigation of a series of 5,7-disubstituted imidazo[5,1-f][1,2,4]triazine inhibitors of insulin-like growth factor-1 receptor (IGF-1R) and insulin receptor (IR). Structure-activity relationship exploration and optimization leading to the identification, characterization, and pharmacological activity of compound 9b, a potent, selective, well-tolerated, and orally bioavailable dual inhibitor of IGF-1R and IR with in vivo efficacy in tumor xenograft models, is discussed.
RESUMO
A general and efficient synthesis of 5-aryl imidazo[1,5- a]pyrazines by palladium-catalyzed coupling of the corresponding 8-substituted derivatives with aryl halides is described. The scope of this new reaction for the imidazo[1,5- a]pyrazine ring system was explored using three readily available 8-substituted precursors, X = NH2, NMe2, and OMe, as well as 8-aryl derivatives, X = Ar'. On the basis of these results as well as studies using a deuterated derivative, a Heck-like mechanism is proposed for this transformation.
Assuntos
Hidrocarbonetos Bromados/química , Imidazóis/síntese química , Paládio/química , Pirazinas/síntese química , Catálise , Técnicas de Química Combinatória , Imidazóis/química , Estrutura Molecular , Pirazinas/química , EstereoisomerismoRESUMO
An efficient three-step construction of the highly oxygenated D-ring of the kinamycin antibiotics is reported for a simple model system. A comparison of the spectroscopic characteristics of the synthetic models with those of natural kinamycin F, which is suspected to be the bioactive form of the kinamycins, leads to the conclusion that the favored D-ring conformation of kinamycin F differs from that of the other partially or fully acylated variants.
Assuntos
Antibacterianos/química , Antibacterianos/síntese química , Modelos Moleculares , Conformação Molecular , Estrutura Molecular , Quinonas/síntese química , Quinonas/química , Streptomyces/químicaRESUMO
The cell growth and cell cycle inhibitory properties of the bacterial metabolites kinamycin A and kinamycin C were investigated in an attempt to determine their mechanism of action and to develop these or their analogs as anticancer agents. Both kinamycin A and kinamycin C have a highly unusual and potentially reactive diazo group. Even with short incubations, both the kinamycins were shown to have very potent cell growth inhibitory effects on either Chinese hamster ovary or K562 cells. Kinamycin C induced a rapid apoptotic response in K562 cells. The cell cycle analysis results in synchronized Chinese hamster ovary cells treated with kinamycin A revealed that they only displayed a G1/S phase block upon entry to the second cycle. Both kinamycins inhibited the catalytic decatenation activity of DNA topoisomerase IIalpha, but neither kinamycin acted as a topoisomerase II poison. Their inhibition of catalytic activity was not correlated with cell growth inhibitory effects. Pretreatment of the kinamycins with dithiothreitol protected the topoisomerase IIalpha activity, which suggested that they may be targeting critical protein sulfhydryl groups, either through reaction with the quinone or with an activated electrophilic diazo group. Neither kinamycin A nor kinamycin C intercalated into DNA, nor were they able to cross-link DNA. Although the cellular target(s) of the kinamycins has yet to be identified, the cluster map analysis, and the cell cycle and proapoptotic effects suggest that kinamycin C has a target different than other established anticancer compounds.
Assuntos
Antibióticos Antineoplásicos/farmacologia , Compostos Azo/farmacologia , Ciclo Celular/efeitos dos fármacos , Naftoquinonas/farmacologia , Adenosina Trifosfatases/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Antibióticos Antineoplásicos/química , Antígenos de Neoplasias/metabolismo , Compostos Azo/química , Células CHO , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Análise por Conglomerados , Cricetinae , Reagentes de Ligações Cruzadas , DNA Girase/metabolismo , DNA Topoisomerases Tipo II/metabolismo , DNA de Neoplasias/genética , DNA Super-Helicoidal/metabolismo , Proteínas de Ligação a DNA/metabolismo , Escherichia coli/enzimologia , Humanos , Células K562 , NAD/metabolismo , Naftoquinonas/química , Plasmídeos/genética , Quinonas/química , Quinonas/farmacologia , Inibidores da Topoisomerase IIRESUMO
Theoretical and chemical studies of the reactivity of isoprekinamycin, the kinamycins, and the lomaiviticins support the proposal that these natural products exhibit enhanced diazonium salt character and may owe their antitumor antibiotic properties to their ability to act as electrophilic azo-coupling agents in vivo.