RESUMEN
Two scaffolds based on 5,6-fused heterocyclic backbones were designed and synthesized as Raf kinase inhibitors. The scaffolds were assessed for in vitro pan-Raf inhibition, activity in cell proliferation and target modulation assays, and pharmacokinetic parameters.
Asunto(s)
Amidas/síntesis química , Diseño de Fármacos , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , Compuestos Heterocíclicos/síntesis química , Quinasas raf/antagonistas & inhibidores , Amidas/química , Amidas/farmacología , Sitios de Unión , Proliferación Celular , Activación Enzimática/efectos de los fármacos , Inhibidores Enzimáticos/química , Compuestos Heterocíclicos/química , Compuestos Heterocíclicos/farmacología , Modelos Moleculares , Estructura Molecular , Relación Estructura-ActividadRESUMEN
Direct pharmacological inhibition of RAS has remained elusive, and efforts to target CRAF have been challenging due to the complex nature of RAF signaling, downstream of activated RAS, and the poor overall kinase selectivity of putative RAF inhibitors. Herein, we describe 15 (LXH254, Aversa, R.; et al. Int. Patent WO2014151616A1, 2014), a selective B/C RAF inhibitor, which was developed by focusing on drug-like properties and selectivity. Our previous tool compound, 3 (RAF709; Nishiguchi, G. A.; et al. J. Med. Chem. 2017, 60, 4969), was potent, selective, efficacious, and well tolerated in preclinical models, but the high human intrinsic clearance precluded further development and prompted further investigation of close analogues. A structure-based approach led to a pyridine series with an alcohol side chain that could interact with the DFG loop and significantly improved cell potency. Further mitigation of human intrinsic clearance and time-dependent inhibition led to the discovery of 15. Due to its excellent properties, it was progressed through toxicology studies and is being tested in phase 1 clinical trials.
Asunto(s)
Antineoplásicos/química , Descubrimiento de Drogas/métodos , Mutación/genética , Inhibidores de Proteínas Quinasas/química , Proteínas Proto-Oncogénicas B-raf/antagonistas & inhibidores , Proteínas Proto-Oncogénicas B-raf/genética , Animales , Antineoplásicos/farmacología , Diseño de Fármacos , Descubrimiento de Drogas/tendencias , Humanos , Simulación del Acoplamiento Molecular/métodos , Simulación del Acoplamiento Molecular/tendencias , Mutación/efectos de los fármacos , Inhibidores de Proteínas Quinasas/farmacología , Ensayos Antitumor por Modelo de Xenoinjerto/métodosRESUMEN
Resistance to the RAF inhibitor vemurafenib arises commonly in melanomas driven by the activated BRAF oncogene. Here, we report antitumor properties of RAF709, a novel ATP-competitive kinase inhibitor with high potency and selectivity against RAF kinases. RAF709 exhibited a mode of RAF inhibition distinct from RAF monomer inhibitors such as vemurafenib, showing equal activity against both RAF monomers and dimers. As a result, RAF709 inhibited MAPK signaling activity in tumor models harboring either BRAFV600 alterations or mutant N- and KRAS-driven signaling, with minimal paradoxical activation of wild-type RAF. In cell lines and murine xenograft models, RAF709 demonstrated selective antitumor activity in tumor cells harboring BRAF or RAS mutations compared with cells with wild-type BRAF and RAS genes. RAF709 demonstrated a direct pharmacokinetic/pharmacodynamic relationship in in vivo tumor models harboring KRAS mutation. Furthermore, RAF709 elicited regression of primary human tumor-derived xenograft models with BRAF, NRAS, or KRAS mutations with excellent tolerability. Our results support further development of inhibitors like RAF709, which represents a next-generation RAF inhibitor with unique biochemical and cellular properties that enables antitumor activities in RAS-mutant tumors.Significance: In an effort to develop RAF inhibitors with the appropriate pharmacological properties to treat RAS mutant tumors, RAF709, a compound with potency, selectivity, and in vivo properties, was developed that will allow preclinical therapeutic hypothesis testing, but also provide an excellent probe to further unravel the complexities of RAF kinase signaling. Cancer Res; 78(6); 1537-48. ©2018 AACR.
Asunto(s)
2,2'-Dipiridil/análogos & derivados , Antineoplásicos/farmacología , Benzamidas/farmacología , Proteínas Proto-Oncogénicas B-raf/genética , Quinasas raf/antagonistas & inhibidores , Proteínas ras/genética , 2,2'-Dipiridil/farmacología , Animales , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Resistencia a Antineoplásicos/efectos de los fármacos , Femenino , Humanos , Quinasas Quinasa Quinasa PAM/antagonistas & inhibidores , Ratones Desnudos , Mutación , Inhibidores de Proteínas Quinasas/farmacología , Multimerización de Proteína , Ensayos Antitumor por Modelo de Xenoinjerto , Quinasas raf/metabolismoRESUMEN
RAS oncogenes have been implicated in >30% of human cancers, all representing high unmet medical need. The exquisite dependency on CRAF kinase in KRAS mutant tumors has been established in genetically engineered mouse models and human tumor cells. To date, many small molecule approaches are under investigation to target CRAF, yet kinase-selective and cellular potent inhibitors remain challenging to identify. Herein, we describe 14 (RAF709) [ Aversa , Biaryl amide compounds as kinase inhibitors and their preparation . WO 2014151616, 2014 ], a selective B/C RAF inhibitor, which was developed through a hypothesis-driven approach focusing on drug-like properties. A key challenge encountered in the medicinal chemistry campaign was maintaining a balance between good solubility and potent cellular activity (suppression of pMEK and proliferation) in KRAS mutant tumor cell lines. We investigated the small molecule crystal structure of lead molecule 7 and hypothesized that disruption of the crystal packing would improve solubility, which led to a change from N-methylpyridone to a tetrahydropyranyl oxy-pyridine derivative. 14 proved to be soluble, kinase selective, and efficacious in a KRAS mutant xenograft model.
Asunto(s)
2,2'-Dipiridil/análogos & derivados , Antineoplásicos/farmacología , Benzamidas/farmacología , Quinasas raf/antagonistas & inhibidores , Proteínas ras/genética , 2,2'-Dipiridil/química , 2,2'-Dipiridil/farmacología , Animales , Antineoplásicos/química , Antineoplásicos/farmacocinética , Benzamidas/química , Cristalografía por Rayos X , Perros , Diseño de Fármacos , Descubrimiento de Drogas , Estabilidad de Medicamentos , Humanos , Concentración 50 Inhibidora , Ratones , Terapia Molecular Dirigida , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Proteínas Proto-Oncogénicas B-raf/química , Proteínas Proto-Oncogénicas p21(ras)/genética , Ratas , Relación Estructura-Actividad , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
The discovery of a highly potent and selective small molecule inhibitor 9 for in vitro target validation of MNK1/2 kinases is described. The aminopyrazine benzimidazole series was derived from an HTS hit and optimized by utilization of a docking model, conformation analysis, and binding pocket comparison against antitargets.
Asunto(s)
Péptidos y Proteínas de Señalización Intracelular/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Sitios de Unión , Células CACO-2/efectos de los fármacos , Diseño de Fármacos , Ensayos Analíticos de Alto Rendimiento/métodos , Humanos , Péptidos y Proteínas de Señalización Intracelular/química , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Simulación del Acoplamiento Molecular , Permeabilidad , Proteínas Serina-Treonina Quinasas/química , Proteínas Serina-Treonina Quinasas/metabolismo , Solubilidad , Relación Estructura-ActividadRESUMEN
The discovery of inhibitors targeting novel allosteric kinase sites is very challenging. Such compounds, however, once identified could offer exquisite levels of selectivity across the kinome. Herein we report our structure-based optimization strategy of a dibenzodiazepine hit 1, discovered in a fragment-based screen, yielding highly potent and selective inhibitors of PAK1 such as 2 and 3. Compound 2 was cocrystallized with PAK1 to confirm binding to an allosteric site and to reveal novel key interactions. Compound 3 modulated PAK1 at the cellular level and due to its selectivity enabled valuable research to interrogate biological functions of the PAK1 kinase.
RESUMEN
Abrogation of errant signaling along the MAPK pathway through the inhibition of B-RAF kinase is a validated approach for the treatment of pathway-dependent cancers. We report the development of imidazo-benzimidazoles as potent B-RAF inhibitors. Robust in vivo efficacy coupled with correlating pharmacokinetic/pharmacodynamic (PKPD) and PD-efficacy relationships led to the identification of RAF265, 1, which has advanced into clinical trials.
RESUMEN
Benzimidazole reverse amides were designed and synthesized as Pan RAF kinase inhibitors. Investigation of the structure-activity relationship of the compounds revealed that they were potent in vitro and exhibited desirable in vivo properties.
RESUMEN
[This corrects the article DOI: 10.1021/ml5002272.].
RESUMEN
A series of arylaminobenzimidazoles was designed and synthesized as Raf kinase inhibitors. Exploration of the structure-activity relationship resulted in compounds that are potent in vitro and show desirable in vivo properties.