RESUMEN
Protein arginine methyltransferase 5 (PRMT5) overexpression in hematologic and solid tumors methylates arginine residues on cellular proteins involved in important cancer functions including cell-cycle regulation, mRNA splicing, cell differentiation, cell signaling, and apoptosis. PRMT5 methyltransferase function has been linked with high rates of tumor cell proliferation and decreased overall survival, and PRMT5 inhibitors are currently being explored as an approach for targeting cancer-specific dependencies due to PRMT5 catalytic function. Here, we describe the discovery of potent and selective S-adenosylmethionine (SAM) competitive PRMT5 inhibitors, with in vitro and in vivo characterization of clinical candidate PF-06939999. Acquired resistance mechanisms were explored through the development of drug resistant cell lines. Our data highlight compound-specific resistance mutations in the PRMT5 enzyme that demonstrate structural constraints in the cofactor binding site that prevent emergence of complete resistance to SAM site inhibitors. PRMT5 inhibition by PF-06939999 treatment reduced proliferation of non-small cell lung cancer (NSCLC) cells, with dose-dependent decreases in symmetric dimethyl arginine (SDMA) levels and changes in alternative splicing of numerous pre-mRNAs. Drug sensitivity to PF-06939999 in NSCLC cells associates with cancer pathways including MYC, cell cycle and spliceosome, and with mutations in splicing factors such as RBM10. Translation of efficacy in mouse tumor xenograft models with splicing mutations provides rationale for therapeutic use of PF-06939999 in the treatment of splicing dysregulated NSCLC.
Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/genética , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Proteína-Arginina N-Metiltransferasas/antagonistas & inhibidores , S-Adenosilmetionina/metabolismo , Animales , Apoptosis , Carcinoma de Pulmón de Células no Pequeñas/patología , Línea Celular Tumoral , Proliferación Celular , Resistencia a Medicamentos , Femenino , Humanos , Neoplasias Pulmonares/patología , RatonesRESUMEN
The structure based drug design, synthesis and structure-activity relationship of a series of C6 sulfur linked triazolopyridine based p38 inhibitors are described. The metabolic deficiencies of this series were overcome through changes in the C6 linker from sulfur to methylene, which was predicted by molecular modeling to be bioisosteric. X-ray of the ethylene linked compound 61 confirmed the predicted binding orientation of the scaffold in the p38 enzyme.
Asunto(s)
Benzamidas/química , Compuestos Bicíclicos Heterocíclicos con Puentes/química , Inhibidores de Proteínas Quinasas/química , Pirimidinas/química , Triazoles/química , Proteínas Quinasas p38 Activadas por Mitógenos/antagonistas & inhibidores , Animales , Benzamidas/síntesis química , Benzamidas/farmacología , Sitios de Unión , Compuestos Bicíclicos Heterocíclicos con Puentes/síntesis química , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Cristalografía por Rayos X , Diseño de Fármacos , Humanos , Microsomas Hepáticos/metabolismo , Modelos Químicos , Modelos Moleculares , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/farmacología , Pirimidinas/síntesis química , Pirimidinas/farmacología , Ratas , Relación Estructura-Actividad , Triazoles/síntesis química , Triazoles/farmacología , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismoRESUMEN
The copper-catalyzed hydroboration of benzylidenecyclopropanes, conveniently accessed in one step from readily available benzaldehydes, is reported. Under otherwise identical reaction conditions, two distinct phosphine ligands grant access to different products by either suppressing or promoting cyclopropane opening via ß-carbon elimination. Computational studies provide insight into how the rigidity and steric environment of these different bis-phosphine ligands influence the relative activation energies of ß-carbon elimination versus protodecupration from the key benzylcopper intermediate. The method tolerates a wide variety of heterocycles prevalent in clinical and pre-clinical drug development, giving access to valuable synthetic intermediates. The versatility of the tertiary cyclopropylboronic ester products is demonstrated through several derivatization reactions.
RESUMEN
Hormones of the neurotrophin family, nerve growth factor (NGF), brain derived neurotrophic factor (BDNF), neurotrophin 3 (NT3), and neurotrophin 4 (NT4), are known to activate the family of Tropomyosin receptor kinases (TrkA, TrkB, and TrkC). Moreover, inhibition of the TrkA kinase pathway in pain has been clinically validated by the NGF antibody tanezumab, leading to significant interest in the development of small molecule inhibitors of TrkA. Furthermore, Trk inhibitors having an acceptable safety profile will require minimal brain availability. Herein, we discuss the discovery of two potent, selective, peripherally restricted, efficacious, and well-tolerated series of pan-Trk inhibitors which successfully delivered three candidate quality compounds 10b, 13b, and 19. All three compounds are predicted to possess low metabolic clearance in human that does not proceed via aldehyde oxidase-catalyzed reactions, thus addressing the potential clearance prediction liability associated with our current pan-Trk development candidate PF-06273340.
Asunto(s)
Descubrimiento de Drogas , Dolor/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Tirosina Quinasas Receptoras/antagonistas & inhibidores , Animales , Humanos , Ligandos , Simulación del Acoplamiento Molecular , Conformación Proteica , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacocinética , Inhibidores de Proteínas Quinasas/uso terapéutico , Piridinas/química , Piridinas/farmacocinética , Piridinas/farmacología , Piridinas/uso terapéutico , Ratas , Proteínas Tirosina Quinasas Receptoras/química , Proteínas Tirosina Quinasas Receptoras/metabolismo , Solubilidad , Relación Estructura-Actividad , Distribución TisularRESUMEN
A new enhancer of zeste homolog 2 (EZH2) inhibitor series comprising a substituted phenyl ring joined to a dimethylpyridone moiety via an amide linkage has been designed. A preferential amide torsion that improved the binding properties of the compounds was identified for this series via computational analysis. Cyclization of the amide linker resulted in a six-membered lactam analogue, compound 18. This transformation significantly improved the ligand efficiency/potency of the cyclized compound relative to its acyclic analogue. Additional optimization of the lactam-containing EZH2 inhibitors focused on lipophilic efficiency (LipE) improvement, which provided compound 31. Compound 31 displayed improved LipE and on-target potency in both biochemical and cellular readouts relative to compound 18. Inhibitor 31 also displayed robust in vivo antitumor growth activity and dose-dependent de-repression of EZH2 target genes.
Asunto(s)
Antineoplásicos/química , Antineoplásicos/farmacología , Diseño de Fármacos , Proteína Potenciadora del Homólogo Zeste 2/antagonistas & inhibidores , Piridonas/química , Piridonas/farmacología , Animales , Antineoplásicos/uso terapéutico , Línea Celular Tumoral , Ciclización , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Femenino , Humanos , Isoquinolinas/química , Isoquinolinas/farmacología , Isoquinolinas/uso terapéutico , Lactamas/química , Lactamas/farmacología , Ratones , Ratones SCID , Modelos Moleculares , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Piridonas/uso terapéuticoRESUMEN
Differences in regioselectivity were observed during the S(N)Ar reaction of amines with unsymmetrical 3,5-dichloropyrazines. This study revealed that when the 2-position of the pyrazine was occupied with an electron-withdrawing group (EWG), nucleophilic attack occurred preferentially at the 5-position. When the 2-position was substituted with an electron-donating group (EDG), nucleophilic attack occurred preferentially at the 3-position. These results are reported along with a computational rationale for the experimental observations based on the Fukui index at the reacting centers.
Asunto(s)
Aminas/química , Hidrocarburos Clorados/química , Pirazinas/química , Electrones , Oxidación-Reducción , EstereoisomerismoRESUMEN
A novel class of heat shock protein 90 (Hsp90) inhibitors was discovered by high-throughput screening and was subsequently optimized using a combination of structure-based design, parallel synthesis, and the application of medicinal chemistry principles. Through this process, the biochemical and cell-based potency of the original HTS lead were substantially improved along with the corresponding metabolic stability properties. These efforts culminated with the identification of a development candidate (compound 42) which displayed desired PK/PD relationships, significant efficacy in a melanoma A2058 xenograft tumor model, and attractive DMPK profiles.
Asunto(s)
Antineoplásicos/síntesis química , Proteínas HSP90 de Choque Térmico/antagonistas & inhibidores , Pirazoles/síntesis química , Pirimidinas/síntesis química , Administración Oral , Animales , Antineoplásicos/farmacocinética , Antineoplásicos/farmacología , Unión Competitiva , Disponibilidad Biológica , Proteínas Sanguíneas/metabolismo , Línea Celular Tumoral , Permeabilidad de la Membrana Celular , Ensayos de Selección de Medicamentos Antitumorales , Estabilidad de Medicamentos , Femenino , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Técnicas In Vitro , Masculino , Melanoma/tratamiento farmacológico , Melanoma/patología , Ratones , Ratones Desnudos , Microsomas Hepáticos/metabolismo , Modelos Moleculares , Trasplante de Neoplasias , Unión Proteica , Pirazoles/farmacocinética , Pirazoles/farmacología , Pirimidinas/farmacocinética , Pirimidinas/farmacología , Ratas , Relación Estructura-Actividad , Trasplante HeterólogoRESUMEN
The synthesis, structure-activity relationship, in vivo activity, and metabolic profile for a series of triazolopyridine-oxazole based p38 inhibitors are described. The deficiencies of the lead structure in the series, CP-808844, were overcome by changes to the C4 aryl group and the triazole side-chain culminating in the identification of several potential clinical candidates.