RESUMEN
The profound efficacy of pan-BET inhibitors is well documented, but these epigenetic agents have shown pharmacology-driven toxicity in oncology clinical trials. The opportunity to identify inhibitors with an improved safety profile by selective targeting of a subset of the eight bromodomains of the BET family has triggered extensive medicinal chemistry efforts. In this article, we disclose the identification of potent and selective drug-like pan-BD2 inhibitors such as pyrazole 23 (GSK809) and furan 24 (GSK743) that were derived from the pyrrole fragment 6. We transpose the key learnings from a previous pyridone series (GSK620 2 as a representative example) to this novel class of inhibitors, which are characterized by significantly improved solubility relative to our previous research.
Asunto(s)
Furanos/farmacología , Proteínas/antagonistas & inhibidores , Pirazoles/farmacología , Relación Dosis-Respuesta a Droga , Furanos/química , Humanos , Estructura Molecular , Proteínas/metabolismo , Pirazoles/química , Relación Estructura-ActividadRESUMEN
Second-generation bromodomain and extra terminal (BET) inhibitors, which selectively target one of the two bromodomains in the BET proteins, have begun to emerge in the literature. These inhibitors aim to help determine the roles and functions of each domain and assess whether they can demonstrate an improved safety profile in clinical settings compared to pan-BET inhibitors. Herein, we describe the discovery of a novel BET BD2-selective chemotype using a structure-based drug design from a hit identified by DNA-encoded library technologies, showing a structural differentiation from key previously reported greater than 100-fold BD2-selective chemotypes GSK620, GSK046, and ABBV-744. Following a structure-based hypothesis for the selectivity and optimization of the physicochemical properties of the series, we identified 60 (GSK040), an in vitro ready and in vivo capable BET BD2-inhibitor of unprecedented selectivity (5000-fold) against BET BD1, excellent selectivity against other bromodomains, and good physicochemical properties. This novel chemical probe can be added to the toolbox used in the advancement of epigenetics research.
Asunto(s)
ADN/química , Descubrimiento de Drogas , Proteínas/antagonistas & inhibidores , Bibliotecas de Moléculas Pequeñas/farmacología , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos , Humanos , Estructura Molecular , Dominios Proteicos/efectos de los fármacos , Proteínas/metabolismo , Bibliotecas de Moléculas Pequeñas/síntesis química , Bibliotecas de Moléculas Pequeñas/química , Relación Estructura-ActividadRESUMEN
Domain-specific BET bromodomain ligands represent an attractive target for drug discovery with the potential to unlock the therapeutic benefits of antagonizing these proteins without eliciting the toxicological aspects seen with pan-BET inhibitors. While we have reported several distinct classes of BD2 selective compounds, namely, GSK620, GSK549, and GSK046, only GSK046 shows high aqueous solubility. Herein, we describe the lead optimization of a further class of highly soluble compounds based upon a picolinamide chemotype. Focusing on achieving >1000-fold selectivity for BD2 over BD1 ,while retaining favorable physical chemical properties, compound 36 was identified as being 2000-fold selective for BD2 over BD1 (Brd4 data) with >1 mg/mL solubility in FaSSIF media. 36 represents a valuable new in vivo ready molecule for the exploration of the BD2 phenotype.
Asunto(s)
Proteínas de Ciclo Celular/antagonistas & inhibidores , Piridinas/farmacología , Factores de Transcripción/antagonistas & inhibidores , Proteínas de Ciclo Celular/metabolismo , Relación Dosis-Respuesta a Droga , Humanos , Modelos Moleculares , Estructura Molecular , Piridinas/química , Relación Estructura-Actividad , Factores de Transcripción/metabolismoRESUMEN
A number of reports have recently been published describing the discovery and optimization of bromo and extraterminal inhibitors which are selective for the second bromodomain (BD2); these include our own work toward GSK046 (3) and GSK620 (5). This paper describes our approach to mitigating the genotoxicity risk of GSK046 by replacement of the acetamide functionality with a heterocyclic ring. This was followed by a template-hopping and hybridization approach, guided by structure-based drug design, to incorporate learnings from other BD2-selective series, optimize the vector for the amide region, and explore the ZA cleft, leading to the identification of potent, selective, and bioavailable compounds 28 (GSK452), 39 (GSK737), and 36 (GSK217).
Asunto(s)
Proteínas de Ciclo Celular/antagonistas & inhibidores , Dominios Proteicos/efectos de los fármacos , Bibliotecas de Moléculas Pequeñas/química , Bibliotecas de Moléculas Pequeñas/farmacología , Factores de Transcripción/antagonistas & inhibidores , Proteínas de Ciclo Celular/química , Proteínas de Ciclo Celular/metabolismo , Diseño de Fármacos , Descubrimiento de Drogas , Humanos , Factores de Transcripción/química , Factores de Transcripción/metabolismoRESUMEN
Pan-BET inhibitors have shown profound efficacy in a number of in vivo preclinical models and have entered the clinic in oncology trials where adverse events have been reported. These inhibitors interact equipotently with the eight bromodomains of the BET family of proteins. To better understand the contribution of each domain to their efficacy and to improve from their safety profile, selective inhibitors are required. This Letter discloses the profile of GSK973, a highly selective inhibitor of the second bromodomains of the BET proteins that has undergone extensive preclinical in vitro and in vivo characterization.
RESUMEN
Pan-bromodomain and extra terminal domain (BET) inhibitors interact equipotently with the eight bromodomains of the BET family of proteins and have shown profound efficacy in a number of in vitro phenotypic assays and in vivo pre-clinical models in inflammation or oncology. A number of these inhibitors have progressed to the clinic where pharmacology-driven adverse events have been reported. To better understand the contribution of each domain to their efficacy and improve their safety profile, selective inhibitors are required. This article discloses the profile of GSK046, also known as iBET-BD2, a highly selective inhibitor of the second bromodomains of the BET proteins that has undergone extensive pre-clinical in vitro and in vivo characterization.
Asunto(s)
Amidas/síntesis química , Diseño de Fármacos , Factores de Transcripción/antagonistas & inhibidores , Amidas/química , Amidas/metabolismo , Animales , Derivados del Benceno/química , Sitios de Unión , Proteínas de Ciclo Celular/antagonistas & inhibidores , Proteínas de Ciclo Celular/metabolismo , Cristalografía por Rayos X , Humanos , Microsomas Hepáticos/metabolismo , Simulación de Dinámica Molecular , Dominios Proteicos , Teoría Cuántica , Ratas , Relación Estructura-Actividad , Factores de Transcripción/metabolismoRESUMEN
The profound efficacy, yet associated toxicity of pan-BET inhibitors is well documented. The possibility of an ameliorated safety profile driven by significantly selective (>100-fold) inhibition of a subset of the eight bromodomains is enticing, but challenging given the close homology. Herein, we describe the X-ray crystal structure-directed optimization of a novel weak fragment ligand with a pan-second bromodomain (BD2) bias, to potent and highly BD2 selective inhibitors. A template hopping approach, enabled by our parallel research into an orthogonal template (15, GSK046), was the basis for the high selectivity observed. This culminated in two tool molecules, 20 (GSK620) and 56 (GSK549), which showed an anti-inflammatory phenotype in human whole blood, confirming their cellular target engagement. Excellent broad selectivity, developability, and in vivo oral pharmacokinetics characterize these tools, which we hope will be of broad utility to the field of epigenetics research.
Asunto(s)
Antiinflamatorios/química , Ligandos , Factores de Transcripción/antagonistas & inhibidores , Administración Oral , Amidas/química , Amidas/metabolismo , Amidas/farmacocinética , Animales , Antiinflamatorios/metabolismo , Antiinflamatorios/farmacocinética , Sitios de Unión , Proteínas de Ciclo Celular/antagonistas & inhibidores , Proteínas de Ciclo Celular/metabolismo , Cristalografía por Rayos X , Perros , Semivida , Humanos , Enlace de Hidrógeno , Masculino , Simulación de Dinámica Molecular , Dominios Proteicos , Ratas , Ratas Wistar , Relación Estructura-Actividad , Factores de Transcripción/metabolismoRESUMEN
FTY720 is the first oral small molecule approved for the treatment of people suffering from relapsing-remitting multiple sclerosis. It is a potent agonist of the S1P1 receptor, but its lack of selectivity against the S1P3 receptor has been linked to most of the cardiovascular side effects observed in the clinic. These findings have triggered intensive efforts toward the identification of a second generation of S1P3-sparing S1P1 agonists. We have recently disclosed a series of orally active tetrahydroisoquinoline (THIQ) compounds matching these criteria. In this paper we describe how we defined and implemented a strategy aiming at the discovery of selective structurally distinct follow-up agonists. This effort culminated with the identification of a series of orally active tetrahydropyrazolopyridines.
Asunto(s)
Descubrimiento de Drogas , Pirazoles/administración & dosificación , Pirazoles/farmacología , Piridinas/administración & dosificación , Piridinas/farmacología , Receptores de Lisoesfingolípidos/agonistas , Administración Oral , Animales , Línea Celular , Perros , Relación Dosis-Respuesta a Droga , Humanos , Masculino , Ratones , Ratones Endogámicos , Estructura Molecular , Pirazoles/síntesis química , Pirazoles/química , Piridinas/síntesis química , Piridinas/química , Ratas , Ratas Endogámicas Lew , Ratas Sprague-Dawley , Receptores de Esfingosina-1-Fosfato , Relación Estructura-ActividadRESUMEN
Sphingosine-1-phosphate (S1P(1)) receptor agonists such as Fingolimod (FTY-720) are a novel class of immunomodulators that have clinical utility in the treatment of remitting relapsing multiples sclerosis. This class of compound act by inducing peripheral lymphopenia. Using an integrated pharmacokinetic/pharmacodynamic (PK-PD) approach based on an in vivo rat model, novel S1P(1) agonists were identified with a predicted more rapid rate of reversibility of lymphocyte reduction in human compared to Fingolimod. The in vivo potency of 15 compounds based on PK-PD modelling of the rat lymphocyte reduction model was correlated with in vitro measures of potency at the S1P(1) receptor using ß arrestin recruitment and G-protein signalling. A structurally novel S1P(1) agonist was identified and predictions of human pharmacokinetics and clinical dose are presented.
Asunto(s)
Lisofosfolípidos/agonistas , Glicoles de Propileno/farmacocinética , Esfingosina/análogos & derivados , Animales , Arrestina/metabolismo , Clorhidrato de Fingolimod , Proteínas de Unión al GTP/metabolismo , Linfocitos/efectos de los fármacos , Linfocitos/metabolismo , Lisofosfolípidos/metabolismo , Masculino , Esclerosis Múltiple Recurrente-Remitente/tratamiento farmacológico , Glicoles de Propileno/farmacología , Glicoles de Propileno/uso terapéutico , Ratas , Ratas Endogámicas , Transducción de Señal , Esfingosina/agonistas , Esfingosina/metabolismo , Esfingosina/farmacocinética , Esfingosina/farmacología , Esfingosina/uso terapéuticoRESUMEN
2-Amino-2-(4-octylphenethyl)propane-1,3-diol 1 (fingolimod, FTY720) has been recently marketed in the United States for the treatment of patients with remitting relapsing multiple sclerosis (RRMS). Its efficacy has been primarily linked to the agonism on T cells of S1P(1), one of the five sphingosine 1-phosphate (S1P) G-protein-coupled receptors, while its cardiovascular side effects have been associated with activity at S1P(3). Emerging data suggest that the ability of this molecule to cross the blood-brain barrier and to interact with both S1P(1) and S1P(5) in the central nervous system (CNS) may contribute to its efficacy in treating patients with RRMS. We have recently disclosed the structure of an advanced, first generation S1P(3)-sparing S1P(1) agonist, a zwitterion with limited CNS exposure. In this Article, we highlight our strategy toward the identification of CNS-penetrant S1P(3)-sparing S1P(1) and S1P(5) agonists resulting in the discovery of 5-(3-{2-[2-hydroxy-1-(hydroxymethyl)ethyl]-5-methyl-1,2,3,4-tetrahydro-6-isoquinolinyl}-1,2,4-oxadiazol-5-yl)-2-[(1-methylethyl)oxy]benzonitrile 15. Its exceptional in vivo potency and good pharmacokinetic properties translate into a very low predicted therapeutic dose in human (<1 mg p.o. once daily).
Asunto(s)
Azepinas/síntesis química , Encéfalo/metabolismo , Isoquinolinas/síntesis química , Oxadiazoles/síntesis química , Receptores de Lisoesfingolípidos/agonistas , Administración Oral , Animales , Azepinas/farmacocinética , Azepinas/farmacología , Disponibilidad Biológica , Barrera Hematoencefálica/metabolismo , Línea Celular , Permeabilidad de la Membrana Celular , Perros , Isoquinolinas/farmacocinética , Isoquinolinas/farmacología , Esclerosis Múltiple Recurrente-Remitente/tratamiento farmacológico , Oxadiazoles/farmacocinética , Oxadiazoles/farmacología , Ratas , Receptores de Lisoesfingolípidos/metabolismo , SolubilidadRESUMEN
Gilenya (fingolimod, FTY720) was recently approved by the U.S. FDA for the treatment of patients with remitting relapsing multiple sclerosis (RRMS). It is a potent agonist of four of the five sphingosine 1-phosphate (S1P) G-protein-coupled receptors (S1P1 and S1P3-5). It has been postulated that fingolimod's efficacy is due to S1P1 agonism, while its cardiovascular side effects (transient bradycardia and hypertension) are due to S1P3 agonism. We have discovered a series of selective S1P1 agonists, which includes 3-[6-(5-{3-cyano-4-[(1-methylethyl)oxy]phenyl}-1,2,4-oxadiazol-3-yl)-5-methyl-3,4-dihydro-2(1H)-isoquinolinyl]propanoate, 20, a potent, S1P3-sparing, orally active S1P1 agonist. Compound 20 is as efficacious as fingolimod in a collagen-induced arthritis model and shows excellent pharmacokinetic properties preclinically. Importantly, the selectivity of 20 against S1P3 is responsible for an absence of cardiovascular signal in telemetered rats, even at high dose levels.