RESUMEN
HCV NS5A inhibitors have shown impressive in vitro potency profiles in HCV replicon assays thus making them attractive components for inclusion in an all oral fixed dose combination regimen. Herein, we describe the discovery and characterization of silyl proline-containing HCV NS5A inhibitor MK-8325 with good pan-genotype activity and acceptable pharmacokinetic properties.
Asunto(s)
Antivirales/química , Compuestos Heterocíclicos de 4 o más Anillos/química , Prolina/química , Proteínas no Estructurales Virales/antagonistas & inhibidores , Animales , Antivirales/farmacocinética , Antivirales/farmacología , Sistema Enzimático del Citocromo P-450/metabolismo , Perros , Genotipo , Semivida , Haplorrinos , Hepacivirus/efectos de los fármacos , Hepacivirus/genética , Hepacivirus/fisiología , Compuestos Heterocíclicos de 4 o más Anillos/farmacocinética , Compuestos Heterocíclicos de 4 o más Anillos/farmacología , Humanos , Ratas , Proteínas no Estructurales Virales/metabolismo , Replicación Viral/efectos de los fármacosRESUMEN
Herein, we describe our research efforts to develop unique cores in molecules which function as HCV nonstructural protein 5A (NS5A) inhibitors. In particular, various fused tetracyclic cores were identified which showed genotype and mutant activities comparable to the indole-based tetracyclic core.
Asunto(s)
Indoles/farmacología , Proteínas no Estructurales Virales/antagonistas & inhibidores , Antivirales/farmacología , Hepacivirus/efectos de los fármacosRESUMEN
We describe the impact of proline modifications, in our tetracyclic-indole based series of nonstructural protein 5A (NS5A) inhibitors, to their replicon profiles. This work identified NS5A inhibitors with an improved and flattened resistance profiles.
Asunto(s)
Antivirales/farmacología , Benzofuranos/farmacología , Imidazoles/farmacología , Indoles/química , Prolina/química , Proteínas no Estructurales Virales/antagonistas & inhibidores , Antivirales/química , Benzofuranos/química , Imidazoles/química , Relación Estructura-ActividadRESUMEN
As part of an ongoing effort in NS5A inhibition at Merck we now describe our efforts for introducing substitution around the tetracyclic indole core of MK-8742. Fluoro substitution on the core combined with the fluoro substitutions on the proline ring improved the potency against GT1a Y93H significantly. However, no improvement on GT2b potency was achieved. Limiting the fluoro substitution to C-1 of the tetracyclic indole core had a positive impact on the potency against the resistance associated variants, such as GT1a Y93H and GT2b, and the PK profile as well. Compounds, such as 62, with reduced potency shifts between wild type GT1a to GT2b, GT1a Y93H, and GT1a L31V were identified.
Asunto(s)
Antivirales/farmacología , Benzofuranos/farmacología , Imidazoles/farmacología , Indoles/farmacología , Proteínas no Estructurales Virales/antagonistas & inhibidores , Antivirales/química , Antivirales/farmacocinética , Benzofuranos/química , Benzofuranos/farmacocinética , Imidazoles/química , Imidazoles/farmacocinética , Indoles/química , Indoles/farmacocinética , Relación Estructura-ActividadRESUMEN
A matched and mixed capping SAR study was conducted on the tetracyclic indole class of HCV NS5A inhibitors to examine the influence of modifications of this region on the overall HCV virologic resistance profiles.
Asunto(s)
Antivirales/química , Hepacivirus/metabolismo , Indoles/química , Proteínas no Estructurales Virales/antagonistas & inhibidores , Animales , Antivirales/metabolismo , Antivirales/farmacología , Área Bajo la Curva , Genotipo , Semivida , Hepacivirus/efectos de los fármacos , Hepacivirus/genética , Indoles/metabolismo , Indoles/farmacología , Curva ROC , Ratas , Relación Estructura-Actividad , Proteínas no Estructurales Virales/metabolismoRESUMEN
Herein we describe our research efforts around the aryl and heteroaryl substitutions at the aminal carbon of the tetracyclic indole-based HCV NS5A inhibitor MK-8742. A series of potent NS5A inhibitors are described, such as compounds 45-47, 54, 56, and 65, which showed improved potency against clinically relevant and resistance associated HCV variants. The improved potency profiles of these compounds demonstrated an SAR that can improve the potency against GT2b, GT1a Y93H, and GT1a L31V altogether, which was unprecedented in our previous efforts in NS5A inhibition.
Asunto(s)
Antivirales/farmacología , Benzofuranos/farmacología , Hepacivirus/efectos de los fármacos , Imidazoles/farmacología , Proteínas no Estructurales Virales/antagonistas & inhibidores , Animales , Antivirales/síntesis química , Antivirales/química , Benzofuranos/síntesis química , Benzofuranos/química , Relación Dosis-Respuesta a Droga , Imidazoles/síntesis química , Imidazoles/química , Masculino , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Ratas , Ratas Sprague-Dawley , Relación Estructura-ActividadRESUMEN
HCV NS5A inhibitors have demonstrated impressive in vitro potency profiles in HCV replicon assays and robust HCV RNA titer reduction in the clinic making them attractive components for inclusion in an all oral fixed dose combination regimen for the treatment of HCV infection. Herein we describe our continued research efforts around the alkyl "Z group" modification of the tetracyclic indole-based NS5A inhibitor MK-8742, which led to the discovery of a series of potent NS5A inhibitors. Compounds 10 and 19 are of particular interests since they are as potent as our previous leads and have much improved rat pharmacokinetic profiles.
Asunto(s)
Antivirales/farmacología , Benzofuranos/farmacología , Hepacivirus/efectos de los fármacos , Imidazoles/farmacología , Proteínas no Estructurales Virales/antagonistas & inhibidores , Animales , Antivirales/síntesis química , Antivirales/química , Benzofuranos/síntesis química , Benzofuranos/química , Relación Dosis-Respuesta a Droga , Hepatitis C/tratamiento farmacológico , Imidazoles/síntesis química , Imidazoles/química , Masculino , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Ratas , Ratas Sprague-Dawley , Relación Estructura-Actividad , Replicación Viral/efectos de los fármacosRESUMEN
HCV NS5A inhibitors have demonstrated impressive in vitro virologic profiles in HCV replicon assays and robust HCV RNA titer reduction in the clinic making them attractive components for inclusion in an all oral fixed-dose combination (FDC) regimen for the treatment of HCV infection. Merck's effort in this area identified MK-4882 and MK-8325 as early development leads. Herein, we describe the discovery of potent macrocyclic NS5A inhibitors bearing the MK-8325 or MK-4882 core structure.
Asunto(s)
Antivirales/farmacología , Descubrimiento de Drogas , Hepacivirus/efectos de los fármacos , Compuestos Heterocíclicos de 4 o más Anillos/farmacología , Compuestos Macrocíclicos/farmacología , Proteínas no Estructurales Virales/antagonistas & inhibidores , Antivirales/síntesis química , Antivirales/química , Relación Dosis-Respuesta a Droga , Hepatitis C/tratamiento farmacológico , Compuestos Heterocíclicos de 4 o más Anillos/síntesis química , Compuestos Heterocíclicos de 4 o más Anillos/química , Compuestos Macrocíclicos/síntesis química , Compuestos Macrocíclicos/química , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Relación Estructura-Actividad , Replicación Viral/efectos de los fármacosRESUMEN
HCV NS5A inhibitors have demonstrated impressive in vitro potency profiles in HCV replicon assays and robust HCV RNA titer reduction in the clinic making them attractive components for inclusion in an all oral fixed dose combination regimen for the treatment of HCV infection. Herein, we describe research efforts that led to the discovery of a series of fused tricyclic core containing HCV NS5A inhibitors such as 24, 39, 40, 43, and 44 which have pan-genotype activity and are orally bioavailable in the rat.
Asunto(s)
Antivirales/farmacología , Descubrimiento de Drogas , Hepacivirus/efectos de los fármacos , Hepatitis C/tratamiento farmacológico , Proteínas no Estructurales Virales/antagonistas & inhibidores , Antivirales/síntesis química , Antivirales/química , Relación Dosis-Respuesta a Droga , Genotipo , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Relación Estructura-Actividad , Proteínas no Estructurales Virales/genética , Replicación Viral/efectos de los fármacosRESUMEN
HCV NS5A inhibitors have shown impressive in vitro potency profiles in HCV replicon assays thus making them attractive components for inclusion in an all oral fixed dose combination treatment regimen. Herein we describe the research efforts that led to the discovery of silyl proline containing HCV NS5A inhibitors such as 7e and 8a with pan-genotype activity profile and acceptable pharmacokinetic properties.
Asunto(s)
Antivirales/química , Antivirales/farmacología , Descubrimiento de Drogas , Hepacivirus/efectos de los fármacos , Hepacivirus/genética , Prolina/análogos & derivados , Silanos/química , Proteínas no Estructurales Virales/antagonistas & inhibidores , Antivirales/síntesis química , Relación Dosis-Respuesta a Droga , Genotipo , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Silanos/farmacología , Relación Estructura-Actividad , Proteínas no Estructurales Virales/genética , Replicación Viral/efectos de los fármacosRESUMEN
Starting from indole-based hepatitis C virus (HCV) NS5B polymerase inhibitor lead compound 1, structure modifications were performed at multiple indole substituents to improve potency and pharmacokinetic (PK) properties. Bicyclic quinazolinone was found to be the best substituent at indole nitrogen, while 4,5-furanylindole was identified as the best core. Compound 11 demonstrated excellent potency. Its C2 N,N-dimethylaminoethyl ester prodrug 12 (SCH 900188) demonstrated significant improvement in PK and was selected as the development candidate.
RESUMEN
The structure-human CXCR3 binding affinity relationship of a series of pyridyl/pyrazinyl-piperazinyl-piperidine derivatives were explored with a focus to improve PK, hERG and metabolic profiles. Several small heterocycles were identified as amide surrogates, which minimized many potential metabolite issues. During the course of SAR development, we have observed the additive effect of desirable functional groups to improve hERG and PK profiles which lead to the discovery of many clinically developable CXCR3 antagonists with excellent overall profile.
Asunto(s)
Amidas/farmacología , Descubrimiento de Drogas , Canales de Potasio Éter-A-Go-Go/metabolismo , Compuestos Heterocíclicos/farmacología , Receptores CXCR3/antagonistas & inhibidores , Amidas/administración & dosificación , Amidas/química , Animales , Relación Dosis-Respuesta a Droga , Compuestos Heterocíclicos/administración & dosificación , Compuestos Heterocíclicos/química , Humanos , Estructura Molecular , Ratas , Relación Estructura-ActividadRESUMEN
HCV infections are the leading causes for hepatocellular carcinoma and liver transplantation in the United States. Recent advances in drug discovery have identified direct acting antivirals which have significantly improved cure rates in patients. Current efforts are directed towards identification of novel direct acting antiviral targeting different mechanism of actions which could become part of all oral therapies. We recently disclosed the identification of a novel tricyclic indole derived inhibitors of HCV NS5B polymerase that bound to the enzyme close to the active site. In this manuscript we describe further optimization of potency and pharmacokinetics (PK) of these inhibitors to identify compounds in low nM potency against gt-1b. These analogs also demonstrate excellent PK in rats and monkeys when administered as a dimethyl ethyl amino ester prodrug.
Asunto(s)
Ésteres/farmacocinética , Hepacivirus/efectos de los fármacos , Indoles/farmacocinética , Proteínas no Estructurales Virales/antagonistas & inhibidores , Administración Oral , Animales , Descubrimiento de Drogas , Ésteres/química , Haplorrinos , Hepacivirus/enzimología , Humanos , Indoles/química , Profármacos/farmacología , Ratas , Relación Estructura-ActividadRESUMEN
The discovery of lead compound 2e was described. Its covalent binding to HCV NS5B polymerase enzyme was investigated by X-ray analysis. The results of distribution, metabolism and pharmacokinetics were reported. Compound 2e was demonstrated to be potent (replicon GT-1b EC50 = 0.003 µM), highly selective, and safe in in vitro and in vivo assays.
Asunto(s)
Inhibidores Enzimáticos/química , Hepacivirus/enzimología , Indoles/química , Quinolinas/química , Proteínas no Estructurales Virales/antagonistas & inhibidores , Animales , Cristalografía por Rayos X , Perros , Evaluación Preclínica de Medicamentos , Activación Enzimática/efectos de los fármacos , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacocinética , Inhibidores Enzimáticos/farmacología , Haplorrinos , Humanos , Indoles/síntesis química , Indoles/farmacocinética , Indoles/farmacología , Masculino , Simulación de Dinámica Molecular , Unión Proteica , Estructura Terciaria de Proteína , Quinolinas/síntesis química , Quinolinas/farmacocinética , Quinolinas/farmacología , Ratas , Ratas Sprague-Dawley , Proteínas no Estructurales Virales/metabolismoRESUMEN
A novel series of benzimidazolone-containing histamine H3-receptor antagonists were prepared and their structure-activity relationship was explored. These benzimidazolone analogs demonstrate potent H3-receptor binding affinities, no P450 enzyme inhibition, and strong H3 functional activity. Compound 1o exhibits the best overall profile with H3Ki=0.95nM and rat AUC=12.9µMh.
Asunto(s)
Bencimidazoles/química , Bencimidazoles/farmacología , Antagonistas de los Receptores Histamínicos H3/química , Antagonistas de los Receptores Histamínicos H3/farmacología , Animales , Bencimidazoles/síntesis química , Bencimidazoles/farmacocinética , Sistema Enzimático del Citocromo P-450/metabolismo , Cobayas , Antagonistas de los Receptores Histamínicos H3/síntesis química , Antagonistas de los Receptores Histamínicos H3/farmacocinética , Humanos , Ratas , Receptores Histamínicos H3/metabolismo , Relación Estructura-ActividadRESUMEN
The characterization of HCV genome has identified various vital functional proteins involved in the life cycle of hepatitis C virus. This has resulted in many novel enzymatic targets that are potential for development of therapeutic agents. The HCV RNA dependent RNA polymerase (HCV NS5B) is one such essential enzyme for HCV replication that has been well characterized and studied by various groups to develop novel therapies for hepatitis C. In this paper, we describe our efforts towards the identification and structure-activity relationship (SAR) of novel tricyclic indole derivatives that bind close to the palm site of the NS5B polymerase. X-ray crystal structure of an inhibitor bound to the polymerase is also described.
Asunto(s)
Antivirales/química , Antivirales/farmacología , Hepacivirus/enzimología , Indoles/química , Indoles/farmacología , ARN Polimerasa Dependiente del ARN/antagonistas & inhibidores , Sitios de Unión , Cristalografía por Rayos X , Hepacivirus/química , Hepatitis C/tratamiento farmacológico , Hepatitis C/virología , Humanos , Simulación del Acoplamiento Molecular , ARN Polimerasa Dependiente del ARN/química , ARN Polimerasa Dependiente del ARN/metabolismo , Relación Estructura-ActividadRESUMEN
BACKGROUND: The CXCR3 receptor and its three interferon-inducible ligands (CXCL9, CXCL10 and CXCL11) have been implicated as playing a central role in directing a Th1 inflammatory response. Recent studies strongly support that the CXCR3 receptor is a very attractive therapeutic target for treating autoimmune diseases, such as rheumatoid arthritis, multiple sclerosis and psoriasis, and to prevent transplant rejection. We describe here the in vitro and in vivo pharmacological characterizations of a novel and potent small molecule CXCR3 antagonist, SCH 546738. RESULTS: In this study, we evaluated in vitro pharmacological properties of SCH 546738 by radioligand receptor binding and human activated T cell chemotaxis assays. In vivo efficacy of SCH 546738 was determined by mouse collagen-induced arthritis, rat and mouse experimental autoimmune encephalomyelitis, and rat cardiac transplantation models. We show that SCH 546738 binds to human CXCR3 with a high affinity of 0.4 nM. In addition, SCH 546738 displaces radiolabeled CXCL10 and CXCL11 from human CXCR3 with IC50 ranging from 0.8 to 2.2 nM in a non-competitive manner. SCH 546738 potently and specifically inhibits CXCR3-mediated chemotaxis in human activated T cells with IC90 about 10 nM. SCH 546738 attenuates the disease development in mouse collagen-induced arthritis model. SCH 546738 also significantly reduces disease severity in rat and mouse experimental autoimmune encephalomyelitis models. Furthermore, SCH 546738 alone achieves dose-dependent prolongation of rat cardiac allograft survival. Most significantly, SCH 546738 in combination with CsA supports permanent engraftment. CONCLUSIONS: SCH 546738 is a novel, potent and non-competitive small molecule CXCR3 antagonist. It is efficacious in multiple preclinical disease models. These results demonstrate that therapy with CXCR3 antagonists may serve as a new strategy for treatment of autoimmune diseases, including rheumatoid arthritis and multiple sclerosis, and to prevent transplant rejection.
Asunto(s)
Enfermedades Autoinmunes/tratamiento farmacológico , Quimiotaxis de Leucocito/efectos de los fármacos , Rechazo de Injerto/prevención & control , Supervivencia de Injerto/efectos de los fármacos , Trasplante de Corazón , Piperazinas/farmacología , Pirazinamida/análogos & derivados , Receptores CXCR3/antagonistas & inhibidores , Linfocitos T/efectos de los fármacos , Animales , Artritis Experimental/tratamiento farmacológico , Artritis Experimental/inmunología , Artritis Reumatoide/tratamiento farmacológico , Artritis Reumatoide/inmunología , Enfermedades Autoinmunes/inmunología , Quimiotaxis de Leucocito/inmunología , Modelos Animales de Enfermedad , Encefalomielitis Autoinmune Experimental/tratamiento farmacológico , Encefalomielitis Autoinmune Experimental/inmunología , Rechazo de Injerto/inmunología , Humanos , Técnicas In Vitro , Ratones , Esclerosis Múltiple/tratamiento farmacológico , Esclerosis Múltiple/inmunología , Unión Proteica , Pirazinamida/farmacología , Ensayo de Unión Radioligante , Ratas , Linfocitos T/inmunologíaRESUMEN
The synthesis of substituted 3,4-dihydrofuranoindoles is reported. These new indole compounds were used to synthesize potent HCV NS5B inhibitors. The binding mode of the dihydrofuranoindole-derived inhibitors was established via X-ray crystallographic studies.
Asunto(s)
Inhibidores Enzimáticos/síntesis química , Hepacivirus/efectos de los fármacos , Indoles/síntesis química , ARN Polimerasa Dependiente del ARN/antagonistas & inhibidores , Proteínas no Estructurales Virales/antagonistas & inhibidores , Inhibidores Enzimáticos/farmacología , Hepacivirus/enzimología , Indoles/farmacología , Modelos Moleculares , Dominios y Motivos de Interacción de ProteínasRESUMEN
Starting from indole-based C-3 pyridone HCV NS5B polymerase inhibitor 2, structure-activity relationship (SAR) investigations of the indole N-1 benzyl moiety were performed. This study led to the discovery of irreversible inhibitors with p-fluoro-sulfone- or p-fluoro-nitro-substituted N-1 benzyl groups which achieved breakthrough replicon assay potency (EC(50) = 1 nM). The formation of a covalent bond with adjacent cysteine-366 thiol was was proved by mass spectroscopy and X-ray crystal structure studies. The C-5 ethyl C-2 carboxylic acid derivative 47 had an excellent oral area-under-the-curve (AUC) of 18 µM·h (10 mg/kg). Its oral exposure in monkeys and dogs was also very good. The NMR ALARM assay, mass spectroscopy experiments, in vitro counter screening, and toxicology assays demonstrated that the covalent bond formation between compound 47 and the protein was highly selective and specific. The overall excellent profile of 47 made it an interesting candidate for further investigation.
Asunto(s)
Antivirales/síntesis química , Hepacivirus/efectos de los fármacos , Indoles/síntesis química , Nitrocompuestos/síntesis química , Sulfonas/síntesis química , Proteínas no Estructurales Virales/antagonistas & inhibidores , Animales , Antivirales/farmacocinética , Antivirales/farmacología , Cristalografía por Rayos X , Perros , Haplorrinos , Hepacivirus/enzimología , Indoles/farmacocinética , Indoles/farmacología , Modelos Moleculares , Estructura Molecular , Pruebas de Mutagenicidad , Nitrocompuestos/farmacocinética , Nitrocompuestos/farmacología , Piridonas/síntesis química , Piridonas/farmacocinética , Piridonas/farmacología , Ratas , Relación Estructura-Actividad , Sulfonas/farmacocinética , Sulfonas/farmacologíaRESUMEN
Starting with the indole-based C-3 pyridone lead HCV polymerase inhibitor 2, extensive SAR studies were performed at different positions of the indole core. The best C-5 groups were found to be compact and nonpolar moieties and that the C-6 attachments were not affecting potency. Limited N-1 benzyl-type substituent studies indicated that the best substitutions were fluoro or methyl groups at 2' or 5' positions of the benzyl group. To improve pharmacokinetic (PK) properties, acylsulfonamides were incorporated as acid isosteres at the C-2 position. Further optimization of the combination at N-1, C-2, C-5, and C-6 resulted in the identification of compound 56, which had an excellent potency in both NS5B enzyme (IC(50) = 0.008 µM) and cell-based replicon (EC(50) = 0.02 µM) assays and a good oral PK profile with area-under-the curve (AUC) of 14 and 8 µM·h in rats and dogs, respectively. X-ray structure of inhibitor 56 bound to the enzyme was also reported.