RESUMEN
MK-4256, a tetrahydro-ß-carboline sstr3 antagonist, was discontinued due to a cardiovascular (CV) adverse effect observed in dogs. Additional investigations revealed that the CV liability (QTc prolongation) was caused by the hERG off-target activity of MK-4256 and was not due to sstr3 antagonism. In this Letter, we describe our extensive SAR effort at the C3 position of the tetrahydro-ß-carboline structure. This effort resulted in identification of 5-fluoro-pyridin-2-yl as the optimal substituent on the imidazole ring to balance sstr3 activity and the hERG off-target liability.
Asunto(s)
Carbolinas/química , Carbolinas/farmacología , Receptores de Somatostatina/antagonistas & inhibidores , Animales , Carbolinas/síntesis química , Perros , Relación Dosis-Respuesta a Droga , Humanos , Ratones , Estructura Molecular , Ratas , Relación Estructura-ActividadRESUMEN
We report SAR studies on a novel non-peptidic bombesin receptor subtype-3 (BRS-3) agonist lead series derived from high-throughput screening hit RY-337. This effort led to the discovery of compound 22e with significantly improved potency at both rodent and human BRS-3.
Asunto(s)
Descubrimiento de Drogas , Imidazoles/química , Imidazoles/farmacología , Receptores de Bombesina/agonistas , Animales , Disponibilidad Biológica , Humanos , Imidazoles/farmacocinética , Ratas , Relación Estructura-ActividadRESUMEN
This Letter describes a series of potent and selective BRS-3 agonists containing a biarylethylimidazole pharmacophore. Extensive SAR studies were carried out with different aryl substitutions. This work led to the identification of a compound 2-{2-[4-(pyridin-2-yl)phenyl]ethyl}-5-(2,2-dimethylbutyl)-1H-imidazole 9 with excellent binding affinity (IC(50)=18 nM, hBRS-3) and functional agonist activity (EC(50)=47 nM, 99% activation). After oral administration, compound 9 had sufficient exposure in diet induced obese mice to demonstrate efficacy in lowering food intake and body weight via BRS-3 activation.
Asunto(s)
Imidazoles/química , Imidazoles/uso terapéutico , Obesidad/tratamiento farmacológico , Receptores de Bombesina/agonistas , Receptores de Bombesina/metabolismo , Animales , Peso Corporal/efectos de los fármacos , Ingestión de Alimentos/efectos de los fármacos , Humanos , Imidazoles/farmacocinética , Ratones , Ratas , Relación Estructura-ActividadRESUMEN
We report the design, synthesis and properties of spiroindane based compound 1, a potent, selective, orally bioavailable, non-peptide melanocortin subtype-4 receptor agonist. Compound 1 shows excellent erectogenic activity in the rodent models.
Asunto(s)
Disfunción Eréctil/tratamiento farmacológico , Indanos/química , Indanos/uso terapéutico , Receptor de Melanocortina Tipo 4/agonistas , Receptor de Melanocortina Tipo 4/metabolismo , Compuestos de Espiro/química , Compuestos de Espiro/uso terapéutico , Animales , Células CHO , Cricetinae , Cricetulus , Perros , Haplorrinos , Humanos , Indanos/farmacocinética , Indanos/farmacología , Masculino , Ratones , Estructura Molecular , Unión Proteica , Ratas , Compuestos de Espiro/farmacocinética , Compuestos de Espiro/farmacología , Relación Estructura-ActividadRESUMEN
Design, syntheses and structure-activity relationships of N-acetylated piperazine privileged structures containing MC4R agonist compounds were described. The most potent derivatives were low nM MC4R selective full agonists. Several compounds from the series had modest pharmacokinetic properties.
Asunto(s)
Ligandos , Receptor de Melanocortina Tipo 4/agonistas , Animales , Humanos , Piperazina , Piperazinas/síntesis química , Piperazinas/química , Piperazinas/farmacocinética , Ratas , Ratas Sprague-Dawley , Receptor de Melanocortina Tipo 4/metabolismo , Relación Estructura-ActividadRESUMEN
We report a series of potent and selective MC4R agonists based on spiroindane amide privileged structures for potential treatments of obesity. Among the synthetic methods used, Method C allows rapid synthesis of the analogs. The series of compounds can afford high potency on MC4R as well as good rodent pharmacokinetic profiles. Compound 1r (MK-0489) demonstrates MC4R mediated reduction of food intake and body weight in mouse models. Compound 1r is efficacious in 14-day diet-induced obese (DIO) rat models.
Asunto(s)
Amidas/química , Fármacos Antiobesidad/química , Obesidad/tratamiento farmacológico , Pirrolidinas/química , Receptor de Melanocortina Tipo 4/agonistas , Compuestos de Espiro/química , Amidas/farmacocinética , Amidas/uso terapéutico , Animales , Fármacos Antiobesidad/farmacocinética , Fármacos Antiobesidad/uso terapéutico , Peso Corporal/efectos de los fármacos , Humanos , Ratones , Ratones Noqueados , Pirrolidinas/farmacocinética , Pirrolidinas/uso terapéutico , Ratas , Ratas Sprague-Dawley , Receptor de Melanocortina Tipo 4/metabolismo , Compuestos de Espiro/farmacocinética , Compuestos de Espiro/uso terapéutico , Relación Estructura-ActividadRESUMEN
Design, synthesis, and SAR of a series of 3H-spiro[isobenzofuran-1,4'-piperidine] based compounds as potent, selective and orally bioavailable melanocortin subtype-4 receptor (MC4R) agonists are disclosed.
Asunto(s)
Piperidinas/química , Receptor de Melanocortina Tipo 4/agonistas , Administración Oral , Animales , Encéfalo/metabolismo , Cristalografía por Rayos X , Evaluación Preclínica de Medicamentos , Humanos , Conformación Molecular , Piperidinas/síntesis química , Piperidinas/farmacología , Ratas , Ratas Sprague-Dawley , Receptor de Melanocortina Tipo 4/metabolismo , Compuestos de Espiro/química , Relación Estructura-ActividadRESUMEN
We report an SAR study of MC4R analogs containing spiroindane heterocyclic privileged structures. Compound 26 with N-Me-1,2,4-triazole moiety possesses exceptional potency at MC4R and potent anti-obesity efficacy in a mouse model. However, the efficacy is not completely mediated through MC4R. Additional SAR studies led to the discovery of compound 32, which is more potent at MC4R. Compound 32 demonstrates MC4R mediated anti-obesity efficacy in rodent models.
Asunto(s)
Obesidad/tratamiento farmacológico , Receptor de Melanocortina Tipo 4/agonistas , Triazoles/farmacología , Animales , Cromatografía Líquida de Alta Presión , Modelos Animales de Enfermedad , Ratones , Ratones Noqueados , Estructura Molecular , Ratas , Receptor de Melanocortina Tipo 4/genética , Relación Estructura-Actividad , Triazoles/química , Triazoles/uso terapéuticoRESUMEN
The imidazolyl-tetrahydro-ß-carboline class of sstr3 antagonists have demonstrated efficacy in a murine model of glucose excursion and may have potential as a treatment for type 2 diabetes. The first candidate in this class caused unacceptable QTc interval prolongation in oral, telemetrized cardiovascular (CV) dogs. Herein, we describe our efforts to identify an acceptable candidate without CV effects. These efforts resulted in the identification of (1R,3R)-3-(4-(5-fluoropyridin-2-yl)-1H-imidazol-2-yl)-1-(1-ethyl-pyrazol-4-yl)-1-(3-methyl-1,3,4-oxadiazol-3H-2-one-5-yl)-2,3,4,9-tetrahydro-1H-ß-carboline (17e, MK-1421).
RESUMEN
Antagonism of somatostatin subtype receptor 3 (sstr3) has emerged as a potential treatment of Type 2 diabetes. Unfortunately, the development of our first preclinical candidate, MK-4256, was discontinued due to a dose-dependent QTc (QT interval corrected for heart rate) prolongation observed in a conscious cardiovascular (CV) dog model. As the fate of the entire program rested on resolving this issue, it was imperative to determine whether the observed QTc prolongation was associated with hERG channel (the protein encoded by the human Ether-à-go-go-Related Gene) binding or was mechanism-based as a result of antagonizing sstr3. We investigated a structural series containing carboxylic acids to reduce the putative hERG off-target activity. A key tool compound, 3A, was identified from this SAR effort. As a potent sstr3 antagonist, 3A was shown to reduce glucose excursion in a mouse oGTT assay. Consistent with its minimal hERG activity from in vitro assays, 3A elicited little to no effect in an anesthetized, vagus-intact CV dog model at high plasma drug levels. These results afforded the critical conclusion that sstr3 antagonism is not responsible for the QTc effects and therefore cleared a path for the program to progress.
RESUMEN
This letter provides the first pharmacological proof of principle that the sst3 receptor mediates glucose-stimulated insulin secretion (GSIS) from pancreatic ß-cells. To enable these studies, we identified the selective sst3 antagonist (1R,3R)-3-(5-phenyl-1H-imidazol-2-yl)-1-(tetrahydro-2H-pyran-4-yl)-2,3,4,9-tetrahydro-1H-ß-carboline (5a), with improved ion channel selectivity and mouse pharmacokinetic properties as compared to previously described tetrahydro-ß-carboline imidazole sst3 antagonists. We demonstrated that compound 5a enhances GSIS in pancreatic ß-cells and blocks glucose excursion induced by dextrose challenge in ipGTT and OGTT models in mice. Finally, we provided strong evidence that these effects are mechanism-based in an ipGTT study, showing reduction of glucose excursion in wild-type but not sst3 knockout mice. Thus, we have shown that antagonism of sst3 represents a new mechanism with potential in treating type 2 diabetes mellitus.
RESUMEN
A structure-activity relationship study of the imidazolyl-ß-tetrahydrocarboline series identified MK-4256 as a potent, selective SSTR3 antagonist, which demonstrated superior efficacy in a mouse oGTT model. MK-4256 reduced glucose excursion in a dose-dependent fashion with maximal efficacy achieved at doses as low as 0.03 mg/kg po. As compared with glipizide, MK-4256 showed a minimal hypoglycemia risk in mice.
RESUMEN
Bombesin receptor subtype 3 (BRS-3) is a G protein coupled receptor whose natural ligand is unknown. We developed potent, selective agonist (Bag-1, Bag-2) and antagonist (Bantag-1) ligands to explore BRS-3 function. BRS-3-binding sites were identified in the hypothalamus, caudal brainstem, and several midbrain nuclei that harbor monoaminergic cell bodies. Antagonist administration increased food intake and body weight, whereas agonists increased metabolic rate and reduced food intake and body weight. Prolonged high levels of receptor occupancy increased weight loss, suggesting a lack of tachyphylaxis. BRS-3 agonist effectiveness was absent in Brs3(-/Y) (BRS-3 null) mice but was maintained in Npy(-/-)Agrp(-/-), Mc4r(-/-), Cnr1(-/-), and Lepr(db/db) mice. In addition, Brs3(-/Y) mice lost weight upon treatment with either a MC4R agonist or a CB1R inverse agonist. These results demonstrate that BRS-3 has a role in energy homeostasis that complements several well-known pathways and that BRS-3 agonists represent a potential approach to the treatment of obesity.