RESUMEN
Oral phosphodiesterase (PDE) 4 inhibitors such as roflumilast have established the potential of PDE4 inhibition for the treatment of respiratory diseases. However, PDE4 inhibitor efficacy is limited by mechanism-related side effects such as emesis and nausea. Delivering the inhibitor by the inhaled route may improve therapeutic index, and we describe 6-({3-[(dimethylamino)carbonyl]phenyl}sulfonyl)-8-methyl-4-{[3-methyloxy) phenyl]amino}-3-quinolinecarboxamide (GSK256066), an exceptionally high-affinity inhibitor of PDE4 designed for inhaled administration. GSK256066 is a slow and tight binding inhibitor of PDE4B (apparent IC(50) 3.2 pM; steady-state IC(50) <0.5 pM), which is more potent than any previously documented compound, for example, roflumilast (IC(50) 390 pM), tofimilast (IC(50) 1.6 nM), and cilomilast (IC(50) 74 nM). Consistent with this, GSK256066 inhibited tumor necrosis factor α production by lipopolysaccharide (LPS)-stimulated human peripheral blood monocytes with 0.01 nM IC(50) (compared with IC(50) values of 5, 22, and 389 nM for roflumilast, tofimilast, and cilomilast, respectively) and by LPS-stimulated whole blood with 126 pM IC(50). GSK256066 was highly selective for PDE4 (>380,000-fold versus PDE1, PDE2, PDE3, PDE5, and PDE6 and >2500-fold against PDE7), inhibited PDE4 isoforms A-D with equal affinity, and had a substantial high-affinity rolipram binding site ratio (>17). When administered intratracheally to rats, GSK256066 inhibited LPS-induced pulmonary neutrophilia with ED(50) values of 1.1 µg/kg (aqueous suspension) and 2.9 µg/kg (dry powder formulation) and was more potent than an aqueous suspension of the corticosteroid fluticasone propionate (ED(50) 9.3 µg/kg). Thus, GSK256066 has been demonstrated to have exceptional potency in vitro and in vivo and is being clinically investigated as a treatment for chronic obstructive pulmonary disease.
Asunto(s)
Aminoquinolinas/administración & dosificación , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4/metabolismo , Inhibidores de Fosfodiesterasa 4/administración & dosificación , Sulfonas/administración & dosificación , Administración por Inhalación , Aminoquinolinas/metabolismo , Aminoquinolinas/farmacocinética , Animales , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4/farmacocinética , Relación Dosis-Respuesta a Droga , Humanos , Leucocitos Mononucleares/efectos de los fármacos , Leucocitos Mononucleares/enzimología , Inhibidores de Fosfodiesterasa 4/metabolismo , Inhibidores de Fosfodiesterasa 4/farmacocinética , Unión Proteica/fisiología , Ratas , Ratas Sprague-Dawley , Sulfonas/metabolismo , Sulfonas/farmacocinéticaRESUMEN
Following the discovery of 4-(substituted amino)-1-alkyl-pyrazolo[3,4-b]pyridine-5-carboxamides as potent and selective phosphodiesterase 4B inhibitors, [Hamblin, J. N.; Angell, T.; Ballentine, S., et al. Bioorg. Med. Chem. Lett.2008, 18, 4237] the SAR of the 5-position was investigated further. A range of substituted heterocycles showed good potencies against PDE4. Optimisation using X-ray crystallography and computational modelling led to the discovery of 16, with sub-nM inhibition of LPS-induced TNF-α production from isolated human peripheral blood mononuclear cells.
Asunto(s)
Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4/química , Compuestos Heterocíclicos/química , Inhibidores de Fosfodiesterasa/química , Pirazoles/química , Piridinas/química , Sitios de Unión , Simulación por Computador , Cristalografía por Rayos X , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4/metabolismo , Humanos , Modelos Químicos , Modelos Moleculares , Inhibidores de Fosfodiesterasa/síntesis química , Inhibidores de Fosfodiesterasa/farmacología , Estructura Terciaria de Proteína , Pirazoles/síntesis química , Pirazoles/farmacología , Piridinas/síntesis química , Piridinas/farmacología , Relación Estructura-Actividad , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Clinical utility of phosphodiesterase 4 (PDE4) inhibitors as anti-inflammatory agents has, to date, been limited by adverse effects including nausea and emesis, making accurate assessment of emetic versus anti-inflammatory potencies critical to the development of inhibitors with improved therapeutic indices. In the present study we determined the in vitro and in vivo anti-inflammatory potencies of the first-generation PDE4 inhibitor, rolipram, the second-generation inhibitors, roflumilast and cilomilast, and a novel third generation inhibitor, 1-ethyl-5-{5-[(4-methyl-1-piperazinyl)methyl]-1,3,4-oxadiazol-2-yl}-N-(tetrahydro-2H-pyran-4-yl)-1H-pyrazolo[3,4-b]pyridin-4-amine (EPPA-1). The rank-order potency against lipopolysaccharide (LPS)-induced tumor necrosis factor-alpha production by human peripheral blood mononuclear cells was roflumilast (IC(50) = 5 nM) > EPPA-1 (38) > rolipram (269) > cilomilast (389), and against LPS-induced pulmonary neutrophilia in the rat was EPPA-1 (D(50) = 0.042 mg/kg) > roflumilast (0.24) > rolipram (3.34) > cilomilast (4.54). Pica, the consumption of non-nutritive substances in response to gastrointestinal stress, was used as a surrogate measure for emesis, giving a rank-order potency of rolipram (D(50) = 0.495 mg/kg) > roflumilast (1.6) > cilomilast (6.4) > EPPA-1 (24.3). The low and high emetogenic activities of EPPA-1 and rolipram, respectively, detected in the pica model were confirmed in a second surrogate model of emesis, reversal of alpha(2)-adrenoceptor-mediated anesthesia in the mouse. The rank order of therapeutic indices derived in the rat [(pica D(50))/(neutrophilia D(50))] was EPPA-1 (578) > roflumilast (6.4) > cilomilast (1.4) > rolipram (0.15), consistent with the rank order derived in the ferret [(emesis D(50))/(neutrophilia D(50))]. These data validate rat pica feeding as a surrogate for PDE4 inhibitor-induced emesis in higher species, and identify EPPA-1 as a novel PDE4 inhibitor with an improved therapeutic index.
Asunto(s)
Inhibidores de Fosfodiesterasa 4 , Inhibidores de Fosfodiesterasa/farmacología , Pica/psicología , Piperazinas/farmacología , Piridinas/farmacología , Vómitos/inducido químicamente , Aminopiridinas/farmacología , Animales , Benzamidas/farmacología , Ácidos Carboxílicos/farmacología , Ácidos Ciclohexanocarboxílicos , Ciclopropanos/farmacología , Hurones , Humanos , Lipopolisacáridos/antagonistas & inhibidores , Lipopolisacáridos/toxicidad , Ratones , Ratones Endogámicos C57BL , Neutrófilos/efectos de los fármacos , Nitrilos/farmacología , Pica/inducido químicamente , Ratas , Ratas Endogámicas Lew , Receptores Adrenérgicos alfa 2/efectos de los fármacos , Receptores Adrenérgicos alfa 2/fisiología , Rolipram/farmacología , Factor de Necrosis Tumoral alfa/antagonistas & inhibidoresRESUMEN
Crystallography-driven optimisation of a lead derived from similarity searching of the GSK compound collection resulted in the discovery of a series of quinoline derivatives that were highly potent and selective inhibitors of PDE4 with a good pharmacokinetic profile in the rat. Quinolines 43 and 48 have potential as oral medicines for the treatment of COPD.
Asunto(s)
Inhibidores de Fosfodiesterasa 4 , Inhibidores de Fosfodiesterasa/administración & dosificación , Inhibidores de Fosfodiesterasa/química , Quinolinas/administración & dosificación , Quinolinas/química , Administración Oral , Animales , Bovinos , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4/metabolismo , Humanos , Masculino , Estructura Secundaria de Proteína , Estructura Terciaria de Proteína , Ratas , Ratas Sprague-Dawley , Relación Estructura-ActividadRESUMEN
Many years of work have been invested in the identification of potent and selective COX-2 inhibitors for the treatment of chronic inflammatory pain. One issue faced by workers is the balance between the lipophilicity required for potent enzyme inhibition and the physical properties necessary for drug absorption and distribution in vivo. Frequently approaches to reduce lipophilicity through introduction of polar functionality is hampered by highly challenging chemistry to prepare key molecules. We have complemented traditional synthetic chemistry with a biotransformations approach which efficiently provided access to an array of key target molecules.
Asunto(s)
Inhibidores de la Ciclooxigenasa 2/síntesis química , Biotransformación , Química Farmacéutica/métodos , Ciclooxigenasa 2/química , Inhibidores de la Ciclooxigenasa 2/farmacología , Diseño de Fármacos , Humanos , Inflamación/tratamiento farmacológico , Concentración 50 Inhibidora , Modelos Químicos , Estructura Molecular , Relación Estructura-ActividadRESUMEN
A novel series of [4-[4-(methylsulfonyl)phenyl]-6-(trifluoromethyl)-2-pyrimidine-based cyclooxygenase-2 (COX-2) inhibitors, which have a different arrangement of substituents compared to the more common 1,2-diarylheterocycle based molecules, have been discovered. For example, 2-(butyloxy)-4-[4-(methylsulfonyl)phenyl]-6-(trifluoromethyl)pyrimidine (47), a member of the 2-pyrimidinyl ether series, has been shown to be a potent and selective inhibitor with a favourable pharmacokinetic profile, high brain penetration and good efficacy in rat models of hypersensitivity.
Asunto(s)
Aminas/síntesis química , Inhibidores de la Ciclooxigenasa 2/síntesis química , Éteres/síntesis química , Pirimidinas/síntesis química , Sulfonas/síntesis química , Aminas/farmacología , Animales , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Química Farmacéutica/métodos , Ciclooxigenasa 2/química , Inhibidores de la Ciclooxigenasa 2/farmacología , Modelos Animales de Enfermedad , Diseño de Fármacos , Éteres/farmacología , Humanos , Inflamación , Concentración 50 Inhibidora , Ratones , Estructura Molecular , Enfermedades Neurodegenerativas/tratamiento farmacológico , Pirimidinas/farmacología , Ratas , Sulfonas/farmacologíaRESUMEN
Crystallography driven optimisation of a lead derived from similarity searching of the GSK compound collection resulted in the discovery of quinoline-3-carboxamides as highly potent and selective inhibitors of phosphodiesterase 4B. This series has been optimized to GSK256066, a potent PDE4B inhibitor which also inhibits LPS induced production of TNF-alpha from isolated human peripheral blood mononuclear cells with a pIC(50) of 11.1. GSK256066 also has a suitable profile for inhaled dosing.
Asunto(s)
Antiinflamatorios/química , Inhibidores de Fosfodiesterasa 4 , Inhibidores de Fosfodiesterasa/química , Quinolinas/química , Administración por Inhalación , Animales , Antiinflamatorios/síntesis química , Antiinflamatorios/farmacocinética , Sitios de Unión , Dominio Catalítico , Cristalografía por Rayos X , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4/metabolismo , Humanos , Leucocitos Mononucleares/metabolismo , Lipopolisacáridos/farmacología , Inhibidores de Fosfodiesterasa/síntesis química , Inhibidores de Fosfodiesterasa/farmacocinética , Quinolinas/síntesis química , Quinolinas/farmacocinética , Ratas , Relación Estructura-Actividad , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Optimisation of a high-throughput screening hit resulted in the discovery of 4-(substituted amino)-1-alkyl-pyrazolo[3,4-b]pyridine-5-carboxamides as potent and selective inhibitors of Phosphodiesterase 4 (PDE4). Herein, we describe early SAR studies around this novel template highlighting preferred substituents and rationalization of SAR through X-ray crystal structures of analogues bound to the PDE4 active site. Pyrazolopyridine 20a was found to be a potent and selective PDE4 inhibitor which also inhibits LPS induced TNF-alpha production from isolated human peripheral blood mononuclear cells and has an encouraging rat PK profile suitable for oral dosing.
Asunto(s)
Química Farmacéutica/métodos , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4/química , Inhibidores de Fosfodiesterasa 4 , Pirazoles/síntesis química , Pirazoles/farmacocinética , Piridinas/síntesis química , Piridinas/farmacocinética , Aminopiridinas/farmacología , Animales , Benzamidas/farmacología , Cristalografía por Rayos X/métodos , Ciclopropanos/farmacología , Diseño de Fármacos , Humanos , Leucocitos Mononucleares/citología , Leucocitos Mononucleares/metabolismo , Modelos Biológicos , Modelos Químicos , Pirrolidinonas/química , Ratas , Rolipram/farmacología , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
The pathogenic form of the cyclooxygenase (COX) enzyme, COX-2, is also constitutively present in the spinal cord and has been implicated in chronic pain states in rat and man. A number of COX-2 inhibitors, including celecoxib and rofecoxib, are already used in man for the treatment of inflammatory pain. Preclinically, the dual-acting COX-2 inhibitor, GW406381X [2-(4-ethoxyphenyl)-3-[4-(methylsulfonyl)phenyl]-pyrazolo[1,5-b]pyridazine, where X denotes the free base], is as effective as rofecoxib and celecoxib in the rat established Freund's Complete Adjuvant model with an ED(50) of 1.5 mg/kg p.o. compared with 1.0 mg/kg p.o. for rofecoxib and 6.6 mg/kg p.o. for celecoxib. However, in contrast to celecoxib (5 mg/kg p.o. b.i.d.) and rofecoxib (5 mg/kg p.o. b.i.d.), which were without significant effect, GW406381X (5 mg/kg p.o. b.i.d.) fully reversed mechanical allodynia in the chronic constriction injury model and reversed thermal hyperalgesia in the mouse partial ligation model, both models of neuropathic pain. GW406381X, was also effective in a rat model of capsaicin-induced central sensitization, when given intrathecally (ED(50) = 0.07 mug) and after chronic but not acute oral dosing. Celecoxib and rofecoxib had no effect in this model. Several hypotheses have been proposed to try to explain these differences in efficacy, including central nervous system penetration, enzyme kinetics, and potency. The novel finding of effectiveness of GW406381X in these models of neuropathic pain/central sensitization, in addition to activity in inflammatory pain models and together with its central efficacy, suggests dual activity of GW406381X compared with celecoxib and rofecoxib, which may translate into greater efficacy in a broader spectrum of pain states in the clinic.
Asunto(s)
Inhibidores de la Ciclooxigenasa/uso terapéutico , Hidrocarburos Aromáticos/uso terapéutico , Nitrógeno/uso terapéutico , Dolor/tratamiento farmacológico , Animales , Encéfalo/metabolismo , Células COS , Capsaicina , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Humanos , Hidrocarburos Aromáticos/farmacocinética , Hiperalgesia/tratamiento farmacológico , Masculino , Ratones , Nitrógeno/farmacocinética , Pirazoles , Piridazinas , RatasRESUMEN
GW406381 (8), currently undergoing clinical evaluation for the treatment of inflammatory pain is a member of a novel series of 2,3-diaryl-pyrazolo[1,5-b]pyridazine based cyclooxygenase-2 (COX-2) inhibitors, which have been shown to be highly potent and selective. Several examples of the series, in addition to possessing favourable pharmacokinetic profiles and analgesic activity in vivo, have also demonstrated relatively high brain penetration in the rat compared with the clinically available compounds, which may ultimately prove beneficial in the treatment of pain.