RESUMO
The approvals of idelalisib and duvelisib have validated PI3Kδ inhibitors for the treatment for hematological malignancies driven by the PI3K/AKT pathway. Our program led to the identification of structurally distinct heterocycloalkyl purine inhibitors with excellent isoform and kinome selectivity; however, they had high projected human doses. Improved ligand contacts gave potency enhancements, while replacement of metabolic liabilities led to extended half-lives in preclinical species, affording PI3Kδ inhibitors with low once-daily predicted human doses. Treatment of C57BL/6-Foxp3-GDL reporter mice with 30 and 100 mg/kg/day of 3c (MSD-496486311) led to a 70% reduction in Foxp3-expressing regulatory T cells as observed through bioluminescence imaging with luciferin, consistent with the role of PI3K/AKT signaling in Treg cell proliferation. As a model for allergic rhinitis and asthma, treatment of ovalbumin-challenged Brown Norway rats with 0.3 to 30 mg/kg/day of 3c gave a dose-dependent reduction in pulmonary bronchoalveolar lavage inflammation eosinophil cell count.
Assuntos
Classe I de Fosfatidilinositol 3-Quinases/química , Fatores Imunológicos/química , Pirrolidinas/química , Animais , Antígenos CD/metabolismo , Antígenos de Diferenciação de Linfócitos T/metabolismo , Linfócitos B/citologia , Linfócitos B/efeitos dos fármacos , Linfócitos B/metabolismo , Sítios de Ligação , Classe I de Fosfatidilinositol 3-Quinases/metabolismo , Modelos Animais de Doenças , Cães , Meia-Vida , Humanos , Fatores Imunológicos/metabolismo , Fatores Imunológicos/farmacologia , Fatores Imunológicos/uso terapêutico , Lectinas Tipo C/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Simulação de Dinâmica Molecular , Proteínas Proto-Oncogênicas c-akt/metabolismo , Pirrolidinas/metabolismo , Pirrolidinas/farmacologia , Pirrolidinas/uso terapêutico , Ratos , Ratos Wistar , Rinite Alérgica/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Relação Estrutura-AtividadeRESUMO
PI3Kδ catalytic activity is required for immune cell activation, and has been implicated in inflammatory diseases as well as hematological malignancies in which the AKT pathway is overactive. A purine PI3Kδ inhibitor bearing a benzimidazolone-piperidine motif was found to be poorly tolerated in dog, which was attributed to diffuse vascular injury. Several strategies were implemented to mitigate this finding, including reconstruction of the benzimidazolone-piperidine selectivity motif. Structure-based design led to the identification of O- and N-linked heterocycloalkyls, with pyrrolidines being particularly ligand efficient and kinome selective, and having an improved safety pharmacology profile. A representative was advanced into a dog tolerability study where it was found to be well tolerated, with no histopathological evidence of vascular injury.
Assuntos
Classe Ia de Fosfatidilinositol 3-Quinase/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Purinas/farmacologia , Pirrolidinas/farmacologia , Animais , Cães , Desenho de Fármacos , Células HeLa , Humanos , Masculino , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/toxicidade , Purinas/síntese química , Purinas/toxicidade , Pirrolidinas/síntese química , Pirrolidinas/toxicidade , Ratos WistarRESUMO
We leveraged a clinical pharmacokinetic (PK)/pharmacodynamics (PD)/efficacy relationship established with an oral phosphatidylinositol 3-kinase (PI3K)δ inhibitor (Idelalisib) in a nasal allergen challenge study to determine whether a comparable PK/PD/efficacy relationship with PI3Kδ inhibitors was observed in preclinical respiratory models of type 2 T helper cell (TH2) and type 1 T helper cell (TH1) inflammation. Results from an in vitro rat blood basophil (CD63) activation assay were used as a PD biomarker. IC50 values for PI3Kδ inhibitors, MSD-496486311, MSD-126796721, Idelalisib, and Duvelisib, were 1.2, 4.8, 0.8, and 0.5 µM. In the ovalbumin Brown Norway TH2 pulmonary inflammation model, all PI3Kδ inhibitors produced a dose-dependent inhibition of bronchoalveolar lavage eosinophils (maximum effect between 80% and 99%). In a follow-up experiment designed to investigate PK attributes [maximum (or peak) plasma concentration (Cmax), area under the curve (AUC), time on target (ToT)] that govern PI3Kδ efficacy, MSD-496486311 [3 mg/kg every day (QD) and 100 mg/kg QD] produced 16% and 93% inhibition of eosinophils, whereas doses (20 mg/kg QD, 10 mg/kg twice per day, and 3 mg/kg three times per day) produced 54% to 66% inhibition. Our profiling suggests that impact of PI3Kδ inhibitors on eosinophils is supported by a PK target with a ToT over the course of treatment close to the PD IC50 rather than strictly driven by AUC, Cmax, or Cmin (minimum blood plasma concentration) coverage. Additional studies in an Altenaria alternata rat model, a sheep Ascaris-sensitive sheep model, and a TH1-driven rat ozone exposure model did not challenge our hypothesis, suggesting that an IC50 level of TE (target engagement) sustained for 24 hours is required to produce efficacy in these traditional models. We conclude that the PK/PD observations in our animal models appear to align with clinical results associated with a TH2 airway disease.
Assuntos
Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase/farmacologia , Inibidores de Fosfoinositídeo-3 Quinase/farmacocinética , Doenças Respiratórias/tratamento farmacológico , Doenças Respiratórias/imunologia , Células Th1/efeitos dos fármacos , Células Th2/efeitos dos fármacos , Animais , Modelos Animais de Doenças , Humanos , Inflamação/tratamento farmacológico , Inflamação/imunologia , Inflamação/metabolismo , Masculino , Inibidores de Fosfoinositídeo-3 Quinase/uso terapêutico , Ratos , Doenças Respiratórias/metabolismoRESUMO
Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) has been reported to mediate both tumorigenic and anti-tumor effects in vivo. Blockade of the CEACAM1 signaling pathway has recently been implicated as a novel mechanism for cancer immunotherapy. CC1, a mouse anti-CEACAM1 monoclonal antibody (mAb), has been widely used as a pharmacological tool in preclinical studies to inform on CEACAM1 pathway biology although limited data are available on its CEACAM1 blocking characteristics or pharmacodynamic-pharmacokinetic profiles. We sought to investigate CEACAM1 expression on mouse tumor and immune cells, characterize CC1 mAb binding, and evaluate CC1 in syngeneic mouse oncology models as a monotherapy and in combination with an anti-PD-1 mAb. CEACAM1 expression was observed at high levels on neutrophils, NK cells and myeloid-derived suppressor cells (MDSCs), while the expression on tumor-infiltrating CD8+ T cells was low. Unexpectedly, rather than blocking, CC1 facilitated binding of soluble CEACAM1 to CEACAM1 expressing cells. No anti-tumor effects were observed in CT26, MBT2 or A20 models when tested up to 30 mg/kg dose, a dose that was estimated to achieve >90% target engagement in vivo. Taken together, tumor infiltrating CD8+ T cells express low levels of CEACAM1 and CC1 Ab mediates no or minimal anti-tumor effects in vivo, as a monotherapy or in combination with anti-PD-1 treatment.
RESUMO
BACKGROUND: Understanding the relationship between dose, lung exposure, and drug efficacy continues to be a challenging aspect of inhaled drug development. An experimental inhalation platform was developed using mometasone furoate to link rodent lung exposure to its in vivo pharmacodynamic (PD) effects. METHODS: We assessed the effect of mometasone delivered directly to the lung in two different rodent PD models of lung inflammation. The data obtained were used to develop and evaluate a mathematical model to estimate drug dissolution, transport, distribution, and efficacy, following inhaled delivery in rodents and humans. RESULTS: Mometasone directly delivered to the lung, in both LPS and Alternaria alternata rat models, resulted in dose dependent inhibition of BALf cellular inflammation. The parameters for our mathematical model were calibrated to describe the observed lung and systemic exposure profiles of mometasone in humans and in animal models. We found that physicochemical properties, such as lung fluid solubility and lipophilicity, strongly influenced compound distribution and lung retention. CONCLUSIONS: Presently, we report on a novel and sophisticated mathematical model leading to improvements in a current inhaled drug development practices by providing a quantitative understanding of the relationship between PD effects and drug concentration in lungs.
Assuntos
Alternariose/tratamento farmacológico , Anti-Inflamatórios/administração & dosagem , Cálculos da Dosagem de Medicamento , Pneumopatias Fúngicas/tratamento farmacológico , Pulmão/efeitos dos fármacos , Modelos Biológicos , Furoato de Mometasona/administração & dosagem , Pneumonia/tratamento farmacológico , Administração por Inalação , Aerossóis , Alternaria , Alternariose/metabolismo , Alternariose/microbiologia , Alternariose/fisiopatologia , Animais , Anti-Inflamatórios/farmacocinética , Modelos Animais de Doenças , Humanos , Lipopolissacarídeos , Pulmão/metabolismo , Pulmão/fisiopatologia , Pneumopatias Fúngicas/metabolismo , Pneumopatias Fúngicas/microbiologia , Pneumopatias Fúngicas/fisiopatologia , Masculino , Furoato de Mometasona/farmacocinética , Pneumonia/induzido quimicamente , Pneumonia/metabolismo , Pneumonia/fisiopatologia , Ratos Endogâmicos BN , Ratos Sprague-Dawley , Especificidade da Espécie , Distribuição TecidualRESUMO
BACKGROUND: The impact of anti-TNF, corticosteroid and analgesic therapy on inflammation and pain was evaluated in a novel mono-arthritic multi-flare rat Streptococcal Cell Wall (SCW) model using Etanercept, Dexamethasone and Buprenorphine. METHODS: Multiple flares of arthritis were induced with an intra-articular injection of SCW in the hind ankle on day 1, followed by intravenous challenges on days 21 and 42. Inflammation and pain were monitored in the hind paws. Cytokine profiling, cell phenotyping, bioluminescence imaging and histopathological evaluation were also performed. RESULTS: Local injection of SCW caused a rapid onset of inflammation and pain in the injected ankle which resolved within 4 days (Flare 1). Intravenous injection 20 days after sensitization resulted in an increase in ankle diameter and pain, which partially resolved in 8 days (Flare 2). The subsequent intra-venous injection in the same animals 14 days after resulted in a more chronic disease with inflammation and pain persisting over a period of 10 days (Flare 3). In Flare 2, therapeutic administration of Dexamethasone inhibited paw swelling (95%; P<0.001) and pain (55%; P<0.05). Therapeutic administration of Buprenorphine inhibited pain (80%; P<0.001) without affecting paw swelling (0%). Prophylactic administration of Etanercept in Flare 2 inhibited paw swelling (≥60%; P<0.001) and pain by ≥30%. Expression of IL-1ß, IL-6, MCP-1 and CINC was reduced by >50% (P<0.001). Treatment with Etanercept in Flare 3 inhibited paw swelling by 60% (P<0.001) and pain by 25%. Prior treatment with Etanercept in Flare 2 followed by re-administration in Flare 3 led to a complete loss in the efficacy of Etanercept. Systemic exposure of Etanercept corroborated with lack of efficacy. Dexamethasone inhibited inflammation and pain in both Flares 2 and 3 (P<0.001). CONCLUSIONS: We established a novel multi-flare SCW arthritis model enabling drug intervention in different stages of disease. We show for the first time the evaluation of inflammation and pain simultaneously in this model. Etanercept and Dexamethasone inhibited inflammation, pain and proinflammatory cytokines in this model. Taken together, this model facilitates the assessment of anti-rheumatic agents targeting inflammation and pain in the multiple flare paradigm and offers a powerful tool for drug discovery.
Assuntos
Antirreumáticos/uso terapêutico , Artrite Experimental/tratamento farmacológico , Parede Celular , Imunoglobulina G/uso terapêutico , Dor/tratamento farmacológico , Receptores do Fator de Necrose Tumoral/uso terapêutico , Streptococcus , Animais , Artrite Experimental/induzido quimicamente , Artrite Experimental/patologia , Etanercepte , Feminino , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Inflamação/patologia , Dor/induzido quimicamente , Dor/patologia , Ratos , Ratos Endogâmicos LewRESUMO
Alternaria alternata is a fungal allergen linked to the development of severe asthma in humans. In view of the clinical relationship between A. alternata and asthma, we sought to investigate the allergic activity of this antigen after direct application to the lungs of Brown Norway rats. Here we demonstrate that a single intratracheal instillation of A. alternata induces dose and time dependent eosinophil influx, edema and Type 2 helper cell cytokine production in the lungs of BN rats. We established the temporal profile of eosinophilic infiltration and cytokine production, such as Interleukin-5 and Interleukin-13, following A. alternata challenge. These responses were comparable to Ovalbumin induced models of asthma and resulted in peak inflammatory responses 48h following a single challenge, eliminating the need for multiple sensitizations and challenges. The initial perivascular and peribronchiolar inflammation preceded alveolar inflammation, progressing to a more sub-acute inflammatory response with notable epithelial cell hypertrophy. To limit the effects of an A. alternata inflammatory response, MK-7246 was utilized as it is an antagonist for Chemoattractant Receptor-homologous molecule expressed in Th2 cells. In a dose-dependent manner, MK-7246 decreased eosinophil influx and Th2 cytokine production following the A. alternata challenge. Furthermore, therapeutic administration of corticosteroids resulted in a dose-dependent decrease in eosinophil influx and Th2 cytokine production. Reproducible asthma-related outcomes and amenability to pharmacological intervention by mechanisms relevant to asthma demonstrate that an A. alternata induced pulmonary inflammation in BN rats is a valuable preclinical pharmacodynamic in vivo model for evaluating the pharmacological inhibitors of allergic pulmonary inflammation.
Assuntos
Alternaria/efeitos dos fármacos , Anti-Inflamatórios/farmacologia , Carbolinas/farmacologia , Pneumonia/tratamento farmacológico , Receptores de Formil Peptídeo/metabolismo , Células Th2/efeitos dos fármacos , Alérgenos/imunologia , Alternaria/imunologia , Animais , Asma/tratamento farmacológico , Asma/imunologia , Asma/metabolismo , Citocinas/imunologia , Citocinas/metabolismo , Eosinófilos/efeitos dos fármacos , Eosinófilos/imunologia , Eosinófilos/metabolismo , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Interleucina-13/imunologia , Interleucina-13/metabolismo , Interleucina-5/imunologia , Interleucina-5/metabolismo , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Pulmão/metabolismo , Masculino , Ovalbumina/imunologia , Ovalbumina/farmacologia , Pneumonia/imunologia , Pneumonia/metabolismo , Ratos , Ratos Endogâmicos BN , Receptores de Formil Peptídeo/imunologia , Células Th2/imunologiaRESUMO
Injury to lung epithelial cells has a role in multiple lung diseases. We previously identified mitsugumin 53 (MG53) as a component of the cell membrane repair machinery in striated muscle cells. Here we show that MG53 also has a physiological role in the lung and may be used as a treatment in animal models of acute lung injury. Mice lacking MG53 show increased susceptibility to ischaemia-reperfusion and overventilation-induced injury to the lung when compared with wild-type mice. Extracellular application of recombinant human MG53 (rhMG53) protein protects cultured lung epithelial cells against anoxia/reoxygenation-induced injuries. Intravenous delivery or inhalation of rhMG53 reduces symptoms in rodent models of acute lung injury and emphysema. Repetitive administration of rhMG53 improves pulmonary structure associated with chronic lung injury in mice. Our data indicate a physiological function for MG53 in the lung and suggest that targeting membrane repair may be an effective means for treatment or prevention of lung diseases.
Assuntos
Lesão Pulmonar Aguda/tratamento farmacológico , Lesão Pulmonar Aguda/patologia , Proteínas de Transporte/metabolismo , Proteínas de Transporte/farmacologia , Membrana Celular/efeitos dos fármacos , Terapia de Alvo Molecular/métodos , Lesão Pulmonar Aguda/genética , Animais , Proteínas de Transporte/administração & dosagem , Proteínas de Transporte/genética , Hipóxia Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Células Cultivadas , Modelos Animais de Doenças , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/patologia , Feminino , Humanos , Pulmão/patologia , Masculino , Proteínas de Membrana , Camundongos Knockout , Ratos , Ratos Sprague-Dawley , Ratos Wistar , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/farmacologia , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/patologia , Respiração Artificial/efeitos adversos , Proteínas com Motivo TripartidoRESUMO
Nasal congestion is one of the most troublesome symptoms of many upper airways diseases. We characterized the effect of selective α2c-adrenergic agonists in animal models of nasal congestion. In porcine mucosa tissue, compound A and compound B contracted nasal veins with only modest effects on arteries. In in vivo experiments, we examined the nasal decongestant dose-response characteristics, pharmacokinetic/pharmacodynamic relationship, duration of action, potential development of tolerance, and topical efficacy of α2c-adrenergic agonists. Acoustic rhinometry was used to determine nasal cavity dimensions following intranasal compound 48/80 (1%, 75 µl). In feline experiments, compound 48/80 decreased nasal cavity volume and minimum cross-sectional areas by 77% and 40%, respectively. Oral administration of compound A (0.1-3.0 mg/kg), compound B (0.3-5.0 mg/kg), and d-pseudoephedrine (0.3 and 1.0 mg/kg) produced dose-dependent decongestion. Unlike d-pseudoephedrine, compounds A and B did not alter systolic blood pressure. The plasma exposure of compound A to produce a robust decongestion (EC(80)) was 500 nM, which related well to the duration of action of approximately 4.0 hours. No tolerance to the decongestant effect of compound A (1.0 mg/kg p.o.) was observed. To study the topical efficacies of compounds A and B, the drugs were given topically 30 minutes after compound 48/80 (a therapeutic paradigm) where both agents reversed nasal congestion. Finally, nasal-decongestive activity was confirmed in the dog. We demonstrate that α2c-adrenergic agonists behave as nasal decongestants without cardiovascular actions in animal models of upper airway congestion.
Assuntos
Agonistas de Receptores Adrenérgicos alfa 2/farmacologia , Descongestionantes Nasais/farmacologia , Receptores Adrenérgicos alfa 2/metabolismo , Rinite Vasomotora/tratamento farmacológico , Administração Intranasal , Administração Oral , Agonistas de Receptores Adrenérgicos alfa 2/administração & dosagem , Agonistas de Receptores Adrenérgicos alfa 2/farmacocinética , Agonistas de Receptores Adrenérgicos alfa 2/uso terapêutico , Antagonistas de Receptores Adrenérgicos alfa 2/farmacologia , Animais , Gatos , Modelos Animais de Doenças , Cães , Relação Dose-Resposta a Droga , Técnicas In Vitro , Masculino , Descongestionantes Nasais/administração & dosagem , Descongestionantes Nasais/farmacocinética , Descongestionantes Nasais/uso terapêutico , Mucosa Nasal/irrigação sanguínea , Mucosa Nasal/efeitos dos fármacos , Mucosa Nasal/metabolismo , Rinite Vasomotora/metabolismo , Suínos , Vasoconstrição/efeitos dos fármacosRESUMO
Accumulating evidence indicates protective actions of mineralocorticoid antagonists (MR antagonists) on cardiovascular pathology, which includes blunting vascular inflammation and myocardial fibrosis. We examined the anti-inflammatory and anti-fibrotic potential of MR antagonists in rodent respiratory models. In an ovalbumin allergic and challenged Brown Norway rat model, the total cell count in nasal lavage was 29,348 ± 5451, which was blocked by spironolactone (0.3-60 mg/kg, p.o.) and eplerenone (0.3-30 mg/kg, p.o.). We also found that MR antagonists attenuated pulmonary inflammation in the Brown Norway rat. A series of experiments were conducted to determine the actions of MR blockade in acute/chronic lung injury models. (1) Ex vivo lung slice rat experiments found that eplerenone (0.01 and 10 µM) and spironolactone (10 µM) diminished lung hydroxyproline concentrations by 55 ± 5, 122 ± 9, and 83 ± 8%. (2) In in vivo studies, MR antagonists attenuated the increases in bronchioalveolar lavage (BAL) neutrophils and macrophages caused by lung bleomycin exposure. In separate studies, bleomycin (4.0 U/kg, i.t.) increased lung levels of hydroxyproline by approximately 155%, which was blocked by spironolactone (10-60 mg/kg, p.o.). In a rat Lipopolysaccharide (LPS) model, spironolactone inhibited acute increases in BAL cytokines with moderate effects on neutrophils. Finally, we found that chronic LPS exposure significantly increased end expiratory lung and decreased lung elastance in the mouse. These functional effects of chronic LPS were improved by MR antagonists. Our results demonstrate that MR antagonists have significant pharmacological actions in the respiratory system.
Assuntos
Bleomicina/efeitos adversos , Antagonistas de Receptores de Mineralocorticoides/farmacologia , Pneumonia/tratamento farmacológico , Receptores de Mineralocorticoides/metabolismo , Animais , Modelos Animais de Doenças , Elasticidade/efeitos dos fármacos , Fibrose , Hidroxiprolina/metabolismo , Hipersensibilidade/tratamento farmacológico , Hipersensibilidade/metabolismo , Hipersensibilidade/patologia , Hipersensibilidade/fisiopatologia , Lipopolissacarídeos/efeitos adversos , Pulmão/efeitos dos fármacos , Pulmão/patologia , Pulmão/fisiopatologia , Masculino , Camundongos , Antagonistas de Receptores de Mineralocorticoides/uso terapêutico , Pneumonia/metabolismo , Pneumonia/patologia , Pneumonia/fisiopatologia , Ventilação Pulmonar/efeitos dos fármacos , RatosRESUMO
Cough continues to be one of the top reasons why patients seek medical attention from health care providers. The prescription antitussive market is dominated by opioids, such as codeine that produces inconsistent efficacy and is often accompanied by significant side effect liabilities. Consequently, cough represents an unmet medical need and an underserved market. Yet, against the backdrop of increasing cough research, the development of novel treatments has been exceptionally challenging with dextromethorphan being the last US drug approved for cough almost a half century ago. We support the position that an unambiguous and actionable 'road map' that clearly delineates the pathway forward for new cough suppressants from basic research to and beyond clinical proof-of-concept studies will be an important aspect for future success of this pharmacological class of drug. Pivotal to the establishment of such a road map will be the review of lessons learned from antitussive agents that have been recently progressed to proof-of-concept trials. In the present commentary, we briefly discuss observations and challenges pertaining to SCH 486757, a selective orally active NOP agonist that has recently advanced to human antitussive testing.
Assuntos
Antitussígenos/farmacologia , Compostos Azabicíclicos/farmacologia , Tosse/tratamento farmacológico , Pirimidinas/farmacologia , Animais , Antitussígenos/administração & dosagem , Antitussígenos/uso terapêutico , Compostos Azabicíclicos/administração & dosagem , Compostos Azabicíclicos/uso terapêutico , Ensaios Clínicos como Assunto , Codeína/administração & dosagem , Codeína/farmacologia , Dextrometorfano/administração & dosagem , Dextrometorfano/farmacologia , Modelos Animais de Doenças , Cães , Avaliação Pré-Clínica de Medicamentos , Cobaias , Humanos , Peptídeos Opioides/agonistas , Peptídeos Opioides/metabolismo , Pirimidinas/administração & dosagem , Pirimidinas/uso terapêutico , Ratos , Receptores Opioides/agonistas , NociceptinaRESUMO
We define the pharmacological and pharmacokinetic profiles of a novel α(2C)-adrenoceptor agonist, compound A [N-[3,4-dihydro-4-(1H-imidazol-4-ylmethyl)-2H-1,4-benzoxazin-6-yl]-N-ethyl-N'-methylurea]. This compound has high affinity (K(i)) for the human α(2C)-adrenoceptor (K(i) = 12 nM), and 190- to 260-fold selectivity over the α(2A)- and α(2B)-adrenoceptor subtypes. In cell-based functional assays, compound A produced good agonist (EC(50) = 166 nM) and efficacy (E(max) = 64%) responses at the α(2C)-adrenoceptor, much lower potency and efficacy at the α(2A)-adrenoceptor (EC(50) = 1525 nM; E(max) = 8%) and α(2B)-adrenoceptor (EC(50) = 5814 nM; E(max) = 21%) subtypes, and low or no affinity and functional activity at the α(1A)-, α(1B)-, and α(1D)-adrenoceptor subtypes. In the human saphenous vein postjunctional α(2C)-adrenoceptor bioassay, compound A functions as a potent agonist (pD(2) = 6.3). In a real-time contraction bioassay of pig nasal mucosa, compound A preferentially constricted the veins (EC(50) = 108 nM), and the magnitude of arteriolar contraction reached only 50% of the maximum venular responses. Compound A exhibited no effect on locomotor activity, sedation, and body temperature in mice (up to 100 mg/kg) and did not cause hypertension and mydriasis (30 mg/kg) in conscious rats. Compound A is orally bioavailable (24%) with good plasma exposure. This compound is a substrate for the efflux P-glycoprotein transporter, resulting in very low central nervous system (CNS) penetration. In summary, compound A is a highly selective, orally active, and non-CNS-penetrating α(2C)-adrenoceptor agonist with desirable in vitro and in vivo pharmacological properties suitable for the treatment of nasal congestion.
Assuntos
Agonistas Adrenérgicos/química , Agonistas Adrenérgicos/farmacologia , Compostos de Metilureia/química , Compostos de Metilureia/farmacologia , Morfolinas/química , Morfolinas/farmacologia , Atividade Motora/efeitos dos fármacos , Mucosa Nasal/efeitos dos fármacos , Receptores Adrenérgicos alfa 2/metabolismo , Veia Safena/efeitos dos fármacos , Agonistas Adrenérgicos/metabolismo , Animais , Células CHO , Cricetinae , Cricetulus , Humanos , Masculino , Compostos de Metilureia/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Morfolinas/metabolismo , Atividade Motora/fisiologia , Mucosa Nasal/metabolismo , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes/agonistas , Proteínas Recombinantes/metabolismo , Veia Safena/metabolismo , SuínosRESUMO
The objectives of these studies were to characterize the pharmacokinetics (PK) of the nasal decongestant pseudoephedrine (PSE) in rats, dogs, and monkeys, and to evaluate its lower gastrointestinal tract regional bioavailability in rats. An LC-MS/MS assay with a lower limit of quantification (LLOQ) of 0.4 ng/mL of plasma was developed for the analysis of PSE in animal plasma. The total body clearance (CL) was the highest in rats (78 mL/min/kg), lowest in monkeys (15 mL/min/kg) and the dog averaged in between (33 mL/min/kg). The volume of distribution at steady state (Vdss) ranged from 3-5 L/kg in all species. In rats and dogs, the mean half-lives (t1/2) was ≈1.5 hr, while in monkeys the mean t1/2 was 4.6 hr, comparable to that observed in adult humans (4-8 hr). The oral bioavailability was 38, 58 and 78% in rats, dogs and monkeys. The bioavailability following intra-ileum or intra-colonic administration in rats was superior to that following oral dosing (66% and 78%, respectively) suggesting that colonic absorption may be compensating for the short half-life, thus enabling successful QD sustained release formulations of PSE. The pharmacokinetic/pharmacodynamic relationship (PK/PD) of PSE was also investigated in a feline model of nasal congestion to establish efficacious trough concentrations in cats for a comparison with that in humans. The PK/PD in the cat model followed a sigmoid Emax model with an EC50 (plasma concentration that elicits 50% of the maximum response) of 0.32 ±0.05 (SD) µM consistent with human plasma concentrations required for efficacy.
Assuntos
Descongestionantes Nasais/farmacocinética , Descongestionantes Nasais/uso terapêutico , Obstrução Nasal/tratamento farmacológico , Pseudoefedrina/farmacocinética , Pseudoefedrina/uso terapêutico , Animais , Área Sob a Curva , Disponibilidade Biológica , Gatos , Cães , Feminino , Meia-Vida , Humanos , Macaca fascicularis , Masculino , Ratos , Ratos Sprague-Dawley , Especificidade da EspécieRESUMO
BACKGROUND: Histamine and cysteinyl leukotrienes are pivotal mast cell mediators which contribute considerably and likely complementary to the symptoms of allergic rhinitis. Currently, we sought to explore the direct actions of histamine and leukotriene D(4) (LTD(4)), a cysteinyl leukotriene, on porcine nasal arteries and veins. We also studied combined blocks of histamine and cysteinyl leukotrienes using loratadine and montelukast in an in vivo model of allergy-mediated nasal inflammation. METHODS: For the evaluation of the action of histamine and LTD(4) on arteries and veins, porcine nasal mucosa was isolated and cut into slices (100-300 microm thick). Real-time images of the nasal arteries and veins were recorded and vessel activities estimated by changes in cross-sectional area before and after the tested drugs. For the in vivo studies, the effect of loratadine and montelukast given alone and in combination was examined on upper airway inflammation in ovalbumin-sensitized and -challenged Brown Norway rats. RESULTS: Both histamine (0.001-10 micromol/l) and LTD(4) (0.001-10 micromol/l) produced a concentration-dependent increase in the lumen area of nasal mucosa arteries and veins. Histamine (0.01 micromol/l) alone produced a 24 and 12% increase in cross-sectional areas of arteries and veins, respectively. LTD(4) (0.001 micromol/l) alone increased artery and vein dilation by about 17 and 9%, respectively. Combination treatment with histamine (0.01 micromol/l) and LTD(4) (0.001 micromol/l) increased vessel dilation by 65% (arteries) and 26% (veins). In our in vivo Brown Norway rat studies, oral loratadine (0.01-10 mg/kg) and montelukast (0.01-10 mg/kg) significantly reduced antigen-induced total nasal inflammatory cell infiltration in a dose-dependent manner. The antiinflammatory dose-response curve of loratadine was shifted to the left when studied in combination with montelukast (0.01 mg/kg). Similarly, the dose-response characteristics of montelukast (0.01-10 mg/kg) was shifted in the presence of loratadine (0.01 mg/kg). CONCLUSION: Our studies support the position that histamine and cysteinyl leukotrienes may act collaboratively to elicit allergic nasal pathologies such as upper airway inflammation and nasal vessel dilation (which may translate into increased nasal mucosal engorgement). Furthermore, the current results are supportive of the hypothesis that combined treatment of allergic rhinitis with an H(1) receptor antagonist and a CysLT(1) receptor antagonist may have greater benefit than sole treatment with these agents alone.
Assuntos
Cisteína/fisiologia , Histamina/fisiologia , Leucotrienos/fisiologia , Mucosa Nasal/irrigação sanguínea , Mucosa Nasal/efeitos dos fármacos , Rinite/tratamento farmacológico , Acetatos/farmacologia , Acetatos/uso terapêutico , Animais , Ciclopropanos , Cisteína/antagonistas & inibidores , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Quimioterapia Combinada , Feminino , Antagonistas não Sedativos dos Receptores H1 da Histamina/farmacologia , Antagonistas não Sedativos dos Receptores H1 da Histamina/uso terapêutico , Hipersensibilidade/tratamento farmacológico , Técnicas In Vitro , Antagonistas de Leucotrienos/farmacologia , Antagonistas de Leucotrienos/uso terapêutico , Leucotrieno D4/antagonistas & inibidores , Leucotrieno D4/fisiologia , Loratadina/farmacologia , Loratadina/uso terapêutico , Masculino , Mucosa Nasal/patologia , Infiltração de Neutrófilos/efeitos dos fármacos , Quinolinas/farmacologia , Quinolinas/uso terapêutico , Ratos , Ratos Endogâmicos BN , Rinite/imunologia , Sulfetos , Sus scrofaRESUMO
BACKGROUND: Nasal congestion is the most troublesome symptom associated with a variety of upper airway diseases, including allergic rhinitis and the common cold. A better understanding of the mechanisms that regulate nasal cavity caliber may engender the development of novel treatment strategies. It is well accepted that alpha-adrenergic (both alpha(1) and alpha(2)) mechanisms play a fundamental role in the control and maintenance of basal nasal patency. JP-1302 is a selective alpha(2c)-subtype antagonist that has been recently described in the scientific literature. Thus, we sought to examine the potential effects of this new pharmacological tool on basal nasal patency. METHODS: Using acoustic rhinometry, we studied the activity of the selective alpha(2c)-antagonist JP-1302 on nasal cavity volumes in an anesthetized cat. Cumulative concentrations of JP-1302 were applied directly into the right nasal cavity. Changes in the nasal cavity geometry of the drug-treated naris relative to the untreated left nasal cavity were determined. In separate studies, the nonselective alpha(2)-antagonist yohimbine and the nonselective alpha(1)-antagonist prazosin were run as comparators. Systolic blood pressure was measured at the hind leg, using an ultrasonic Doppler flow detector. RESULTS: JP-1302 (0.03, 0.1, 0.3 and 1.0%) administered by the intranasal route decreased nasal cavity volumes from baseline values by 17, 25, 40 and 40%, respectively. Yohimbine (0.03, 0.1, 0.3 and 1.0%) decreased volumes by 19, 36, 46 and 53%, and topical administration of the nonselective alpha(1)-antagonist prazosin (0.001, 0.003, 0.01, 0.03 and 0.1%) decreased volumes by 6, 47, 56, 64 and 71%, respectively. JP-1302, yohimbine and prazosin, at the dose level tested, did not alter the blood pressure. CONCLUSIONS: The present set of experiments indicates that both alpha(1)- and alpha(2)-adrenergic receptors are involved in the maintenance of basal nasal patency in the cat. Moreover, alpha(2c)-receptors may play a significant role in the sympathetic control of upper airway function.
Assuntos
Cavidade Nasal/fisiologia , Neurônios/fisiologia , Receptores Adrenérgicos alfa 2/fisiologia , Sistema Nervoso Simpático/fisiologia , Acridinas/administração & dosagem , Acridinas/efeitos adversos , Acridinas/farmacologia , Administração Intranasal , Antagonistas de Receptores Adrenérgicos alfa 1 , Antagonistas de Receptores Adrenérgicos alfa 2 , Antagonistas Adrenérgicos alfa/administração & dosagem , Antagonistas Adrenérgicos alfa/efeitos adversos , Antagonistas Adrenérgicos alfa/farmacologia , Anestesia , Animais , Pressão Sanguínea/efeitos dos fármacos , Gatos , Relação Dose-Resposta a Droga , Masculino , Cavidade Nasal/anatomia & histologia , Cavidade Nasal/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Piperazinas/administração & dosagem , Piperazinas/efeitos adversos , Piperazinas/farmacologia , Isoformas de Proteínas/antagonistas & inibidores , Isoformas de Proteínas/fisiologia , Rinite/tratamento farmacológico , Rinometria Acústica , Sistema Nervoso Simpático/efeitos dos fármacosRESUMO
We describe the pharmacological and pharmacokinetic profiles of SCH 486757, a nociceptin/orphanin FQ peptide (NOP) receptor agonist that has recently entered human clinical trials for cough. SCH 486757 selectively binds human NOP receptor (K(i)=4.6+/-0.61nM) over classical opioid receptors. In a guinea pig capsaicin cough model, SCH 486757 (0.01-1mg/kg) suppressed cough at 2, 4, and 6h post oral administration with a maximum efficacy occurring at 4h equivalent to codeine, hydrocodone, dextromethorphan and baclofen. The antitussive effects of SCH 486757 (3.0mg/kg, p.o.) was blocked by the NOP receptor antagonist J113397 (12mg/kg, i.p.) but not by naltrexone (10mg/kg, p.o.). SCH 486757 does not produce tolerance to its antitussive activity after a 5-day BID dosing regimen. After acute and chronic dosing paradigms, SCH 486757 (1mg/kg) inhibited capsaicin-evoked coughing by 46+/-9% and 40+/-11%, respectively. In a feline mechanically-evoked cough model, SCH 486757 produces a maximum inhibition of cough and expiratory abdominal electromyogram amplitude of 59 and 61%, respectively. SCH 486757 did not significantly affect inspiratory electromyogram amplitude. We examined the abuse potential of SCH 486757 (10mg/kg, p.o.) in a rat conditioned place preference procedure which is sensitive to classical drugs of abuse, such as amphetamine and morphine. SCH 486757 was without effect in this model. Finally, SCH 486757 displays a good oral pharmacokinetic profile in the guinea pig, rat and dog. We conclude that SCH 486757 has a favorable antitussive profile in preclinical animal models.
Assuntos
Antitussígenos/uso terapêutico , Tosse/tratamento farmacológico , Receptores Opioides/agonistas , Animais , Compostos Azabicíclicos/farmacologia , Gatos , Cães , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Cobaias , Masculino , Pirimidinas/farmacologia , Ratos , Ratos Sprague-Dawley , Receptores Opioides/metabolismo , Receptor de NociceptinaRESUMO
Currently, opiates are widely used as antitussives but have substantial side effects. Recently, it has been proposed that NOP1 receptor agonists may be useful as a novel approach to cough suppression. Therefore, we compared the effect of NOP1 receptor agonist SCH486757 with matched placebo and codeine in a multicentre, double-blind, parallel-group study in patients with subacute cough. The primary outcome was change in cough severity scores, with the key secondary outcome change in objective daytime cough counts. We studied 91 subjects with subacute cough [59 (65%) female, median age = 41(range = 18-64) years, and median cough duration = 33 (range = 16-99) days]. Subjects were randomised to receive either SCH486757 100 mg, codeine 30 mg, or matched placebo twice daily for 5 days. Cough severity was scored throughout using a diary card and objective cough frequency recorded for 8 h at baseline and on the first and last treatment days. There were no significant differences in changes in average cough severity scores from baseline to treatment between SCH486757 and placebo [mean change = -0.57 (-30.1%) vs. mean change = -0.49 (-19.7%); P = 0.56] or between codeine and placebo [mean change = -0.72 (-33.2%); P = 0.07 compared to placebo). Changes in objective cough counts also showed no differences between the three treatment groups. There were some hints of possible limited antitussive efficacy with SCH486757. Unfortunately, the maximum clinical dose is limited by its tendency to produce somnolence. If the therapeutic ratio of NOP1 agonists could be improved, these drugs may still prove to contain effective antitussives.
Assuntos
Antitussígenos/uso terapêutico , Compostos Azabicíclicos/uso terapêutico , Tosse/tratamento farmacológico , Pirimidinas/uso terapêutico , Doença Aguda , Adulto , Análise de Variância , Método Duplo-Cego , Feminino , Humanos , Análise de Intenção de Tratamento , Masculino , Pessoa de Meia-Idade , Peptídeos Opioides , Receptores Opioides , Índice de Gravidade de Doença , Adulto Jovem , Receptor de NociceptinaRESUMO
BACKGROUND: Histamine and leukotrienes act to exert numerous local and systemic effects that contribute to the pathophysiology of allergic rhinitis. The aim of these experiments was to evaluate the nasal decongestant effects of loratadine and montelukast alone and in combination in a feline model of nasal congestion. We also studied the decongestant actions of the alpha-agonist adrenergic agonist D-pseudoephedrine with and without desloratadine. METHODS: Acoustic rhinometry was used to determine nasal cavity dimensions after intranasal compound 48/80. Cats were given D-pseudoephedrine (0.3 mg/kg) alone or in combination with desloratadine (5 mg/kg) 1 hour before nasal provocation with compound 48/80 (1%, 75 microliters) to either the left or right nasal passageway. Using a similar design, the nasal decongestant effects of montelukast (1 mg/kg) and loratadine (10 mg/kg) were studied alone and in combination. RESULTS: The addition of desloratadine to D-pseudoephedrine did not improve decongestant efficacy compared with each drug given individually. In contrast, when montelukast (1 mg/kg) was given in combination with loratadine (10 mg/kg), the decongestant activity was greater than when these drugs were administered separately. Sixty minutes after compound 48/80 provocation the nasal cavity volume ratio (volume ratio of the compound 48/80 treated/untreated nasal passageway) for the control, montelukast alone, loratadine alone, and the montelukast plus loratadine-treated groups were 0.20 +/- 0.03, 0.24 +/- 0.01, 0.28 +/- 0.03, and 0.50 +/- 0.03. CONCLUSION: Concomitant montelukast plus loratadine produces a greater degree of nasal decongestion compared with montelukast or loratadine alone in an experimental model of nasal congestion.
Assuntos
Acetatos/administração & dosagem , Antagonistas não Sedativos dos Receptores H1 da Histamina/administração & dosagem , Antagonistas de Leucotrienos/administração & dosagem , Loratadina/administração & dosagem , Obstrução Nasal/tratamento farmacológico , Quinolinas/administração & dosagem , Animais , Gatos , Ciclopropanos , Modelos Animais de Doenças , Quimioterapia Combinada , Humanos , Loratadina/análogos & derivados , Masculino , Cavidade Nasal/anatomia & histologia , Cavidade Nasal/efeitos dos fármacos , Obstrução Nasal/fisiopatologia , Testes de Provocação Nasal , Pseudoefedrina/administração & dosagem , Rinometria Acústica , Sulfetos , Resultado do TratamentoRESUMO
BACKGROUND: Previous studies have demonstrated that nociceptin/orphanin FQ (N/OFQ), the endogenous peptide ligand for the G-protein-coupled NOP receptor, inhibits cough in experimental models. SCH 225288 is a nonpeptide, orally active NOP agonist that may provide the foundation for the development of novel treatments for cough. METHODS: First we characterized the selectivity of SCH 225288 in human receptor binding assays. Afterwards, the antitussive activity of SCH 225288 was studied in three mechanistically distinct cough models. Specifically, we observed the cough-suppressant effect of SCH 225288 in a guinea pig capsaicin irritant-evoked cough model, a feline mechanically induced cough model and finally in a canine Bordetella bronchiseptica disease model. RESULTS: SCH 225288 selectively binds human NOP receptor (K(i) = 0.38 +/- 0.02 nmol/l) over classical opioid receptors (COR). In a guinea pig capsaicin cough model, SCH 225288 (0.1-1 mg/kg) suppressed cough at 2, 4, and 6 h after oral administration. The antitussive effect of SCH 225288 (3.0 mg/kg, p.o.) was blocked by the NOP antagonist J113397 (12 mg/kg, i.p.) but not by the classical opioid receptor (COR) antagonist, naltrexone (3.0 mg/kg, i.p.). In the anesthetized cat, we evaluated the effects of SCH 225288 given either intravenously or via the intravertebral artery against the increases in cough number and respiratory expiratory and inspiratory muscle (rectus abdominis and parasternal) electromyographic (EMG) activities due to perturbations of the intrathoracic trachea. SCH 225288 (0.03-3.0 mg/kg, i.v.) inhibited both cough number and abdominal EMG amplitudes. Similarly, SCH 225288 (0.001-0.3 mg/kg) administered intra-arterially also diminished cough number and abdominal EMG amplitudes. No significant effect of the drug was noted on parasternal EMG activity. Finally, we studied the antitussive actions of SCH 225288 (1.0 mg/kg) in a canine B. bronchiseptica disease model. In this model, dogs were challenged intranasally with B. bronchiseptica. Comparisons were made between a vehicle group, an SCH 225288 (1.0 mg/kg, p.o., q.d.) and a butorphanol (0.6 mg/kg, p.o., b.i.d.) group on the mean change in cough scores from baseline values and days 6-9 after B. bronchiseptica challenge. SCH 225288 (1.0 mg/kg, p.o., q.d.) displayed a positive antitussive tendency (p = 0.06) to inhibit B. bronchiseptica cough whereas butorphanol (0.6 mg/kg, p.o., b.i.d.) was devoid of antitussive activity. CONCLUSIONS: Taken together, the present data show that SCH 225288 is a potent and effective antitussive agent in animal models of cough. Furthermore, these findings indicate that NOP agonists represent a promising new therapeutic approach for the treatment of cough without the side effect liabilities associated with opioid antitussives.
Assuntos
Antitussígenos/farmacologia , Tosse/tratamento farmacológico , Receptores Opioides/agonistas , Tropanos/farmacologia , Animais , Antitussígenos/administração & dosagem , Antitussígenos/efeitos adversos , Infecções por Bordetella/tratamento farmacológico , Infecções por Bordetella/veterinária , Bordetella bronchiseptica/isolamento & purificação , Células CHO , Capsaicina , Gatos , Cricetinae , Cricetulus , Modelos Animais de Doenças , Cães , Relação Dose-Resposta a Droga , Feminino , Cobaias , Humanos , Masculino , Especificidade da Espécie , Fatores de Tempo , Tropanos/administração & dosagem , Tropanos/efeitos adversos , Receptor de NociceptinaRESUMO
A series of 3-pyridinyl-tropane analogues based on previously reported compound 1 have been synthesized and shown to bind to the nociceptin receptor with high affinity. From the SAR study and our lead optimization efforts, compound 10 was found to possess potent oral antitussive activity in the capsaicin-induced guinea pig model. The rationale for compound selection and the biological profile of the optimized lead (10) are disclosed.