RESUMO
The natural product hinokitiol mobilizes iron across lipid bilayers at low concentrations and restores hemoglobinization in iron transporter protein-deficient systems. But hinokitiol fails to similarly mobilize iron at higher concentrations, limiting its uses in chemical biology and medicine. Here we show that at higher concentrations, hinokitiol3:Fe(III) complexes form large, higher-order aggregates, leading to loss of transmembrane iron mobilization. Guided by this understanding and systematic structure-function studies enabled by modular synthesis, we identified FeM-1269, which minimally aggregates and dose-dependently mobilizes iron across lipid bilayers even at very high concentrations. In contrast to hinokitiol, FeM-1269 is also well-tolerated in animals at high doses for extended periods of time. In a mouse model of anemia of inflammation, FeM-1269 increases serum iron, transferrin saturation, hemoglobin and hematocrit. This rationally developed iron-mobilizing small molecule has enhanced potential as a molecular prosthetic for understanding and potentially treating iron transporter deficiencies.
RESUMO
Cutaneous and superficial fungal infections affecting the skin, nails, and hair of humans are caused primarily by dermatophytes of the genera Trichophyton and Epidermophyton or by yeasts of the genera Candida and Malassezia. Onychomycosis is a common fungal infection of the nail that frequently coexists with tinea pedis, the most prevalent mycotic skin infection. Efficacy rates for current topical onychomycosis therapies are hampered by low drug penetration across the nail plate, which is theoretically obviated with nitric oxide (NO)-based topical therapies. The Nitricil technology platform is comprised of polysiloxane-based macromolecules that stably release therapeutic levels of NO. In the reported studies, NVN1000, the lead candidate of the platform, was assessed for its spectrum of in vitro activity against a broad range of filamentous fungi and yeast species commonly associated with cutaneous fungal infections. Time-kill assays demonstrated that NVN1000 exhibited fungicidal activity as early as 4 h. Additionally, the penetration of several unique NVN1000 NO-releasing drug product formulations (gel, cream, and lacquer) was evaluated following a single topical application in an in vitro infected human nail assay, with all formulations showing similar inhibition of fungal growth. Repeated topical application in this model demonstrated that a lower-strength dose of NO could achieve the same efficacy as a higher-strength dose after 7 days. Together, these in vitro results demonstrate that NO-releasing treatments rapidly penetrate the nail plate and eradicate the fungal infection, representing promising novel topical therapies for the treatment of onychomycosis and other cutaneous fungal infections.
Assuntos
Antifúngicos/farmacologia , Óxido Nítrico/química , Onicomicose/microbiologia , Antifúngicos/química , Antifúngicos/uso terapêutico , Candida/efeitos dos fármacos , Epidermophyton/efeitos dos fármacos , Humanos , Malassezia/efeitos dos fármacos , Unhas/microbiologia , Onicomicose/tratamento farmacológico , Tinha dos Pés/microbiologia , Trichophyton/efeitos dos fármacosRESUMO
The heterogeneity and severity of certain autoimmune diseases and B-cell malignancies warrant simultaneous targeting of multiple disease-relevant signaling pathways. Dual inhibition of spleen tyrosine kinase (SYK) and Janus kinase (JAK) represents such a strategy and may elicit several benefits relative to selective kinase inhibition, such as gaining control over a broader array of disease etiologies, reducing probability of selection for bypass disease mechanisms, and the potential that an overall lower level suppression of individual targets may be sufficient to modulate disease activity. To this end, we provide data on the discovery and preclinical development of PRT062070 [4-(cyclopropylamino)-2-({4-[4-(ethylsulfonyl)piperazin-1-yl]phenyl}amino)pyrimidine-5-carboxamide hydrochloride], an orally active kinase inhibitor that demonstrates activity against SYK and JAK. Cellular assays demonstrated specific inhibitory activity against signaling pathways that use SYK and JAK1/3. Limited inhibition of JAK2 was observed, and PRT062070 did not inhibit phorbol 12-myristate 13-acetate-mediated signaling or activation in B and T cells nor T-cell antigen receptor-mediated signaling in T cells, providing evidence for selectivity of action. Potent antitumor activity was observed in a subset of B-cell lymphoma cell lines. After oral dosing, PRT062070 suppressed inflammation and autoantibody generation in a rat collagen-induced arthritis model and blocked B-cell activation and splenomegaly in a mouse model of chronic B-cell antigen receptor stimulation. PRT062070 is currently under evaluation in a phase I dose escalation study in patients with B-cell leukemia and lymphoma (NCT01994382), with proof-of-concept studies in humans planned to assess therapeutic potential in autoimmune and malignant diseases.
Assuntos
Artrite Experimental/tratamento farmacológico , Autoimunidade/efeitos dos fármacos , Modelos Animais de Doenças , Linfoma de Células B/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Pirimidinas/uso terapêutico , Sulfonas/uso terapêutico , Animais , Artrite Experimental/imunologia , Artrite Experimental/patologia , Autoimunidade/fisiologia , Bovinos , Relação Dose-Resposta a Droga , Feminino , Humanos , Linfoma de Células B/imunologia , Linfoma de Células B/patologia , Camundongos , Camundongos Endogâmicos BALB C , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/química , Pirimidinas/farmacologia , Distribuição Aleatória , Ratos , Ratos Endogâmicos Lew , Sulfonas/química , Sulfonas/farmacologia , Resultado do TratamentoRESUMO
B-cell receptor (BCR) associated kinases including spleen tyrosine kinase (SYK) contribute to the pathogenesis of B-cell malignancies. SYK is persistently phosphorylated in a subset of non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukemia (CLL), and SYK inhibition results in abrogation of downstream kinase activity and apoptosis. P505-15 (also known as PRT062607) is a novel, highly selective, and orally bioavailable small molecule SYK inhibitor (SYK IC(50) = 1 nM) with anti-SYK activity that is at least 80-fold greater than its affinity for other kinases. We evaluated the preclinical characteristics of P505-15 in models of NHL and CLL. P505-15 successfully inhibited SYK-mediated B-cell receptor signaling and decreased cell viability in NHL and CLL. Oral dosing in mice prevented BCR-mediated splenomegaly and significantly inhibited NHL tumor growth in a xenograft model. In addition, combination treatment of primary CLL cells with P505-15 plus fludarabine produced synergistic enhancement of activity at nanomolar concentrations. Our findings support the ongoing development of P505-15 as a therapeutic agent for B-cell malignancies. A dose finding study in healthy volunteers has been completed.
Assuntos
Antineoplásicos/farmacologia , Linfócitos B/efeitos dos fármacos , Cicloexilaminas/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Linfoma não Hodgkin/tratamento farmacológico , Proteínas Tirosina Quinases/antagonistas & inibidores , Pirimidinas/farmacologia , Vidarabina/análogos & derivados , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacocinética , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Linfócitos B/enzimologia , Linfócitos B/patologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cicloexilaminas/administração & dosagem , Cicloexilaminas/farmacocinética , Cicloexilaminas/uso terapêutico , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Citometria de Fluxo , Humanos , Leucemia Linfocítica Crônica de Células B/enzimologia , Leucemia Linfocítica Crônica de Células B/patologia , Linfoma não Hodgkin/enzimologia , Linfoma não Hodgkin/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos SCID , Fosforilação , Pirimidinas/administração & dosagem , Pirimidinas/farmacocinética , Pirimidinas/uso terapêutico , Baço/efeitos dos fármacos , Baço/enzimologia , Quinase Syk , Vidarabina/administração & dosagem , Vidarabina/farmacocinética , Vidarabina/farmacologia , Vidarabina/uso terapêutico , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Based on genetic studies that establish the role of spleen tyrosine kinase (Syk) in immune function, inhibitors of this kinase are being investigated as therapeutic agents for inflammatory diseases. Because genetic studies eliminate both adapter functions and kinase activity of Syk, it is difficult to delineate the effect of kinase inhibition alone as would be the goal with small-molecule kinase inhibitors. We tested the hypothesis that specific pharmacological inhibition of Syk activity retains the immunomodulatory potential of Syk genetic deficiency. We report here on the discovery of (4-(3-(2H-1,2,3-triazol-2-yl)phenylamino)-2-((1R,2S)-2-aminocyclohexylamino) pyrimidine-5-carboxamide acetate (P505-15), a highly specific and potent inhibitor of purified Syk (IC50 1-2 nM). In human whole blood, P505-15 potently inhibited B cell antigen receptor-mediated B cell signaling and activation (IC50 0.27 and 0.28 µM, respectively) and Fcε receptor 1-mediated basophil degranulation (IC50 0.15 µM). Similar levels of ex vivo inhibition were measured after dosing in mice (Syk signaling IC50 0.32 µM). Syk-independent signaling and activation were unaffected at much higher concentrations, demonstrating the specificity of kinase inhibition in cellular systems. Oral administration of P505-15 produced dose-dependent anti-inflammatory activity in two rodent models of rheumatoid arthritis. Statistically significant efficacy was observed at concentrations that specifically suppressed Syk activity by â¼67%. Thus specific Syk inhibition can mimic Syk genetic deficiency to modulate immune function, providing a therapeutic strategy in P505-15 for the treatment of human diseases.
Assuntos
Artrite Experimental/prevenção & controle , Cicloexilaminas/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Leucócitos/efeitos dos fármacos , Leucócitos/imunologia , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Tirosina Quinases/antagonistas & inibidores , Pirimidinas/farmacologia , Sinovite/prevenção & controle , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Artrite Experimental/complicações , Artrite Experimental/patologia , Linfócitos B/efeitos dos fármacos , Linfócitos B/imunologia , Linfócitos B/metabolismo , Basófilos/efeitos dos fármacos , Basófilos/imunologia , Biocatálise/efeitos dos fármacos , Sangue/efeitos dos fármacos , Sangue/imunologia , Sangue/metabolismo , Degranulação Celular/efeitos dos fármacos , Linhagem Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cicloexilaminas/administração & dosagem , Cicloexilaminas/farmacocinética , Cicloexilaminas/uso terapêutico , Modelos Animais de Doenças , Edema/complicações , Edema/patologia , Edema/prevenção & controle , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Feminino , Pé/patologia , Humanos , Concentração Inibidora 50 , Peptídeos e Proteínas de Sinalização Intracelular/efeitos dos fármacos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Leucócitos/metabolismo , Ativação Linfocitária/efeitos dos fármacos , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Estrutura Molecular , Fosforilação/efeitos dos fármacos , Células Precursoras de Linfócitos B/efeitos dos fármacos , Células Precursoras de Linfócitos B/imunologia , Células Precursoras de Linfócitos B/metabolismo , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/farmacocinética , Proteínas Tirosina Quinases/efeitos dos fármacos , Proteínas Tirosina Quinases/metabolismo , Pirimidinas/administração & dosagem , Pirimidinas/farmacocinética , Pirimidinas/uso terapêutico , Ratos , Ratos Endogâmicos LewRESUMO
Systematic SAR studies of in vitro factor Xa inhibitory activity around compound 1 were performed by modifying each of the three phenyl rings. A class of highly potent, selective, efficacious and orally bioavailable direct factor Xa inhibitors was discovered. These compounds were screened in hERG binding assays to examine the effects of substitution groups on the hERG channel affinity. From the leading compounds, betrixaban (compound 11, PRT054021) has been selected as the clinical candidate for development.
Assuntos
Anticoagulantes/síntese química , Anticoagulantes/farmacologia , Benzamidas/síntese química , Benzamidas/farmacologia , Descoberta de Drogas/métodos , Inibidores do Fator Xa , Piridinas/síntese química , Piridinas/farmacologia , Administração Oral , Animais , Anticoagulantes/administração & dosagem , Benzamidas/administração & dosagem , Domínio Catalítico/efeitos dos fármacos , Linhagem Celular , Cães , Relação Dose-Resposta a Droga , Canal de Potássio ERG1 , Canais de Potássio Éter-A-Go-Go/genética , Fator Xa/metabolismo , Humanos , Macaca fascicularis , Piridinas/administração & dosagem , Coelhos , RatosRESUMO
INTRODUCTION: Increasing use of factor Xa (FXa) inhibitors necessitates effective reversal agents to manage bleeding. Andexanet alfa, a novel modified recombinant human FXa, rapidly reverses the anticoagulation effects of direct and indirect FXa inhibitors. OBJECTIVE: To evaluate the ability of andexanet to reverse anticoagulation in vitro and reduce bleeding in rabbits administered edoxaban. MATERIALS AND METHODS: In vitro studies characterized the interaction of andexanet with edoxaban and its ability to reverse edoxaban-mediated anti-FXa activity. In a rabbit model of surgically induced, acute hemorrhage, animals received edoxaban vehicle+andexanet vehicle (control), edoxaban (1 mg/kg)+andexanet vehicle, edoxaban+andexanet (75 mg, 5-minute infusion, 20 minutes after edoxaban), or edoxaban vehicle+andexanet prior to injury. RESULTS: Andexanet bound edoxaban with high affinity similar to FXa. Andexanet rapidly and dose-dependently reversed the effects of edoxaban on FXa activity and coagulation pharmacodynamic parameters in vitro. In edoxaban-anticoagulated rabbits, andexanet reduced anti-FXa activity by 82% (from 548±87 to 100±41 ng/ml; P<0.0001), mean unbound edoxaban plasma concentration by ~80% (from 100±10 to 21±6 ng/ml; P<0.0001), and blood loss by 80% vs. vehicle (adjusted for control, 2.6 vs. 12.9 g; P = 0.003). The reduction in blood loss correlated with the decrease in anti-FXa activity (r = 0.6993, P<0.0001) and unbound edoxaban (r = 0.5951, P = 0.0035). CONCLUSION: These data demonstrate that andexanet rapidly reversed the anticoagulant effects of edoxaban, suggesting it could be clinically valuable for the management of acute and surgery-related bleeding. Correlation of blood loss with anti-FXa activity supports the use of anti-FXa activity as a biomarker for assessing anticoagulation reversal in clinical trials.
Assuntos
Anticoagulantes/farmacologia , Antídotos/farmacologia , Coagulação Sanguínea/efeitos dos fármacos , Inibidores do Fator Xa/farmacologia , Fator Xa/farmacologia , Hemorragia/tratamento farmacológico , Piridinas/farmacologia , Proteínas Recombinantes/farmacologia , Tiazóis/farmacologia , Animais , Modelos Animais de Doenças , Hemorragia/induzido quimicamente , Masculino , CoelhosRESUMO
Direct factor Xa (FXa) inhibitors lack a specific reversal agent for emergencies such as major bleeding or urgent surgery. Andexanet alfa, a modified, catalytically inactive, recombinant human FXa derivative, reverses anticoagulant effect by binding and sequestering FXa inhibitors. This original report of safety and dose-finding, phase 1 and 2 randomized, double-blind, placebo-controlled studies, investigated various doses of andexanet in healthy volunteers. Phase 1 evaluated the safety and pharmacokinetics of andexanet (n = 24) or placebo (n = 8). In phase 2, andexanet (n = 36) or placebo (n = 18) was administered following steady-state apixaban dosing (5 mg twice daily for 6 days); safety, pharmacokinetics, and pharmacodynamics were assessed. Andexanet plasma concentration increased proportionally with dose, with rapid elimination (terminal elimination half-life, 4.35-7.5 hours). Following apixaban treatment, andexanet rapidly (≤2 minutes) and dose dependently reduced unbound apixaban concentration vs placebo (51% to 89% vs 5% reduction; all P < .05), decreased anti-FXa activity (67.8% to 95.0% vs 7.1% reduction; all P < .05), and restored thrombin generation in 67% to 100% vs 6% of subjects (all P < .01), maintaining these effects during continuous 45- and 120-minute infusions. Andexanet was well tolerated. Nine subjects had mild/moderate infusion reactions not associated with hemodynamic changes or respiratory compromise that generally resolved without intervention or dose reduction. There were no thrombotic events or other serious safety issues. In conclusion, andexanet reversed apixaban-mediated effects on pharmacodynamic markers of anticoagulation in healthy volunteers within minutes after administration and for the duration of infusion. This trial was registered at www.clinicaltrials.gov as #NCT01758432.
RESUMO
Glioblastoma multiforme, the most common form of malignant brain tumor,is resistant to all forms of therapy and causes death within 9-12 months of diagnosis. Glioblastomas are known to contain numerous genetic and physiological alterations affecting cell survival and proliferation; one of the most common alterations being platelet-derived growth factor (PDGF) autocrine signaling characterized by coexpression of PDGF and its receptor. The PDGF family consists of four members, PDGF-A, -B, -C, and -D, that signal through the alpha and beta PDGF receptor (PDGFR) tyrosine kinases. Numerous studies have demonstrated expression of PDGF-A, PDGF-B, and the PDGFRs in gliomablastomas, but such studies have not been conducted for the newly identified PDGF-C and -D. Therefore, we examined the expression of all PDGF ligands and receptors in 11 glioma cell lines and 5 primary glioblastoma tumor tissues by quantitative reverse transcription-PCR. Expression of PDGF/PDGFR pairs that are known to functionally interact were identified in all of the samples. Interestingly, PDGF-C expression was ubiquitous in brain tumor cells and tissues but was very low or absent in normal adult and fetal brain. PDGF-D was expressed in 10 of 11 brain tumor cell lines and 3 of 5 primary brain tumor samples. As a strategy for blocking PDGFR signaling, CT52923, a potent selective small molecule piperazinyl quinazoline kinase inhibitor of the PDGFR, was identified. In model systems using NIH/3T3 cells, CT52923 blocked PDGF autocrine-mediated phosphorylation of PDGFR, Akt, and mitogen-activated protein kinase (MAPK), while having no effect on v-fms or V12-ras-mediated Akt or extracellular signal-regulated protein kinase (Erk) phosphorylation. More importantly, p.o. administration of CT52923 to nude mice caused a significant 61% reduction (P < 0.006) in tumor growth of NIH/3T3 cells transformed by PDGF, whereas tumor formation by cells expressing v-fms was unaffected. We next characterized PDGF autocrine signaling in five glioblastoma cell lines. In all of the cases, PDGF autocrine signaling was evident because treatment with 1-10 microM CT52923 inhibited PDGFR autophosphorylation when present at a detectable level and blocked downstream Akt and/or Erk phosphorylation. The functional significance of PDGF autocrine signaling in these cells was demonstrated by the fact that the CT52923 inhibited soft agar colony formation, and, when given p.o. to nude mice, it effectively reduced tumor formation by 44% (P < 0.0019) after s.c. injection of C6 glioblastoma cells. This study of glioblastoma cells and primary tissues is the first to implicate PDGF-C and -D in brain tumor formation and confirms the existence of autocrine signaling by PDGF-A and -B. More importantly, treatment with the PDGFR antagonist CT52923 inhibited survival and/or mitogenic pathways in all of the glioblastoma cell lines tested and prevented glioma formation in a nude mouse xenograft model. Together these findings demonstrate the potential therapeutic utility of this class of compounds for the treatment of glioblastoma.
Assuntos
Neoplasias Encefálicas/patologia , Glioblastoma/patologia , Linfocinas , Piperazinas/farmacologia , Fator de Crescimento Derivado de Plaquetas/fisiologia , Proteínas Serina-Treonina Quinases , Quinazolinas/farmacologia , Células 3T3/citologia , Células 3T3/efeitos dos fármacos , Células 3T3/metabolismo , Animais , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/metabolismo , Divisão Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Glioblastoma/tratamento farmacológico , Glioblastoma/metabolismo , Humanos , Ligantes , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/fisiologia , Camundongos , Camundongos Nus , Quinases de Proteína Quinase Ativadas por Mitógeno/antagonistas & inibidores , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Fosforilação/efeitos dos fármacos , Fator de Crescimento Derivado de Plaquetas/metabolismo , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-akt , Ratos , Receptores do Fator de Crescimento Derivado de Plaquetas/antagonistas & inibidores , Receptores do Fator de Crescimento Derivado de Plaquetas/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologiaRESUMO
OBJECTIVE: In this study we test the hypothesis that blood/plasma-based prothrombinase assays, rather than inhibition of purified factor Xa (fXa), are predictive of in vivo antithrombotic activity. METHODS AND RESULTS: Six fXa inhibitors with equivalent nanomolar Ki were studied in thrombin generation assays using human plasma/blood and endogenous macromolecular substrate. In all assays, benzamidine inhibitors were more potent (100 to 800 nmol/L) than the aminoisoquinolines (5 to 58 micromol/L) or neutral inhibitors (3 to 10 micromol/L). A similar rank order of compound inhibition was also seen in purified prothrombinase assays as well as in a rabbit model of deep vein thrombosis. CONCLUSIONS: Assays using prothrombinase with protein substrates are better predictors of in vivo efficacy than fXa Ki using amidolytic substrates.
Assuntos
Benzamidinas/farmacologia , Inibidores Enzimáticos/farmacologia , Inibidores do Fator Xa , Fibrinolíticos/farmacologia , Isoquinolinas/farmacologia , Protrombina/metabolismo , Tromboplastina/antagonistas & inibidores , Animais , Sítios de Ligação/efeitos dos fármacos , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/classificação , Fibrinolíticos/classificação , Humanos , Masculino , Estrutura Molecular , Sensibilidade e Especificidade , Especificidade por Substrato , Trombina/biossíntese , Trombose Venosa/prevenção & controleRESUMO
We have previously found that the 4-[4-(N-substituted carbamoyl)-1-piperazinyl]-6,7-dimethoxyquinazolines can function as potent and selective inhibitors of platelet-derived growth factor receptor (PDGFR) phosphorylation. A series of highly potent, specific, orally active, small molecule kinase inhibitors directed against members of PDGFR receptor have been developed through modifications of the novel quinazoline template I. Systematic modifications in the A-bicyclic ring and D-rings of protype I were carried out to afford potent analogues, which display IC(50) values of <250 nM in cellular betaPDGFR phosphorylation assays. An optimized analogue in this series, 75 (CT53518), inhibits Flt-3, betaPDGFR, and c-Kit receptor phosphorylation with IC(50) values of 50-200 nM, whereas 15-20-fold less potent activity against CSF-1R was observed. This analogue also inhibits autophosphorylation of Flt-3 ligand-stimulated wild-type Flt-3 and a constitutively activated Flt-3/internal tandem duplication (ITD) with IC(50) values of 30-100 nM. Through this optimization process, 75 was found to be metabolically stable and has desirable pharmacokinetic properties in all animal species studied (F% > 50%, T(1/2) > 8 h). Oral administration of 75 promotes mice survival and significantly delayed disease progression in a Flt-3/ITD-mediated leukemia mouse model and shows efficacy in a nude mouse model of chronic myelomonocytic leukemia.
Assuntos
Inibidores Enzimáticos/síntese química , Piperazinas/síntese química , Quinazolinas/síntese química , Receptores do Fator de Crescimento Derivado de Plaquetas/antagonistas & inibidores , Administração Oral , Animais , Disponibilidade Biológica , Cães , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Feminino , Humanos , Técnicas In Vitro , Leucemia Experimental/tratamento farmacológico , Leucemia Mielomonocítica Crônica/tratamento farmacológico , Macaca fascicularis , Masculino , Camundongos , Camundongos Nus , Microssomos Hepáticos/metabolismo , Mutação , Fosforilação , Piperazinas/química , Piperazinas/farmacologia , Plasma , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-kit/metabolismo , Quinazolinas/química , Quinazolinas/farmacologia , Ratos , Ratos Endogâmicos Lew , Receptores Proteína Tirosina Quinases/genética , Receptores Proteína Tirosina Quinases/metabolismo , Receptor beta de Fator de Crescimento Derivado de Plaquetas/metabolismo , Receptores do Fator de Crescimento Derivado de Plaquetas/metabolismo , Relação Estrutura-Atividade , Células Tumorais Cultivadas , Tirosina Quinase 3 Semelhante a fmsRESUMO
In our efforts to develop orally active GPIIb-IIIa antagonists with improved pharmaceutical properties, we have utilized a novel 2,8-diazaspiro[4.5]decane scaffold as a template. We describe here our investigation of a variety of templates including spiropiperidinyl-gamma-lactams, spiropiperidinylimide, spiropiperidinylureas, and spiropiperidinylhydantoins. With the appropriate acidic and basic pharmacophores in place, each template yielded analogues with potent GPIIb-IIIa inhibitory activity. One of the compounds, 59 (CT50787), was also used to demonstrate for the first time the use of a pharmacological agent which is alphaIIbbeta3 specific to display biological activity in a lower species such as mouse and to extend bleeding times. Evaluation of the pharmacokinetic properties of selected compounds from each series in rat, dog, and cynomolgus monkey has led to the identification of 22 (CT51464), a double prodrug, with excellent pharmacokinetic properties. It exhibited good pharmacokinetic profile across species (F% = 33 (Cyno), 73 (dog), 22 (rat); t(1/2)(beta)() = 14.2 h (Cyno), 8.97 h (dog), 1.81 h (rat)). The biologically active form, 23 (CT50728), displayed inhibition of platelet aggregation in platelet rich plasma (PRP) with an IC(50) value of 53 nM in citrate buffer, 110 nM in PPACK anticoagulated PRP, and 4 nM in solid-phase GPIIb-IIIa competition binding assay (ELISA). Both 23 and 22 were stable in human liver microsomes, did not inhibit the P450 3A4 isozyme, and had low protein binding (18.22% for 23) and a desirable log P (0.45 +/- 0.06 for 22, and -0.91 +/- 0.32 for 23). It is predicted that the high oral bioavailability for these compounds in multiple species should translate into lower intra- and intersubject variability in man. The long plasma half-life of the lead is consistent with once or twice daily administration for chronic therapy. Analogue 22 (CT51464) thus appears to be a promising oral GPIIb-IIIa inhibitor with significantly improved pharmacokinetic properties over the previously described clinical candidates and may be found useful in the treatment of arterial occlusive disorders.
Assuntos
Alcanos/síntese química , Compostos Aza/síntese química , Hidroxilaminas/síntese química , Inibidores da Agregação Plaquetária/síntese química , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/antagonistas & inibidores , Pró-Fármacos/síntese química , Compostos de Espiro/síntese química , Administração Oral , Alcanos/farmacocinética , Alcanos/farmacologia , Animais , Compostos Aza/farmacocinética , Compostos Aza/farmacologia , Ligação Competitiva , Disponibilidade Biológica , Tempo de Sangramento , Cães , Humanos , Hidantoínas/síntese química , Hidantoínas/farmacocinética , Hidantoínas/farmacologia , Hidroxilaminas/farmacocinética , Hidroxilaminas/farmacologia , Técnicas In Vitro , Lactamas/síntese química , Lactamas/farmacocinética , Lactamas/farmacologia , Macaca fascicularis , Camundongos , Inibidores da Agregação Plaquetária/farmacocinética , Inibidores da Agregação Plaquetária/farmacologia , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/metabolismo , Pró-Fármacos/farmacocinética , Pró-Fármacos/farmacologia , Ratos , Ratos Sprague-Dawley , Compostos de Espiro/farmacocinética , Compostos de Espiro/farmacologia , Relação Estrutura-Atividade , Ureia/análogos & derivados , Ureia/síntese química , Ureia/farmacocinética , Ureia/farmacologiaRESUMO
OBJECTIVE: To evaluate the effects of the anticoagulant betrixaban on individual heart rate-corrected QT (QTcI). RESEARCH DESIGN AND METHODS: Ninety-six healthy adults were randomly assigned to single-dose betrixaban 80 and 140 mg (therapeutic and supratherapeutic doses, respectively), placebo, and moxifloxacin 400 mg (positive control) in a four-period crossover study. Electrocardiograms were recorded at pre-dose and post-dose hours 1, 2, 3, 4, 5, 6, 8, 12, 16 and 24. MAIN OUTCOMES MEASURES: An analysis of covariance determined the placebo-corrected, time-matched mean change from baseline QTcI at the 95% upper confidence interval (UCI; one-sided). The pre-specified clinically significant change for betrixaban-treated groups was > 10 ms (95% UCI, one-sided). Subjects were monitored for safety and tolerability. RESULTS: Mean QTcI change was < 10 ms for both betrixaban groups at all time points; expected changes were observed for moxifloxacin, establishing assay sensitivity. Correlation between betrixaban plasma concentration and QTcI duration confirmed the absence of effect on QT. CONCLUSIONS: Betrixaban at therapeutic and supratherapeutic doses did not cause clinically relevant changes in QTcI intervals or other electrocardiographic parameters. Betrixaban was well tolerated.
Assuntos
Anticoagulantes/uso terapêutico , Benzamidas/uso terapêutico , Eletrocardiografia/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Síndrome do QT Longo/prevenção & controle , Piridinas/uso terapêutico , Administração Oral , Adolescente , Adulto , Antibacterianos/efeitos adversos , Anticoagulantes/efeitos adversos , Compostos Aza/efeitos adversos , Benzamidas/efeitos adversos , Estudos Cross-Over , Método Duplo-Cego , Feminino , Fluoroquinolonas , Humanos , Masculino , Pessoa de Meia-Idade , Moxifloxacina , Piridinas/efeitos adversos , Quinolinas/efeitos adversos , Adulto JovemRESUMO
Inhibitors of coagulation factor Xa (fXa) have emerged as a new class of antithrombotics but lack effective antidotes for patients experiencing serious bleeding. We designed and expressed a modified form of fXa as an antidote for fXa inhibitors. This recombinant protein (r-Antidote, PRT064445) is catalytically inactive and lacks the membrane-binding γ-carboxyglutamic acid domain of native fXa but retains the ability of native fXa to bind direct fXa inhibitors as well as low molecular weight heparin-activated antithrombin III (ATIII). r-Antidote dose-dependently reversed the inhibition of fXa by direct fXa inhibitors and corrected the prolongation of ex vivo clotting times by such inhibitors. In rabbits treated with the direct fXa inhibitor rivaroxaban, r-Antidote restored hemostasis in a liver laceration model. The effect of r-Antidote was mediated by reducing plasma anti-fXa activity and the non-protein bound fraction of the fXa inhibitor in plasma. In rats, r-Antidote administration dose-dependently and completely corrected increases in blood loss resulting from ATIII-dependent anticoagulation by enoxaparin or fondaparinux. r-Antidote has the potential to be used as a universal antidote for a broad range of fXa inhibitors.
Assuntos
Anticoagulantes/antagonistas & inibidores , Antídotos/farmacologia , Inibidores do Fator Xa , Proteínas Recombinantes/farmacologia , Animais , Benzamidas/antagonistas & inibidores , Relação Dose-Resposta a Droga , Enoxaparina/antagonistas & inibidores , Fator Xa/farmacologia , Fondaparinux , Hemorragia/tratamento farmacológico , Hemostasia/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Morfolinas/antagonistas & inibidores , Polissacarídeos/antagonistas & inibidores , Pirazóis/antagonistas & inibidores , Piridinas/antagonistas & inibidores , Piridonas/antagonistas & inibidores , Coelhos , Ratos , Ratos Sprague-Dawley , Rivaroxabana , Tiofenos/antagonistas & inibidoresRESUMO
4-[4-(N-Substituted-thio-carbamoyl)-1-piperazinyl]-6-methoxy-7-alkoxyamino-quinazoline derivatives such as 14 (CT53986) have been identified to be potent and selective inhibitors of the phosphorylation of PDGFR. SAR-investigations are described in the arylamine segment, C-7 appendage, and the thiourea moiety. Bioisosteres of thiourea (cyanoguanidine), and of quinazoline (quinoline-3-carbonitrile) were synthesized and are compared for their in vitro inhibitory activity. PK profiles of the optimized compounds in rat, dog, and cynomolgus monkey are described.
Assuntos
Receptores do Fator de Crescimento Derivado de Plaquetas/antagonistas & inibidores , Tioureia/síntese química , Administração Oral , Animais , Disponibilidade Biológica , Cães , Macaca fascicularis , Quinazolinas/síntese química , Quinazolinas/farmacologia , Ratos , Relação Estrutura-Atividade , Tioureia/farmacologiaRESUMO
Anthranilamides 4 and 5 were designed and synthesized as selective and orally bioavailable factor Xa inhibitors. Structural modifications aimed at lowering their lipophilicity were performed at the central phenyl ring and at the S4 binding biphenyl region by incorporating water solublizing substituents. The resulting compounds (e.g., 7, 8, 14, 30a, and 32b) are highly potent in vitro, and show improved activity in human plasma-based thrombin generation assay.
Assuntos
Amidas/síntese química , Amidas/farmacologia , Inibidores do Fator Xa , ortoaminobenzoatos/síntese química , ortoaminobenzoatos/farmacologia , Administração Oral , Animais , Disponibilidade Biológica , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos , Humanos , Estrutura Molecular , Ratos , Ratos Sprague-Dawley , Relação Estrutura-Atividade , Trombose/tratamento farmacológico , Trombose/prevenção & controleRESUMO
Compound 2 containing an aminomethylbenzoyl moiety as the S4 binding motif was synthesized in order to modulate hydrophlicity of anthranilamide-based factor Xa inhibitors with substituted biphenyl P4 groups. Structure-activity relationship studies around 2 have led to a series of potent factor Xa inhibitors which are highly active in the human plasma-based thrombin generation assay with 2XTG values less than 1 microM. Compound 55 shows strong antithrombotic activity in our rabbit deep vein thrombosis model, and also exhibits good oral bioavailability and a long half life in rats.
Assuntos
Amidas/síntese química , Amidas/farmacologia , Inibidores do Fator Xa , ortoaminobenzoatos/síntese química , ortoaminobenzoatos/farmacologia , Administração Oral , Animais , Disponibilidade Biológica , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Desenho de Fármacos , Humanos , Estrutura Molecular , Coelhos , Ratos , Ratos Sprague-Dawley , Relação Estrutura-Atividade , Trombose/tratamento farmacológicoRESUMO
A class of N,N-dialkylated 4-(4-arylsulfonylpiperazine-1-carbonyl)-benzamidines and 4-((4-arylsulfonyl)-2-oxo-piperazin-1-ylmethyl)-benzamidines has been discovered as potent factor Xa inhibitors with desirable in vitro and in vivo anticoagulant activity, but with low oral bioavailability. The 5-chloroindole and 6-chlorobenzo[b]thiophene groups are optimal as the factor Xa S1 binding elements. The strategy of incorporating a side chain on the piperazine nucleus to enhance binding affinity has been examined.
Assuntos
Benzamidinas/farmacologia , Inibidores do Fator Xa , Inibidores de Serina Proteinase/farmacologia , Benzamidinas/química , Benzamidinas/farmacocinética , Disponibilidade Biológica , Inibidores de Serina Proteinase/química , Inibidores de Serina Proteinase/farmacocinéticaRESUMO
A series of benzoxazinone derivatives was designed and synthesized as factor Xa inhibitors. We demonstrated that the naphthyl moiety in the aniline-based compounds 1 and 2 can be replaced with benzene-fused heterobicycles and biaryls to give factor Xa inhibitors with improved trypsin selectivity. The P4 modifications lead to monoamidines which are moderately active. The benzoxazinones 41-45 are potent against factor Xa, retain the improved trypsin selectivity of the corresponding aniline-based compounds, and show strong antithrombotic effect dose responsively.