RESUMEN
NVR 3-778 is the first capsid assembly modulator (CAM) that has demonstrated antiviral activity in hepatitis B virus (HBV)-infected patients. NVR 3-778 inhibited the generation of infectious HBV DNA-containing virus particles with a mean antiviral 50% effective concentration (EC50) of 0.40 µM in HepG2.2.15 cells. The antiviral profile of NVR 3-778 indicates pan-genotypic antiviral activity and a lack of cross-resistance with nucleos(t)ide inhibitors of HBV replication. The combination of NVR 3-778 with nucleos(t)ide analogs in vitro resulted in additive or synergistic antiviral activity. Mutations within the hydrophobic pocket at the dimer-dimer interface of the core protein could confer resistance to NVR 3-778, which is consistent with the ability of the compound to bind to core and to induce capsid assembly. By targeting core, NVR 3-778 inhibits pregenomic RNA encapsidation, viral replication, and the production of HBV DNA- and HBV RNA-containing particles. NVR 3-778 also inhibited de novo infection and viral replication in primary human hepatocytes with EC50 values of 0.81 µM against HBV DNA and between 3.7 and 4.8 µM against the production of HBV antigens and intracellular HBV RNA. NVR 3-778 showed favorable pharmacokinetics and safety in animal species, allowing serum levels in excess of 100 µM to be achieved in mice and, thus, enabling efficacy studies in vivo The overall preclinical profile of NVR 3-778 predicts antiviral activity in vivo and supports its further evaluation for safety, pharmacokinetics, and antiviral activity in HBV-infected patients.
Asunto(s)
Antivirales/farmacología , Benzamidas/farmacología , Cápside/efectos de los fármacos , ADN Viral/antagonistas & inhibidores , Virus de la Hepatitis B/efectos de los fármacos , Hepatitis B/tratamiento farmacológico , Piperidinas/farmacología , ARN Viral/antagonistas & inhibidores , Animales , Antígenos Virales/genética , Antígenos Virales/metabolismo , Antivirales/sangre , Antivirales/química , Antivirales/farmacocinética , Benzamidas/sangre , Benzamidas/química , Benzamidas/farmacocinética , Cápside/química , Cápside/metabolismo , ADN Viral/genética , ADN Viral/metabolismo , Evaluación Preclínica de Medicamentos , Femenino , Células Hep G2 , Hepatitis B/virología , Virus de la Hepatitis B/genética , Virus de la Hepatitis B/metabolismo , Hepatocitos/efectos de los fármacos , Hepatocitos/patología , Hepatocitos/virología , Humanos , Masculino , Ratones , Pruebas de Sensibilidad Microbiana , Piperidinas/sangre , Piperidinas/química , Piperidinas/farmacocinética , Cultivo Primario de Células , ARN Viral/genética , ARN Viral/metabolismo , Proteínas del Núcleo Viral/antagonistas & inhibidores , Proteínas del Núcleo Viral/genética , Proteínas del Núcleo Viral/metabolismo , Replicación Viral/efectos de los fármacosRESUMEN
Oseltamivir and peramivir are being considered for combination treatment of serious influenza virus infections in humans. Both compounds are influenza virus neuraminidase inhibitors, and since peramivir binds tighter to the enzyme than oseltamivir carboxylate (the active form of oseltamivir), the possibility exists that antagonistic interactions might result when using the two compounds together. To study this possibility, combination chemotherapy experiments were conducted in vitro and in mice infected with influenza A/NWS/33 (H1N1) virus. Treatment of infected MDCK cells was performed with combinations of oseltamivir carboxylate and peramivir at 0.32-100µM for 3 days, followed by virus yield determinations. Additive drug interactions with a narrow region of synergy were found using the MacSynergy method. In a viral neuraminidase assay with combinations of inhibitors at 0.01-10nM, no significant antagonistic or synergistic interactions were observed across the range of concentrations. Infected mice were treated twice daily for 5 days starting 2h prior to virus challenge using drug doses of 0.05-0.4mg/kg/day. Consistent and statistically significant increases in the numbers of survivors were seen when twice daily oral oseltamivir (0.4mg/kg/day) was combined with twice daily intramuscular peramivir (0.1 and 0.2mg/kg/day) compared to single drug treatments. The data demonstrate that combinations of oseltamivir and peramivir perform better than suboptimal doses of each compound alone to treat influenza infections in mice. Treatment with these two compounds should be considered as an option.
Asunto(s)
Antivirales/uso terapéutico , Ciclopentanos/uso terapéutico , Guanidinas/uso terapéutico , Subtipo H1N1 del Virus de la Influenza A/efectos de los fármacos , Neuraminidasa/antagonistas & inhibidores , Infecciones por Orthomyxoviridae/tratamiento farmacológico , Oseltamivir/uso terapéutico , Ácidos Carbocíclicos , Animales , Antivirales/administración & dosificación , Antivirales/farmacología , Línea Celular , Ciclopentanos/administración & dosificación , Ciclopentanos/farmacología , Modelos Animales de Enfermedad , Evaluación Preclínica de Medicamentos , Interacciones Farmacológicas , Quimioterapia Combinada , Guanidinas/administración & dosificación , Guanidinas/farmacología , Humanos , Ratones , Ratones Endogámicos BALB C , Infecciones por Orthomyxoviridae/virología , Oseltamivir/administración & dosificación , Oseltamivir/farmacologíaRESUMEN
We report the design, synthesis and evaluation of a family of ca 50 phosphoramidate ProTides of the potent anti-HCV compound 4'-azidocytidine (R1479), with variation on the ester, amino acid and aryl moiety of the ProTide. Sub-muM inhibitors of HCV emerge. The compounds are all non-cytotoxic in the replicon assay. We herein report detailed SARs for each of the regions of the ProTide.
Asunto(s)
Antivirales/síntesis química , Química Farmacéutica/métodos , Citidina/análogos & derivados , Hepacivirus/metabolismo , Hepatitis C/tratamiento farmacológico , Tecnología Farmacéutica/métodos , Aminoácidos/química , Antivirales/farmacología , Citidina/síntesis química , Citidina/farmacología , Diseño de Fármacos , Evaluación Preclínica de Medicamentos , Humanos , Modelos Químicos , Profármacos , Replicón/efectos de los fármacos , Replicación ViralRESUMEN
A series of 4'-substituted ribonucleoside derivatives has been prepared and evaluated for inhibition of hepatitis C virus (HCV) RNA replication in cell culture. The most potent and non-cytotoxic derivative was compound 28 (4'-azidocytidine, R1479) with an IC(50) of 1.28 microM in the HCV replicon system. The triphosphate of compound 28 was prepared and shown to be an inhibitor of RNA synthesis mediated by NS5B (IC(50)=320 nM), the RNA polymerase encoded by HCV. Data on related analogues have been used to generate some preliminary requirements for activity within this series of nucleosides.