Discovery of direct-acting antiviral agents with a graphene-based fluorescent nanosensor.
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ABSTRACT:
SUBMITTER: Park SJ
PROVIDER: S-EPMC7259931 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Hepatitis C virus (HCV) has emerged as a major viral pandemic over the past two decades, infecting 170 million individuals, which equates to approximately 3% of the world's population. The prevalence of HCV varies according to geographic region, being highest in developing countries such as Egypt. HCV has a high tendency to induce chronic progressive liver damage in the form of hepatic fibrosis, cirrhosis, or liver cancer. To date, there is no vaccine against HCV infection. Combination therapy comprising PEGylated interferon-alpha and ribavirin has been the standard of care for patients with chronic hepatitis C for more than a decade. However, many patients still do not respond to therapy or develop adverse events. Recently, direct antiviral agents such as protease inhibitors, polymerase inhibitors, or NS5A inhibitors have been used to augment PEGylated interferon and ribavirin, resulting in better efficacy, better tolerance, and a shorter treatment duration. However, most clinical trials have focused on assessing the efficacy and safety of direct antiviral agents in patients with genotype 1, and the response of other HCV genotypes has not been elucidated. Moreover, the prohibitive costs of such triple therapies will limit their use in patients in developing countries where most of the HCV infection exists. Understanding the host and viral factors associated with viral clearance is necessary for individualizing therapy to maximize sustained virologic response rates, prevent progression to liver disease, and increase the overall benefits of therapy with respect to its costs. Genome wide studies have shown significant associations between a set of polymorphisms in the region of the interleukin-28B (IL28B) gene and natural clearance of HCV infection or after PEGylated interferon-alpha and ribavirin treatment with and without direct antiviral agents. This paper synthesizes the recent advances in the pharmacogenetics of HCV infection in the era of triple therapies.
| S-EPMC4075960 | biostudies-literature
Project description:Chronic infection with hepatitis C virus (HCV) is a major global health problem; there are approximately 120 to 130 million chronic infections worldwide. Since the discovery of HCV 24 years ago, there has been a relentless effort to develop successful antiviral therapies. Studies of interferon-?-based therapies have helped define treatment parameters, and these treatment strategies have cured a substantial percentage of patients. However, interferon-? must be injected; there are problems with tolerability, adherence, and incomplete response in a large percentage of patients. New drug candidates designed to target the virus or the host have recently been introduced at an unprecedented pace. In phase I-III studies, these agents have exceeded expectations and achieved rates of response previously not thought possible. We are, therefore, entering a new era of therapy for HCV infection and interferon independence.
| S-EPMC4049632 | biostudies-literature
Project description:ImportanceRecent reports based on the US Food and Drug Administration's voluntary Adverse Events Reporting System raised questions about the safety of direct-acting antivirals (DAAs) for treatment of the hepatitis C virus (HCV).ObjectiveTo assess the rates of adverse events in patients with HCV infection exposed to DAAs compared with those not exposed.Design, setting, and participantsA retrospective cohort study calculated unadjusted adverse event rates for exposed vs unexposed time, using claims and clinical data from 3 health systems between January 1, 2012, and December 31, 2017. Of 82 419 eligible adults, a total of 33 808 who met eligibility criteria (age, 18-88 years; HCV quantitative result or genotype from 2012 or later; continuously enrolled; naive to DAA treatment at baseline) were included. Marginal structural modeling methods were used to adjust time-to-event analyses for characteristics that are associated with both outcomes and probability of treatment.Interventions or exposuresExposure to DAAs compared with no DAA exposure.Main outcomes and measuresDeath, multiple organ failure, liver cancer, hepatic decompensation, acute-on-chronic liver event, acute myocardial infarction, ischemic or hemorrhagic stroke, arrhythmia, acute kidney failure, nonliver cancer, hepatitis B reactivation, hospitalizations, and emergency department visits.ResultsOf the 33 808 patients who met all inclusion criteria, 20 899 (61.8%) were men; mean (SD) age was 57.2 (10.6) years. In unadjusted analyses, DAA exposure was associated with significantly lower rates of death (10.7 vs 33.7 events per 1000 person-years; rate ratio [RR], 0.32, 95% CI, 0.25-0.40). Seven other unadjusted adverse clinical events ratios were below 70% and statistically significant favoring the DAA group: multiple organ failure (RR, 0.56; 95% CI, 0.44-0.72), liver cancer (RR, 0.62; 95% CI, 0.48-0.80), hepatic decompensation (RR, 0.62; 95% CI, 0.52-0.73), acute-on-chronic liver event (RR, 0.68; 95% CI, 0.56-0.84), acute myocardial infarction (RR, 0.64; 95% CI, 0.42-0.97), ischemic stroke (RR, 0.63; 95% CI, 0.42-0.95), and hemorrhagic stroke (RR, 0.47; 95% CI, 0.25-0.89); none favored the non-DAA group. In the marginal structural modeling-adjusted analysis, DAA exposure was associated with statistically significant lower odds of adverse events than non-DAA exposure for death (adjusted odds ratio [aOR], 0.42; 95% CI, 0.30-0.59), multiple organ failure (aOR, 0.67; 95% CI, 0.49-0.90), hepatic decompensation (aOR, 0.61; 95% CI, 0.49-0.76), acute-on-chronic liver event (aOR, 0.71; 95% CI, 0.56-0.91), and arrhythmia (aOR, 0.47; 95% CI, 0.25-0.88).Conclusions and relevanceDirect-acting antiviral exposure may not be associated with higher rates of any serious adverse events, including those related to liver, kidney, and cardiovascular systems. Safety concerns based on previous reports did not appear to be supported in this study with more comprehensive data and rigorous statistical methods.
| S-EPMC6563580 | biostudies-literature
Project description:Around 71 million people are chronically infected with HCV worldwide. HCV antiviral drug development has been remarkable. The availability of pangenotypic direct-acting antivirals with excellent efficacy and good tolerability profiles offer a unique opportunity to achieve HCV elimination worldwide. IFN-free DAA combinations can now cure HCV in more than 95% of patients with HCV infection after 8-12 weeks of treatment. Programmes to eliminate HCV must include increased screening (risk-based and universal), linkage to care, as well as increased access to treatment worldwide. In this paper, we will review the available data on recently approved direct-acting antiviral agents, with sustained virological response that reaches almost 100%.
| S-EPMC7713514 | biostudies-literature
Project description:Hepatitis C virus (HCV) is transmitted between hepatocytes via classical cell entry but also uses direct cell-cell transfer to infect neighboring hepatocytes. Viral cell-cell transmission has been shown to play an important role in viral persistence allowing evasion from neutralizing antibodies. In contrast, the role of HCV cell-cell transmission for antiviral resistance is unknown. Aiming to address this question we investigated the phenotype of HCV strains exhibiting resistance to direct-acting antivirals (DAAs) in state-of-the-art model systems for cell-cell transmission and spread. Using HCV genotype 2 as a model virus, we show that cell-cell transmission is the main route of viral spread of DAA-resistant HCV. Cell-cell transmission of DAA-resistant viruses results in viral persistence and thus hampers viral eradication. We also show that blocking cell-cell transmission using host-targeting entry inhibitors (HTEIs) was highly effective in inhibiting viral dissemination of resistant genotype 2 viruses. Combining HTEIs with DAAs prevented antiviral resistance and led to rapid elimination of the virus in cell culture model. In conclusion, our work provides evidence that cell-cell transmission plays an important role in dissemination and maintenance of resistant variants in cell culture models. Blocking virus cell-cell transmission prevents emergence of drug resistance in persistent viral infection including resistance to HCV DAAs.
| S-EPMC4022730 | biostudies-literature
Project description:UnlabelledHepatitis C virus (HCV) is the most common cause of mixed cryoglobulinemia syndrome (MCS). The efficacy and safety of all-oral direct-acting antiviral (DAA) therapy in HCV-associated MCS (HCV-MCS) is largely unknown. The authors studied case series of patients with HCV-MCS who were treated with sofosbuvir-based regimens and historical controls treated with pegylated interferon and ribavirin in a single health care network. HCV-MCS was defined by circulating cryoglobulin associated with systemic vasculitis symptoms. Renal involvement (n = 7) was established by kidney biopsy (n = 5) or by two or more of the following clinical findings: reduced kidney function, proteinuria, or hematuria with other causes excluded (n = 2). Twelve patients received DAA therapy between December 2013 and September 2014. Median age was 61 years, 58% were male, and 50% had cirrhosis. Median baseline serum creatinine was 0.97 mg/dL (range 0.7-2.47). Four patients received rituximab concurrent with DAA therapy. Sustained virological response rate at 12 weeks (SVR12) was 83% overall. Patients with glomerulonephritis who achieved SVR12 experienced an improvement in serum creatinine and a reduction in proteinuria. Cryoglobulin levels decreased in 89% of patients, with median percent decreasing from 1.5% to 0.5% and completely disappearing in four of nine cases who had cryoglobulins measured after treatment. Serious adverse events were infrequent (17%). In contrast, the historical cohort treated with pegylated interferon and ribavirin experienced only 10% SVR12, with 100% experiencing at least one adverse event and 50% experiencing premature discontinuation due to adverse events.ConclusionSVR12 rates for sofosbuvir-based DAA regimens in HCV-MCS were 83%, significantly higher than historical controls treated with pegylated interferon and ribavirin; patients with glomerulonephritis experienced improvement in renal function, including those not concomitantly treated with immunosuppression.
| S-EPMC4718772 | biostudies-literature
Project description:Several direct-acting antiviral agents (DAAs) have marketing authorization in Europe and in the USA and have changed the landscape of hepatitis C treatment: each DAA has its own metabolism and drug-drug interactions (DDIs), and managing them is a challenge. To compile the pharmacokinetics and DDI data of the new DAA and to provide a guide for management of DDI. An indexed MEDLINE search was conducted using the keywords: DAA, hepatitis C, simeprevir, daclatasvir, ledipasvir, sofosbuvir, 3D regimen (paritaprevir/ritonavir, ombitasvir, dasabuvir), DDI and pharmacokinetics. Data were also collected from hepatology, and infectious disease and clinical pharmacology conferences abstracts. Food can play a role in the absorption of DAAs. Most of the interactions are linked to metabolism (cytochrome P450-3 A4 [CYP3A4]) or hepatic and/or intestinal transporters (organic anion-transporting polypeptide and P-glycoprotein [P-gp]). To a lesser extent other pathways can be involved such as breast cancer resistance protein transporter or UDP-glucuronosyltransferase metabolism. DDI are more likely to occur with 3D regimen, daclatasvir, simeprevir and ledipasvir, as they are all both substrates and inhibitors of P-gp and/or CYP3A4, than with sofosbuvir. They can increase concentrations of coadministered drugs and their concentrations may be influenced by P-gp or CYP3A4 inducers or inhibitors. Overdosage or low dosage can be encountered with potent inducers or inhibitors of CYP3A4 or drugs with a narrow therapeutic range. The key to interpret DDI data is a good understanding of the pharmacokinetic profiles of the drugs involved. Their ability to inhibit CYP450-3A4 and transporters (hepatic and/or intestinal) can have significant clinical consequences.
| S-EPMC5237698 | biostudies-other
Project description:In Pakistan, the burden of the hepatitis C virus (HCV) infection is the second highest in the world with the development of chronic hepatitis. Interferon-based combination therapy with ribavirin was the only available treatment until a few years back, with severe side-effects and high failure rates against different genotypes of HCV. Interferon-free all-oral direct-acting antiviral agents (DAAs) approved by the FDA have revolutionized the HCV therapeutic landscape due to their efficiency in targeting different genotypes in different categories of patients, including treatment naïve, treatment failure and relapsing patients, as well as patients with compensated and decompensated cirrhosis. The availability and use of these DAAs is limited in the developing world. Sofosbuvir (SOF), a uridine nucleotide analogue and inhibitor of HCV encoded NS5B polymerase, is now a widely available and in-use DAA in Pakistan; whereas daclatasvir was recently added in the list. According to the documented results, there is hope that this disease can be effectively cured in Pakistan, although a few concerns still remain. The aim of this article is to review the effectiveness of DAAs and the current status of this treatment against HCV genotype 3 infection in Pakistan; various factors associated with SVR; its limitations as an effective treatment regime; and future implications.
| S-EPMC6262417 | biostudies-other
Project description:BACKGROUND & AIMS:It is unclear whether direct-acting antiviral (DAA) treatment-induced sustained virologic response (SVR) reduces the risk of hepatocellular carcinoma (HCC) in patients with HCV infection. Therefore, in the current study, our aim was to determine the impact of DAA-induced SVR on HCC risk. METHODS:We identified 62,354 patients who initiated antiviral treatment in the Veterans Affairs (VA) national healthcare system from 1 January 1999 to 31 December 2015, including 35,871 (58%) interferon (IFN)-only regimens, 4,535 (7.2%) DAA?+?IFN regimens, and 21,948 (35%) DAA-only regimens. We retrospectively followed patients until 15 June 2017 to identify incident cases of HCC. We used Cox proportional hazards regression to determine the association between SVR and HCC risk or between type of antiviral regimen (DAA-only vs. DAA?+?IFN vs. IFN-only) and HCC risk. RESULTS:We identified 3,271 incident cases of HCC diagnosed at least 180 days after initiation of antiviral treatment during a mean follow-up of 6.1 years. The incidence of HCC was highest in patients with cirrhosis and treatment failure (3.25 per 100 patient-years), followed by cirrhosis and SVR (1.97), no cirrhosis and treatment failure (0.87), and no cirrhosis and SVR (0.24). SVR was associated with a significantly decreased risk of HCC in multivariable models irrespective of whether the antiviral treatment was DAA-only (adjusted hazard ratio [AHR] 0.29; 95% CI 0.23-0.37), DAA?+?IFN (AHR 0.48; 95% CI 0.32-0.73) or IFN-only (AHR 0.32; 95% CI 0.28-0.37). Receipt of a DAA-only or DAA?+?IFN regimen was not associated with increased HCC risk compared with receipt of an IFN-only regimen. CONCLUSIONS:DAA-induced SVR is associated with a 71% reduction in HCC risk. Treatment with DAAs is not associated with increased HCC risk compared with treatment with IFN. LAY SUMMARY:It was unclear whether direct-acting antiviral treatment-induced sustained virologic response reduces the risk of liver cancer in patients with HCV infection. We demonstrated that eradication of HCV infection with direct-acting antiviral agents reduces the risk of liver cancer by 71%.
| S-EPMC5837901 | biostudies-literature
Project description:In the last decade hepatitis C virus (HCV) kinetics has become an important clinical tool for the optimization of therapy with (pegylated)-interferon-? (IFN) and ribavirin (RBV). Mathematical models have generated important insights into HCV pathogenesis, HCV- host dynamics, and IFN and RBV's modes of action. Clinical trials with direct acting agents (DAAs) against various steps of the HCV life cycle have revealed new viral kinetic patterns that have not been observed with IFN±RBV. Very recently, studies have showed that single nucleotide polymorphisms (SNPs) in the IL28B gene region were associated with race/ethnicity and with response to IFN±RBV. Here we review our current knowledge of HCV kinetics and related mathematical models during IFN±RBV and/or DAA based therapies, HCV pathogenesis, and the role of IL28B polymorphism on early HCV kinetics. Better understanding of the mode of actions of drug(s) and viral kinetics may help to develop, in the near future, new individualized therapeutic regimens that include DAAs in combination with IFN+RBV.
| S-EPMC3237049 | biostudies-literature