Pan‐genotypic treatment regimens for hepatitis C virus: Advantages and disadvantages in high‐ and low‐income regions

During the last 5 years, the availability of direct‐acting antiviral (DAA) agents has revolutionized the treatment of hepatitis C virus (HCV). Compared with interferon/ribavirin—the previous standard of care—DAA combination regimens offer improved sustained virological response (SVR) rates, shorter treatment durations of 8‐24 weeks, convenient once‐daily single‐tablet formulations and more favourable tolerability profiles. HCV treatment is complex, and the choice of therapy must consider a complex range of factors, including baseline viral load, fibrosis stage, the HCV genotype and subgenotype, and the presence of resistance‐associated substitutions at baseline. Globally, HCV genotype 1 predominates, and there are extensive data and various treatment options available for this genotype. Genotypes 2–6 are prevalent and may even predominate in different geographical regions, reflecting diverse factors including human migration patterns and unsafe use of injection drugs and blood products. Such factors are themselves influenced by socio‐economic factors, and poor regions often have the greatest unmet need for effective HCV therapies. The latest pan‐genotypic DAA combination regimens provide the potential to eradicate HCV around the globe, regardless of genotype, hence minimizing the need for virological testing services, which often are unavailable in poorer regions. Economics inevitably remain a barrier to access, and extensive cooperation will be required between clinical organisations and pharmaceutical manufacturers to agree appropriate pricing policies, especially in poorer economic regions. This review considers key data and treatment guidelines for DAA therapies, including pan‐genotypic combination regimens, in the context of regional differences in HCV genotype and socio‐economic factors.     

A new era in the treatment of chronic hepatitis C infection

Treatment of chronic hepatitis C virus (HCV) infection has evolved over the past three decades. At the start, treatment involved interferon monotherapy followed by combination therapy using interferon and ribavirin, and subsequently evolved to pegylated interferon (Peg-IFN) and ribavirin. In genotype 1 infection, rates of sustained virological response (SVR) are approximately 45 % with Peg-IFN and ribavirin, whereas SVR rates in genotypes 2 and 3 infections are as high as 70 % to 80 %. Side effects and cost related to these drugs are important concerns, particularly in countries like India where patients have to bear their health expenses. In the recent past, there has been a significant change in course with the on-going search and the development of more effective drugs in the management of HCV infection. Telaprevir and Boceprevir are two new potent protease inhibitors (direct acting antiviral or DAA agents) which, when administered with Peg-IFN and ribavirin, have shown to result significantly higher SVR rates in phase 3 studies in patients with genotype 1 infection, both in treatment naïve patients (up to 75 %) and those with previously failed therapy. Several other new antiviral agents some in combination with Peg-IFN and ribavirin and some in combination without Peg-IFN (IFN-free regimens) are currently being tested in patients with genotype 1, 2 and 3 infections and are expected to dramatically change the armamentarium of HCV therapy in the coming years.     

Antiviral strategies in hepatitis C virus infection

Resolution of the three-dimensional structures of several hepatitis C virus (HCV) proteins, together with the development of replicative cell culture systems, has led to the identification of a number of potential targets for direct-acting antiviral (DAA) agents. Numerous families of drugs that potently inhibit the HCV lifecycle in vitro have been identified, and some of these molecules have reached early to late clinical development. Two NS3/4A protease inhibitors, telaprevir and boceprevir, were approved in Europe and the United States in 2011 in combination with pegylated interferon (IFN)-α and ribavirin for the treatment of chronic hepatitis C related to HCV genotype 1, in both treatment-na?ve and treatment-experienced patients. Sustained virological response rates in the range of 6675% and 5966% (2988% if the response to the first course of therapy is taken into account) have been achieved in these two patient populations, respectively, with treatment durations of 24 to 48 weeks. A number of other DAAs are at the clinical developmental stage in combination with pegylated IFN-α and ribavirin or with other DAAs in IFN-free regimens, with or without ribavirin. They include second-wave, first-generation, and second-generation NS3/4A protease inhibitors, nucleoside/nucleotide analogue inhibitors and non-nucleoside inhibitorsof HCVRNA-dependent RNA polymerase, inhibitors of nonstructural protein 5A (NS5A) and host-targeted compounds, such as cyclophilin inhibitors and silibinin. The proof of concept that IFN-free regimens may lead to HCV eradication has recently been brought. However, new drugs may be associated with troublesome side effects and drugdrug interactions, and the ideal IFN-free DAA combination remains to be found.     

Effect of Somatostatin on Bethanechol-Stimulated Gastric Acid Secretion and Gastric Antral Motility in Dogs with Gastric Fistula

Abstract

Objective. Sofosbuvir and simeprevir in combination with standard therapy are now available for the treatment of patients chronically infected with hepatitis C virus (HCV) genotype 1. With boceprevir and telaprevir, four treatment options are, therefore, now available to clinicians. Phase 3 studies conducted with simeprevir and sofosbuvir compared sustained virological response (SVR) data with those obtained with standard combination therapy and did not include a control arm. It is important to quantify the contribution of these molecules compared to the first direct antiviral agents available. Material and methods. For HCV genotype 1 patients, we performed a literature review and compared all SVR data from phase 3 randomized placebo-controlled trials conducted with these four molecules according to virological characteristics (genotype, viral load) and patient characteristics (IL28B polymorphism, stage of fibrosis). Results. Simeprevir and sofosbuvir provide a net gain in terms of SVR compared to boceprevir and telaprevir except in the case of telaprevir for treatment-naïve HCV genotype 1b patients. Sofosbuvir achieves higher SVR rates than simeprevir except for treatment-naïve IL28B CC patients and naïve HCV genotype 1b patient. Further, simeprevir moderately improve SVR rates compared to telaprevir in treatment-naïve patients with F3–F4 fibrosis and with HCV genotype 1a infection. Conclusion. Sofosbuvir and simeprevir greatly improve the virological response rate compared to first-generation protease inhibitors. All of these data may help in guiding the physician’s treatment decisions, based on financial constraints and patient characteristics. These data can be easily updated with future treatment and demonstrate the contribution of new treatment regimens to achieve optimal SVR rates.     

IL-28B基因多态性与丙型肝炎关系的研究进展

白细胞介素(interleukin,IL)-28B即干扰素λ3,是一类属于干扰素λ家族的新型IL,编码基因位于19号染色体上.IL-28B基因的单核苷酸多态性与基因1型HCV感染者自发清除以及聚乙二醇干扰素α和利巴韦林联合治疗抗病毒应答率之间的关系已有大量研究报道.然而,随着直接抗病毒药物的应用,IL-28B基因型对于三联疗法应答率的预测作用有待进一步研究.此外,IL-28B对基因2、3型HCV感染者抗病毒治疗应答率的影响尚不确定,对肝纤维化进展的影响也存在争议.本文就以上几方面的最新进展进行综述.     

Mixing and matching drugs: what makes sense?

The introduction and ongoing development of directly acting antiviral agents (DAAs) and drugs targeting host cell structures will change the management of patients with chronic hepatitis C virus (HCV) infection. The concomitant use of the protease inhibitors telaprevir or boceprevir with the standard of care, a combination of pegylated interferon (PegIFN) and ribavirin, will represent the new standard for the treatment of HCV genotype 1 infection. Contraindications and side effects limit the applicability of interferon-based therapies and motivate the investigation of PegIFN-sparing regimens. Different DAA combinations under investigation are reviewed in this article.     

Interferon‐free,direct‐acting antiviral therapy for chronic hepatitis C

The treatment environment for chronic hepatitis C has undergone a revolution, particularly in genotype 1. Gone are interferon‐based therapy and its associated tolerability challenges, inadequate response rates and numerous baseline factors that affect response to therapy. New and emerging treatment regimens employ all‐oral combinations of direct‐acting antiviral agents, and results of clinical trials suggest that these regimens routinely achieve cure rates >90%, even in patients who failed prior interferon‐based triple therapy. In 2015, three all‐oral FDA‐approved regiments will be available for genotype 1 (sofosbuvir /ledipasvir, sofosbuvir/simeprevir, and paritaprevir/r/ombitasvir/dasabuvir). Furthermore, new treatment combinations appear to be more tolerable and require shorter duration of therapy. We provide an overview of the classes of direct‐acting antiviral agents (DAAs), the clinical factors affecting their integration into combination therapies and recent findings from trials of such combination therapies in patients with genotype 1 HCV infection.     

Hepatitis C treatment from “response‐guided” to “resource‐guided” therapy in the transition era from interferon‐containing to interferon‐free regimens

Peginterferon/ribavirin has been the standard‐of‐care for chronic hepatitis C virus (HCV) infections: 48 weeks for genotype 1 or 4 (HCV‐1/4) and 24 weeks for HCV‐2/3. Response‐guided therapy recommended shorter 24‐ and 16‐week regimens for HCV‐1 with lower baseline viral loads (< 400 000–800 000 IU/mL) and rapid virological response (RVR, undetectable HCV RNA at week 4) and HCV‐2/3 with RVR, respectively; and extending to 72 and 48 weeks for HCV‐1 slower responders and HCV‐2 non‐RVR patients, respectively, to improve the efficacy. The progress of directly acting antivirals (DAA), moving from interferon‐containing regimens in 2011 to interferon‐free regimens in 2013, has greatly improved the treatment success. Interferon‐containing regimens include boceprevir or telaprevir or simeprevir or daclatasvir plus peginterferon/ribavirin, 24–48 weeks, for HCV‐1 or 4. However, adding these DAA has no benefit for HCV‐1 with lower baseline viral loads/RVR. Instead, 12‐week sofosbuvir plus peginterferon/ribavirin attained sustained virological response rates of > 90% for HCV‐1/3–6. Interferon‐free regimens include two main categories: NS5B nucleotide inhibitor (sofosbuvir)‐based regimens and NS3/4A inhibitor/NS5A inhibitor‐based regimens (daclatasvir/asunaprevir, paritaprevir/r/ombitasvir/dasabuvir and grazoprevir/elbasvir). About 8–24 weeks interferon‐free regimens could achieve sustained virological response rates of 82–99% for corresponding HCV genotypes. Although the newly DAA interferon‐free regimens have high efficacy and safety, the huge budget impact increases the treatment barriers. The current recommendation should, therefore, base on the availability, indication, and cost‐effectiveness in the transition era of DAA. Based on the concept of “resource‐guided therapy,” peginterferon/ribavirin might be applied for easy‐to‐treat interferon‐eligible patients in resource‐constrained areas. Prioritizing patients for interferon‐free regimens according to “time‐degenerative factors” (age and fibrosis) is justified before the regimens becoming available and affordable.     

Sofosbuvir plus simeprevir for the treatment of HCV genotype 4 patients with advanced fibrosis or compensated cirrhosis is highly efficacious in real life

Chronic hepatitis C virus (HCV) infection is a major cause of chronic liver disease and liver‐related death. Recently, multiple regimens of different direct‐acting antiviral agents (DAAs) have been registered. Although treatment with sofosbuvir (SOF) and simeprevir (SMV) is registered for the treatment of genotype 4 patients in some countries, data on efficacy of this combination are lacking. We aimed to assess the efficacy of SOF and SMV with or without RBV during 12 weeks in a real‐life cohort of genotype 4 HCV patients. A retrospective multicentre observational study was conducted in 4 hospitals in Amsterdam, the Netherlands, including patients with advanced liver fibrosis or liver cirrhosis treated with SOF plus SMV with or without RBV during 12 weeks for a genotype 4 chronic HCV infection from 1 January 2015 to 1 August 2015. Sustained viral response (SVR) was established at week 12 after end of treatment. A total of 53 patients with genotype 4 HCV infection, treatment naïve and experienced, were included. SVR was achieved in 49 of 53 patients (92%). The four failures all had a virological relapse and did not receive ribavirin. Three were nonresponder to earlier interferon‐based treatment, and one was treatment naive. In this real‐life cohort of patients with HCV genotype 4 infection and advanced liver fibrosis/cirrhosis, we show that treatment with SOF and SMV is effective. The addition of RBV could be considered in treatment‐experienced patients as recommended in guidelines.     

Protease inhibitors for the treatment of chronic hepatitis C genotype-1 infection: the new standard of care

For the past decade, the standard treatment for chronic hepatitis C infection has been pegylated-interferon plus ribavirin. With US Food and Drug Administration approval of boceprevir and telaprevir-two protease inhibitors-the standard-of-care treatment for genotype-1 infection, the main genotype worldwide, is now peginterferon plus ribavirin and a protease inhibitor. Rates of sustained virological response or cure with triple combination treatment have improved substantially, both in patients who have had previous treatment and in those who have not. Improvements have been most substantial in populations regarded as difficult to treat, such as individuals with cirrhosis. However, despite improved response rates, protease inhibitors have incremental toxic effects, high costs, increased pill burden, and many drug interactions. Moreover, because new antiviral drugs directly inhibit hepatitis C virus, viral resistance has become an important issue, essentially precluding use of protease inhibitor monotherapy, and potentially restricting future treatment options for patients who consequently do not achieve sustained virological response. Protease inhibitors are the first of many antiviral medications that will probably be combined in future interferon-free regimens.     

Antiviral treatment of hepatitis C virus infection and factors affecting efficacy

Hepatitis C virus(HCV)infection is the leading cause of chronic liver-related diseases,including cirrhosis,liver failure,and hepatocellular carcinoma.Currently,no effective vaccine is available for HCV infection.Polyethylene glycol interferon-α(PegIFN-α)in combination with ribavirin(RBV)is the standard of care(SOC)for chronic hepatitis C.However,the efficacy of PegIFN-αand RBV combination therapy is less than 50%for genotype 1HCV,which is the dominant virus in humans.In addition,IFN and RBV have several severe side effects.Therefore,strategies to improve sustained virological response(SVR)rates have been an important focus for clinical physicians.The serine protease inhibitors telaprevir and boceprevir were approved by the United States Food and Drug Administration in 2011.The addition of HCV protease inhibitors to the SOC has significantly improved the efficacy of treatments for HCV infection.Several direct-acting antiviral drugs currently in late-stage clinical trials,both with and without pegIFN and RBV,have several advantages over the previous SOC,including higher specificity and efficacy,fewer side effects,and the ability to be administered orally,and might be optimal regimens in the future.Factors affecting the efficacy of anti-HCV treatments based on IFN-αinclude the HCV genotype,baseline viral load,virological response during treatment,host IL28B gene polymorphisms and hepatic steatosis.However,determining the effect of the above factors on DAA therapy is necessary.In this review,we summarize the development of antiHCV agents and assess the main factors affecting the efficacy of antiviral treatments.     

New direct-acting antiviral agents for the treatment of hepatitis C virus infection and perspectives

Until recently, the standard of care (SOC) for patients with chronic hepatitis C virus (HCV) infection has consisted of a combination of pegylated interferon-α [corrected] plus ribavirin, administered for 24- to 48-weeks depending on the HCV genotype. The sustained virologic response rate for this SOC has been only about 50% in patients infected with genotype 1 HCV, the most prevalent genotype in Europe and North America. HCV therapy has been revolutionised recently by the approval of two direct-acting antiviral agents (DAA) against the NS3/4A serine protease for use in genotype 1 HCV, the ketoamide inhibitors boceprevir and telaprevir. The novel SOC marks the beginning of an extraordinary new era in HCV therapy. We review this new SOC with an emphasis on practical issues related to protease inhibitors, e.g. prescribing guidelines, futility rules and management of adverse events. We also give a perspective on what to expect in the coming years. Newer DAA with simplified dosing regimens and/or minimal toxicity which, when used in combination, will lead to viral eradication in most if not all CHC patients who undergo treatment. The novel agents in clinical development are paving the way for future interferon-sparing regimens.     

Recent successes and noteworthy future prospects in the treatment of chronic hepatitis C

Within the last year, the landscape of therapy for genotype 1 chronic hepatitis C virus (HCV) has changed dramatically as 2 much-anticipated protease inhibitors became available for use. These agents, telaprevir and boceprevir, when used in combination with pegylated interferon and ribavirin, offer patients an improved chance of cure and the opportunity for a shorter duration of therapy. Although these medications represent a significant achievement in the battle against HCV, they do not represent the final phase in the evolution of HCV therapy. Many other direct-acting antiviral agents representing several classes, as well as agents that act via host-mediated pathways, are in development. Recent proof of concept studies demonstrating the capacity to eradicate HCV without interferon signal the potential for yet another quantum leap in the field.     

Ribavirin mode of action in chronic hepatitis C: from clinical use back to molecular mechanisms

Ribavirin is an old broad‐spectrum antiviral that is highly effective when used in combination with interferon‐α and also as part of triple therapies containing new inhibitors of the hepatitis C virus (HCV) non‐structural (NS)3/4 protease or HCV NS5B polymerase for the treatment of patients with chronic hepatitis C. However, the molecular mechanisms by which ribavirin enhances early and sustained virological response rates during interferon‐based antiviral HCV therapy are still unknown. Several mechanisms including (i) immunomodulatory properties, (ii) inhibition of the inosine monophosphate dehydrogenase, (iii) direct inhibition of the HCV‐encoded NS5B RNA polymerase, (iv) induction of lethal mutagenesis and (v) modulation of interferon‐stimulated gene expression are currently proposed. Here, we discuss recent advances from in vitro data and their importance for the situation in patients with chronic hepatitis C. Furthermore, theoretical aspects from mathematical modelling of ribavirin action in chronic hepatitis C are reviewed.     

Hepatitis C drugs: The end of the pegylated interferon era and the emergence of all-oral,interferon-free antiviral regimens: A concise review

Between 2001 and 2011, the standard of care for chronic hepatitis C virus (HCV) infection was a combination of pegylated interferon (PEGIFN) and ribavirin (RBV). In May 2011, boceprevir and telaprevir, two first-generation NS3/4A protease inhibitors, were approved in combination with PEG-IFN and RBV for 24 to 48 weeks in hepatitis C virus genotype 1 infections. In December 2013, simeprevir, a second-generation NS3/4A protease inhibitor, was approved for use with PEG-IFN and RBV for 12 weeks in genotype 1, while sofosbuvir, a NS5B nucleotide polymerase inhibitor, was approved for use with PEG-IFN and RBV for 12 weeks in genotypes 1 and 4, as well as with RBV alone for 12 weeks in genotype 2 and for 24 weeks in genotype 3. Sofosbuvir combined with simeprevir or an NS5A replication complex inhibitor (ledipasvir or daclatasvir) with or without RBV for 12 weeks in genotype 1 resulted in a sustained virological response >90%, irrespective of previous treatment history or presence of cirrhosis. Similarly impressive sustained virological response rates have been shown with ABT-450/r (ritonavir-boosted NS3/4A protease inhibitor)-based regimens in combination with other direct-acting antiviral agent(s) with or without RBV for 12 weeks in genotype 1. The optimal all-oral interferon-free antiviral regimen likely entails a combination of an NS5B nucleotide polymerase inhibitor with either a second-generation NS3/4A protease inhibitor or an NS5A replication complex inhibitor with or without RBV. Further research is needed to determine the role of resistance testing, clarify the optimal follow-up duration post-treatment, and evaluate the antiviral efficacy and safety in difficult-to-cure patient populations.     

Impact of new treatment options for hepatitis c virus infection in liver transplantation

Liver transplant candidates and recipients with hepatitis C virus(HCV)-related liver disease greatly benefit from an effective antiviral therapy. The achievement of a sustained virological response before transplantation can prevent the recurrence of post-transplant HCV disease that occurs universally and correlates with enhanced progression to graft cirrhosis. Previous standard-of-care regimens(e.g.,pegylated-interferon plus ribavirin with or without first generation protease inhibitors,boceprevir and telaprevir) displayed suboptimal results and poor tolerance in liver transplant recipients. A new class of potent direct-acting antiviral agents(DAA) characterized by all-oral regimens with minimal side effects has been approved and included in the recent guidelines for the treatment of liver transplant recipients with recurrent HCV disease. Association of sofosbuvir with ribavirin and/or ledipasvir is recommended in liver transplant recipients and patients with decompensated cirrhosis. Other regimens include simeprevir,daclatasvir,and combination of other DAA. Possible interactions should be monitored,especially in coinfected human immunodeficiency virus/HCV patients receiving antiretrovirals.     

Antiviral therapies for chronic hepatitis C virus infection with cirrhosis

Patients who are infected with hepatitis C virus(HCV) and also have advanced fibrosis or cirrhosis have beenrecognized as "difficult-to-treat" patients during an era when peginterferon and ribavirin combination therapy is the standard of care. Recent guidelines have clearly stated that treatment should be prioritized in this population to prevent complications such as decompensation and hepatocellular carcinoma. Recent advances in the treatment of chronic hepatitis C have been achieved through the development of direct-acting antiviral agents(DAAs). Boceprevir and telaprevir are first-generation DAAs that inhibit the HCV NS3/4A protease. Boceprevir or telaprevir, in combination with peginterferon and ribavirin, improved the sustained virological response rates compared with peginterferon and ribavirin alone and were tolerated in patients with HCV genotype 1 infection without cirrhosis or compensated cirrhosis. However, the efficacy is lower especially in prior non-responders with or without cirrhosis. Furthermore, a high incidence of adverse events was observed in patients with advanced liver disease, including cirrhosis, in real-life settings. Current guidelines in the United States and in some European countries no longer recommend these regimens for the treatment of HCV. Next-generation DAAs include second-generation HCV NS3/4A protease inhibitors, HCV NS5 A inhibitors and HCV NS5 B inhibitors, which have a high efficacy and a lower toxicity. These drugs are used in interferon-free or in interferon-based regimens with or without ribavirin in combination with different classes of DAAs. Interferon-based regimens, such as simeprevir in combination with peginterferon and ribavirin, are well tolerated and are highly effective especially in treatmentnave patients and in patients who received treatment but who relapsed. The efficacy is less pronounced in nullresponders and in patients with cirrhosis. Interferonfree regimens in combination with ribavirin and/or two or more DAAs could be used for treatment-nave, treatment-experienced and even for interferon-ineligible or interferon-intolerant patients. Some clinical trials have demonstrated promising results, and have shown that the efficacy and safety were not different between patients with and without cirrhosis. There are also promising regimens for genotypes other than genotype 1. Interferonis contraindicated in patients with decompensated cirrhosis, and further studies are needed to establish the optimal treatment regimen for this population. In the future, interferon-free and ribavirin-free regimens with high efficacy and improved safety are expected for HCVinfected patients with advanced liver diseases.     

CIHR Canadian HIV Trials Network Co-Infection and Concurrent Diseases Core: Updated Canadian guidelines for the treatment of hepatitis C infection in HIV-hepatitis C coinfected adults

BACKGROUND:Hepatitis C virus (HCV) coinfection occurs in 20% to 30% of Canadians living with HIV and is responsible for a heavy burden of morbidity and mortality. Management of HIV-HCV coinfection is more complex due to the accelerated progression of liver disease, the timing and nature of antiretroviral and HCV therapy, mental health and addictions management, socioeconomic obstacles and drug-drug interactions between new HCV direct-acting antiviral therapies and antiretroviral regimens.OBJECTIVE:To update national standards for the management of HCV-HIV coinfected adults in the Canadian context.METHODS:A standing working group with specific clinical expertise in HIV-HCV coinfection was convened by The Canadian Institute of Health Research HIV Trials Network to review recently published data regarding HCV antiviral treatments and to update the Canadian HIV-HCV coinfection guidelines.RESULTS:Recent data suggest that the gap in sustained virological response rates between HCV monoinfection and HIV-HCV coinfection has been eliminated with newer HCV antiviral regimens. All HIV-HCV coinfected individuals should be assessed for HCV therapy. First-line treatment for genotypes 1 through 6 includes pegylated interferon and weight-based ribavirin dosing plus the nucleotide sofosbuvir for 12 weeks. Sofosbuvir in combination with the protease inhibitor simeprevir is another first-line consideration for genotype 1 infection. Sofosbuvir with ribavirin for 12 weeks (genotype 2) and 24 weeks (genotype 3) is also recommended as first-line treatment.DISCUSSION:Recommendations may not supersede individual clinical judgement.     

Hepatitis C: viral and host factors associated with non‐response to pegylated interferon plus ribavirin

Treatment for chronic hepatitis C virus (HCV) infection has evolved considerably in the last years. The standard of care (SOC) for HCV infection consists in the combination of pegylated interferon (PEG‐IFN) plus ribavirin. However, it only induces a sustained virological response (SVR) in half of genotype 1‐infected patients. Several viral and host factors have been associated with non‐response: steatosis, obesity, insulin resistance, age, male sex, ethnicity and genotypes. Many studies have demonstrated that in non‐responders, some interferon‐stimulated genes were upregulated before treatment. Those findings associated to clinical, biochemical and histological data may help detect responders before starting any treatment. This is a very important issue because the standard treatment is physically and economically demanding. The future of HCV treatment would probably consist in the addition of specifically targeted antiviral therapy for HCV such as protease and/or polymerase inhibitors to the SOC. In genotype 1 patients, very promising results have been reported when the protease inhibitor telaprevir or boceprevir is added to the SOC. It increases the SVR rates from approximately 50% (PEG‐IFN plus ribavirin) to 70% (for patients treated with a combination of PEG‐IFN plus ribavirin plus telaprevir). Different elements are associated with non‐response: (i) viral factors, (ii) host factors and (iii) molecular mechanisms induced by HCV proteins to inhibit the IFN signalling pathway. The goal of this review is to present the mechanisms of non‐response, to overcome it and to identify factors that can help to predict the response to anti‐HCV therapy.     

The future for the treatment of genotype 4 chronic hepatitis C

Hepatitis C virus genotype 4 (HCV-4) is the most common type of hepatitis C virus (HCV) in the Middle East and Africa, in particular Egypt. Since the development of new protease inhibitors, the response of HCV-4 to the standard regimen of treatment (pegylated interferon/ribavirin) lags behind other genotypes and has become the most resistant type to treat. The development of therapeutic strategies for all patients with HCV-4 whether they are na?ve, have experienced a virological breakthrough, are relapsers or non-responders is still a considerable challenge. New types of interferon (Consensus Interferon, Y-shaped, Albinterferon...) and new direct action antiviral drugs (Nitazoxanide, Vit.D, other) may improve the treatment of patients with HCV-4. The IL28B CC polymorphism may be associated with sustained virological response.