Sofosbuvir and ABT-450: Terminator of hepatitis C virus?

Combination therapy with peginterferon (pegIFN)-α and ribavirin (RBV) has been the standard of care (SOC) for chronic hepatitis C. Unfortunately, not all patients can achieve a sustained virologic response (SVR) with this regimen. SVR rates are approximately 80% in patients with hepatitis C virus (HCV) genotype 2, 3, 5 and 6 and 40%-50% in patients with genotype 1 and 4. Therefore, strategies to improve SVR rates have been an important issue for clinical physicians. Several direct acting antiviral agents (DAAs) have significantly higher SVR rates when combined with pegIFN-α and RBV than pegIFN-α and RBV alone. Treatments containing DAAs have several advantages over the previous SOC, including higher specificity and efficacy, shorter treatment durations, fewer side effects, and oral administration. Based on these advantages, treatment with pegIFN-α and RBV plus telaprevir or boceprevir has become the current SOC for patients with genotype 1 HCV infection. However, many patients are either not eligible for therapy or decline treatment due to coexisting relative or absolute contraindications as well as an inability to tolerate the hematological side effects and adverse events caused by the new SOC. These factors have contributed to the advent of pegIFN-α-free regimens. The newest therapeutic regimens containing sofosbuvir and ABT-450 have shown promising results. In this review, we summarize the development of anti-HCV agents and the clinical efficacy of sofosbuvir and ABT-450-based therapies as well as the potential for future HCV studies.     

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.     

Current and future treatment options for HCV

Aim of antiviral therapy of patients with chronic hepatitis C is the sustained elimination of the hepatitis C virus (HCV). The standard of care (SOC) is peginterferon alfa-2a/-2b with ribavirin for 48 weeks or 24 weeks in patients infected with HCV genotype 1 or 2/3, respectively. Overall, approximately half of the patients can be cured by SOC. Based on baseline viral load and the speed of virologic response during treatment, individualization of treatment duration is possible. However, this approach is not sufficient to substantially improve the sustained virologic response (SVR) rates. This goal can be achieved with new HCV specific inhibitors against the NS3/4A polymerase and the NS5B polymerase. Recent trials reported SVR rates in the order of 67-69% and 67-75% for the combination of SOC with the protease inhibitors telaprevir and boceprevir, respectively, in patients with HCV genotype 1 infection. Several new HCV specific inhibitors such as protease inhibitors, nucleoside and non-nucleoside polymerase inhibitors as well as non HCV specific compounds with anti-HCV activity such as cyclophilin inhibitors, silibinin, and nitazoxanide are currently in clinical evaluation. The review describes recent developments and discusses limitations posed by resistance development and drug toxicity.     

Serum Lipoprotein Profiles and Response to Pegylated Interferon Plus Ribavirin Combination Therapy in Patients With Chronic HCV Genotype 1b Infection

Background

Abnormal serum lipid profiles have been noted in patients with chronic hepatitis C virus (HCV) infection. Moreover, many reports suggest that serum lipoprotein profiles are more profoundly distorted in patients with HCV G1b infection who have an unfavorable response to pegylated interferon (peg-IFN) plus ribavirin (RBV) combination therapy. However, after the discovery of single nucleotide polymorphisms near the IL28B gene (rs8099917 and rs12979860) as potent predictive factors affecting the response to peg-IFN plus RBV, lipid factors are thought to be confounding factors.

Objectives

To re-examine the significance of lipoprotein profiles on virological response to peg-IFN plus RBV combination therapy in patients with chronic HCV G1b infection, we examined cholesterol and triglyceride concentrations in each lipoprotein fraction separated by high performance liquid chromatography.

Patients and Methods

Lipoprotein profiles were examined using fasting sera from 108 patients infected with HCV G1b who had chronic hepatitis, as determined by liver biopsy. Results of lipoprotein profiles and clinical data, including IL28B genotype and amino acid substitution at aa70 of HCV G1b, were compared between patients with a sustained virological response (SVR) and non-SVR or a non-virological response (NVR) and virological responses other than NVR (non-NVR). In addition, significant predictive factors independently associated with virological response to peg-IFNα-2b plus RBV were determined by logistic regression analysis.

Results

An increased ratio of cholesterol/triglyceride in very low-density lipoprotein (odds ratio (OR) 3.03; 95% confidence interval (CI) 1.01-9.44) along with a major genotype of rs8099917 (OR 9.09; 95% CI 2.94-33.33), were independent predictive factors for SVR. In contrast, lipid factors were not elucidated as independent predictive factors for NVR.

Conclusions

Examination of the fasting lipid profile has clinical importance in predicting the efficacy of peg-IFN-α-2b plus RBV combination therapy for patients with HCV G1b even after the discovery of the IL28 genotype as a potent predictive factor.     

Dual therapy with the nonstructural protein 5A inhibitor, daclatasvir, and the nonstructural protein 3 protease inhibitor, asunaprevir, in hepatitis C virus genotype 1b-infected null responders

Patients with chronic hepatitis C virus (HCV) infection and previous null response to pegylated interferon (Peg-IFN) and ribavirin (RBV) have limited therapeutic options. HCV genotype 1 is the most common worldwide and the most difficult to treat; genotype 1b is the most common subtype of genotype 1 outside North America. The enhanced antiviral activity achieved by combining two direct-acting antiviral (DAA) agents may improve clinical outcomes. This open-label, phase IIa study included 10 patients with chronic HCV genotype 1b infection and previous null response (<2 log(10) reduction in HCV RNA after 12 weeks) to Peg-IFN and RBV. Patients received dual DAA treatment for 24 weeks with the nonstructural protein 5A replication complex inhibitor, daclatasvir (60 mg once-daily), and the nonstructural protein 3 protease inhibitor, asunaprevir (initially 600 mg twice-daily, then subsequently reduced to 200 mg twice-daily). The primary efficacy endpoint was the proportion of patients with sustained virologic response (SVR) at 12 weeks post-treatment (SVR(12) ). Nine patients completed 24 weeks of treatment; 1 patient discontinued treatment after 2 weeks. In the 9 patients who completed the full course of treatment, HCV RNA was undetectable at week 8 and remained undetectable through the end of treatment; all 9 patients achieved SVR(12) and SVR(24) . HCV RNA also remained undetectable post-treatment in the patient who discontinued after 2 weeks. There was no viral breakthrough. Diarrhea and headache, generally mild, were the most common adverse events; transaminase elevations were reported in 3 patients, but did not result in discontinuation. CONCLUSIONS: Dual therapy with daclatasvir and asunaprevir, without Peg-IFN and RBV, can achieve high SVR rates in difficult-to-treat patients with HCV genotype 1b infection and previous null response to Peg-IFN and RBV.     

Interferon-Free Hepatitis C Treatment before and after Liver Transplantation: The Role of HCV Drug Resistance

Hepatitis C virus (HCV) infection is one of the leading causes of end-stage liver disease and the main indication for liver transplantation (LT) in most countries. All patients who undergo LT with detectable serum HCV RNA experience graft reinfection progressing to cirrhosis within five years in 20% to 30% of them. Obtaining a sustained virological response (SVR) greatly improves overall and graft survival. Until 2011, standard antiviral therapy using PEGylated interferon (PEG-IFN) and ribavirin (RBV) was the only effective therapy, with an SVR rate around 30% in this setting. For patients infected with genotype 1, first generation NS3/4A protease inhibitors (PIs), boceprevir (BOC) or telaprevir (TVR), associated with PEG-IFN and RBV for 48 weeks have increased the SVR rates to 60% in non-transplant patients. However, tolerability and drug-drug interactions with calcineurin inhibitors (CNI) are both limiting factors of their use in the liver transplant setting. Over recent years, the efficacy of antiviral C therapy has improved dramatically using new direct-acting antiviral (DAA) agents without PEG-IFN and/or RBV, leading to SVR rates over 90% in non-transplant patients. Results available for transplant patients showed a better efficacy and tolerability and less drug-drug interactions than with first wave PIs. However, some infrequent cases of viral resistance have been reported using PIs or NS5A inhibitors pre- or post-LT that can lead to difficulties in the management of these patients.     

Ribavirin induced hemolysis: A novel mechanism of action against chronic hepatitis C virus infection

Hepatitis C virus(HCV)is not usually cleared by our immune system,leading to the development of chronic hepatitis C infection.Chronic HCV induces the production of various cytokines,predominantly by Kupffer cells(KCs),and creates a pro-inflammatory state in the liver.The chronic dysregulated production of interferon(IFN)and other cytokines by KCs also promotes innate immune tolerance.Ribavirin(RBV)monotherapy has been shown to decrease inflammation in liver of patients with chronic hepatitis C.Sustained virological response(SVR)is significantly higher when IFN is combined with RBV in chronic HCV(c HCV)infection.However,the mechanism of their synergy remains unclear.Previous theories have attempted to explain the anti-HCV effect based on direct action of RBV alone on the virus or on the immune system;however,these theories have serious shortcomings.We propose that hemolysis,which universally occurs with RBV therapy and which is considered a limiting side effect,is precisely the mechanism by which the anti-HCV effect is exerted.Passive hemolysis results in anti-inflammatory/antiviral actions within the liver that disrupt the innate immune tolerance,leading to the synergy ofRBV with IFN-α.Ribavirin-induced hemolysis floods the hepatocytes and KCs with heme,which is metabolized and detoxified by heme oxygenase-1(HMOX1)to carbon monoxide(CO),biliverdin and free iron(which induces ferritin).These metabolites of heme possess anti-inflammatory and antioxidant properties.Thus,HMOX1 plays an extremely important anti-oxidant,anti-inflammatory and cytoprotective role,particularly in KCs and hepatocytes.HMOX1 has been noted to have anti-viral effects in hepatitis C infected cell lines.Additionally,it has been shown to enhance the response to IFN-αby restoring interferon-stimulated genes(ISGs).This mechanism can be clinically corroborated by the following observations that have been found in patients undergoing RBV/IFN combination therapy for c HCV:(1)SVR rates are higher in patients who develop anemia;(2)once anemia(due to hemolysis)occurs,the SVR rate does not depend on the treatment utilized to manage anemia;and(3)ribavirin analogs,such as taribavirin and levovirin,which increase intrahepatic ribavirin levels and which produce lesser hemolysis,are inferior to ribavirin for treating c HCV.This mechanism can also explain the observed RBV synergy with direct antiviral agents.This hypothesis is testable and may lead to newer and safer medications for treating c HCV infection.     

Emerging Therapies for Hepatitis C

The combination of pegylated interferon (PEG-IFN) and ribavirin (RBV), the current therapy for hepatitis C virus (HCV) infection, has saved the lives of many HCV-infected patients. Direct-acting antivirals (DAAs) target several sites of HCV nonstructural proteins, resulting in the cessation of viral replication. The first NS3/4A protease inhibitors consisted of boceprevir and telaprevir, which have shown superior efficacy against genotype 1 HCV infection when combined with PEG-IFN/RBV compared with the standard therapy in both treatment-naive and -experienced patients. Simeprevir, faldaprevir, and asunaprevir are second-wave, first-generation NS3/4A inhibitors that have already been or will soon be approved. Second-generation protease inhibitors are in clinical trials. Daclatasvir is the first approved DAA belonging to the class of NS5A replication complex inhibitors. The potency of daclatasvir is very high, and this drug is an important and essential component of combination regimens for all genotypes. Sofosbuvir, the first approved NS5B polymerase inhibitor, is characterized by high potency and genetic barriers to resistance. Sofosbuvir combined with RBV achieved an interferon-free regimen in genotype 2 or 3 patients with a reduced treatment duration. It can also be used in combination with PEG-IFN/RBV in genotype 1 patients for 12 weeks. DAAs have provided new hope for curing HCV infections with a short treatment duration and acceptable adverse events.     

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.     

The therapeutic approaches for hepatitis C virus: protease inhibitors and polymerase inhibitors

The current standard of care for hepatitis C infection is peginterferon/ribavirin (PegIFN/RBV). We are entering the era where direct-acting antiviral agents (DAAs) will be added to PegIFN/RBV, leading to higher sustained response rates in genotype 1 infected individuals. Currently DAAs are directed toward specific proteins involved in hepatitis C replication with NS3/NS4A protease inhibitors furthest in development. Telaprevir and boceprevir are both NS3/NS4a inhibitors that significantly improve sustained response when added to PegIFN and RBV. The hepatitis C virus (HCV) polymerase inhibitors are another promising DAA class. These molecules are divided into nucleoside/nucleotide polymerase inhibitors and nonnucleotide/nucleoside polymerase inhibitors. Nucleoside/nucleotide polymerase inhibitors have a high barrier to resistance and appear to be effective across a broad range of genotypes. Nonnucleoside polymerase inhibitors have a lower barrier of resistance and appear to be genotype specific. Preliminary data with these compounds are also promising. A third class, NS5A inhibitors, has also shown potent HCV RNA suppression in preliminary studies as monotherapy and with PegIFN and RBV. Combinations of these agents are also entering clinical trials and indeed a preliminary report has demonstrated that the combination of an NS3/4A protease inhibitor and NS5B polymerase inhibitor can effectively suppress virus in genotype 1 individuals. Future studies will concentrate on combinations of direct-acting antiviral agents without and with PegIFN and RBV. Clinicians will need to be familiar with managing side effects as well as resistance as we enter this new era.     

Antiviral therapy for hepatitis C in the setting of liver transplantation

Opinion statement Hepatitis C viremia after liver transplantation for hepatitis C virus (HCV) liver disease is universal. Progressive HCV disease after transplantation is the leading cause of death, graft failure, and retransplantation. Whether to treat, with which agents, and timing of therapy are unanswered questions. Timing options include pretransplantation, prophylactic, posttransplantation preemptive, and post-transplantation recurrence-based therapy. The latter is most commonly utilized. There are little data for each of these, much less comparisons. Pegylated interferon-a has supplanted standard interferon-a due to increased efficacy and is generally used in combination with ribavirin (RBV). Efficacy is less than in nontransplant settings due to immunosuppression, an increased prevalence of genotype 1 HCV, patient comorbidities, and decreased functional status. Administration of HCV therapy to cirrhotic patients prior to transplantation may eradicate or suppress HCV and prevent or reduce severity of recurrence. Sustained virological response (SVR) as high as 50% was attained in genotypes 2 or 3 HCV. Comparison of preemptive and histology-based post-transplantation HCV therapy should be done, and more data will be available on pretransplantation therapy. Post-transplant patients are less tolerant of therapy, particularly RBV. SVR, the primary goal of therapy, likely halts disease progression, but only 20% to 30% of treated patients achieve SVR. Preemptive therapy early after transplantation may have advantages due to the potential to delay or blunt severity of graft infection and recurrent hepatitis. In posttransplant therapy, RBV toxicity is attenuated in relation to decreased renal function, and side effects of interferon are more prominent. An ongoing trial will assess preemptive therapy with treatment after histologic recurrence. Novel anti-HCV therapies such as protease and polymerase inhibitors are emerging. These must be tested with urgency in the transplant setting. Retransplantation for progressive HCV disease is more controversial due to poor outcomes, graft shortage, and disease recurrence.     

Triple therapy with boceprevir or telaprevir for prior HCV non-responders

Approximately 170 million people are infected with hepatitis C virus (HCV) worldwide. Sustained virological response (SVR) is equivalent to viral eradication and associated with a reduction in the risk of cirrhosis and hepatocellular carcinoma. The treatment for genotype 1 HCV chronic infection is the addition of a protease inhibitor (telaprevir or boceprevir) to the pegylated-interferon (PEG-IFN) plus ribavirin (RBV) regimen. Treatment of genotype 1 naïve chronic hepatitis C with PEG-IFN and ribavirin (RBV) for 48 weeks results in SVR in approximately 40% of patients. Retreatment of previous relapsers to PEG-IFN/RBV therapy with triple therapy, a protease inhibitor (telaprevir or boceprevir), plus PEG-IFN and RBV results in SVR in more than 70% of cases. However, retreatment of previous non-responders to PEG-IFN/RBV therapy with these triple therapies, results in SVR in less than 30% of cases. The aim of this review is to summarize results obtained with Boceprevir or Telaprevir triple therapy for prior HCV experienced patients (non-responders and relapsers).     

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.     

Real-World Data from Turkey: Is Sofosbuvir/Ledipasvir With or Without Ribavirin Treatment for Chronic Hepatitis C Really Effective?

Background: In this study, we aimed to investigate the efficacy and safety of sofosbuvir-based therapies in the treatment of chronic hepatitis C in real-world clinical practice.Methods: Data from patients with chronic hepatitis C treated with SOF/LDV ± RBV or SOF/RBV in 31 centers across Turkey between April 1, 2017, and August 31, 2018, were recorded in a nationwide database among infectious disease specialists. Demographics, clinical, and virological outcomes were analyzed.Results: A total of 552 patients were included in the study. The mean age of the patients was 51.28 ± 14.2, and 293 (55.8%) were female. The majority had HCV genotype 1b infection (65%), 75.04% of the patients underwent treatment, and non-cirrhosis was present at baseline in 381 patients (72.6%). SOF/LDV ± RBV treatment was given to 477 patients and 48 patients received SOF/RBV according to HCV genotype. The total SVR12 rate was 99% in all patients. Five patients experienced disease relapse during the study and all of them were genotype 2. In patients infected with HCV GT2, SVR12 was 77.3%. SVR was 100% in all patients infected with other HCV genotypes. All treatments were well tolerated by patients without causing severe adverse events. Side effects and side effects-associated treatment discontinuation rates were 28.2% and 0.4%, respectively. Weakness (13.7%) was the common side effect.Conclusion: The present real-world data of 525 patients with HCV genotypes 1, 1a, 1b, 3, 4, and 5 who underwent SOF/LDV ± RBV treatment in Turkey demonstrated a high efficacy and safety profile. HCV GT2 patients should be treated with more efficacious treatment.     

Current progress in the treatment of chronic hepatitis C

Over the last decade, the standard of care for the treatment of chronic hepatitis C has been the combination of pegylated-interferon-alfa (PEG-IFN) and ribavirin (RBV) which results in sustained virological response (SVR) rates of 75%-85% in patients with genotypes 2 or 3 but only of 40%-50% in patients with genotype 1. Currently, there are rapid and continuous developments of numerous new agents against hepatitis C virus (HCV), which are the focus of this review. Boceprevir and telaprevir, two first-generation NS3/4A HCV protease inhibitors, have been recently licensed in several countries around the world to be used in combination with PEG-IFN and RBV for the treatment of genotype 1 patients. Boceprevir or telaprevir based triple regimens, compared with the PEG-IFN/RBV combination, improve the SVR rates by 25%-31% in treatment-naïve genotype 1 patients, by 40%-64% in prior relapsers, by 33%-45% in prior partial responders and by 24%-28% in prior null responders. At the same time, the application of response-guided treatment algorithms according to the on-treatment virological response results in shortening of the total therapy duration to only 24 wk in 45%-55% of treatment-naïve patients. There are, however, several challenges with the use of the new triple combinations in genotype 1 patients, such as the need for immediate results of HCV RNA testing using sensitive quantitative assays, new and more frequent adverse events (anemia and dysgeusia for boceprevir; pruritus, rash and anemia for telaprevir), new drug interactions and increasing difficulties in compliance. Moreover, the SVR rates are still poor in very difficult to treat subgroups of genotype 1 patients, such as null responders with cirrhosis, while there is no benefit for patients who cannot tolerate PEG-IFN/RBV or who are infected with non-1 HCV genotype. Many newer anti-HCV agents of different classes and numerous combinations are currently under evaluation with encouraging results. Preliminary data suggest that the treatment of chronic HCV patients with well tolerated combinations of oral agents without PEG-IFN is feasible and may lead to a universal HCV cure over the next 5-10 years.     

Two patients treated with pegylated interferon/ribavirin/telaprevir triple therapy for recurrent hepatitis C after living donor liver transplantation

It is difficult to use protease inhibitors in patients with recurrent hepatitis C virus (HCV) infection after liver transplantation (LT) due to interaction with immunosuppressive drugs. We report our experience with two patients treated with telaprevir (TVR) combined with pegylated interferon/ribavirin (PEG IFN/RBV) for recurrent HCV genotype 1 infection after LT. The first was a 63‐year‐old man with HCV‐related liver cirrhosis, who failed to respond to IFN‐β plus RBV after LT. Treatment was switched to PEG IFN‐α‐2b plus RBV and TVR was started. The donor had TT genotype of interleukin (IL)‐28 single nucleotide polymorphisms (SNP) (rs8099917). The recipient had TT genotype of IL‐28 SNP (rs8099917). Completion of 12‐week triple therapy was followed by PEG IFN‐α‐2b plus RBV for 36 weeks. Finally, he had sustained viral response. The second was a 70‐year‐old woman with HCV‐related liver cirrhosis and hepatocellular carcinoma. She failed to respond to PEG IFN‐α‐2b plus RBV after LT, and was subsequently switched to PEG IFN‐α‐2b/RBV/TVR. Genotype analysis showed TG genotype of IL‐28 SNP for the donor, and TT genotype of IL‐28 SNP for the recipient. Serum HCV RNA titer decreased below the detection limit at 5 weeks. However, triple therapy was withdrawn at 11 weeks due to general fatigue, which resulted in HCV RNA rebound 4 weeks later. Both patients were treated with cyclosporin, starting with a small dose to avoid interactions with TVR. TVR is a potentially suitable agent for LT recipients who do not respond to PEG IFN‐α‐2b plus RBV after LT.     

Advances in the management of hepatitis C

Significant advances have recently been made in the management of hepatitis C virus (HCV) with many of the changes now part of routine clinical practice. These include the use of non‐invasive methods to assess liver fibrosis, interleukin 28B genotype testing to predict interferon responsiveness and the use of new anti‐viral regimens for HCV genotype 1. Two new antiviral agents (boceprevir and telaprevir) have recently become available in Australia. These protease inhibitors are used in combination with pegylated interferon and ribavirin as triple therapy for genotype 1 HCV. This combination increases sustained virological response from approximately 45–50% to 66–75% in treatment naïve patients. However, these new regimens present novel challenges including complicated treatment algorithms based on virological response, numerous drug interactions and additional side effects especially in patients with advanced fibrosis. The protease inhibitors are the first of many antiviral drugs to become available to treat HCV, heralding the arrival of new agents that will offer greater chances of cure with improved safety and tolerability compared with current therapies.     

IL28B genetic polymorphism testing in the era of direct acting antivirals therapy for chronic hepatitis C: ten years too late?

An association between variations at the IL28B gene locus and HCV clearance (spontaneous recovery or sustained virological response under pegylated interferon (PEG-IFN) and ribavirin (RBV) has been extensively described. In genotype 1-infected patients, the new direct antiviral agents (DAA) including the two approved protease inhibitors boceprevir and telaprevir, in association with the PEG-IFN/RBV combination is the new standard of care making it necessary to redefine the interest of the IL28B genotype in the decision to treat and how to treat genotype 1-infected patients. In treatment-na?ve patients, IL28B status can certainly identify those with a high probability of achieving SVR with response guided therapy and probably in whom the duration of treatment can be markedly reduced. In experienced patients, the impact of IL28B genotypes is limited and cancelled by early viral kinetics. However, the decision to initiate or withhold therapy remains a clinical one. In summary, although it was a major milestone in the treatment of patients with PEG-IFN/RBV, IL28B polymorphism testing entered the clinical arena almost 10 years too late.     

聚乙二醇干扰素联合利巴韦林治疗慢性丙型肝炎的疗效及其影响因素

目的 观察聚乙二醇干扰素(PegIFN)α-2a联合利巴韦林(RBV)治疗慢性丙型肝炎患者的疗效及其影响因素,探讨治疗时间及药物累积用量与疗效之间的关系.方法对117例慢性丙型肝炎患者给予PegIFN α-2a联合RBV抗病毒治疗,PegIFN α-2a每周1次,皮下注射135 μg或180 μg,RBV按体质量每日分次口服800～1200mg,共治疗48周.分别在用药前,用药后4、12、24、36、48周以及停药后24周检测HCV RNA载量,检测部分患者HCV基因型,观察病毒学应答情况并分析影响疗效的因素.计数资料的比较用x2检验,P＜0.05为差异有统计学意义.结果 行基因型检测的29例患者中,1b型HCV感染21例,2a型HCV感染7例,1b和2a型混合HCV感染1例.117例患者中,88例获得了快速病毒学应答,96例(82.1%)获得了持续病毒学应答(SVR).年龄≤40岁、体质量＜75 kg、感染时间＜10年的患者可获得更好的疗效,SVR率明显高于年龄＞40岁、体质量≥75 kg、感染时间≥10年者(91.4%比72.9%,x2=6.796,P＜0.05;85%比50%,x2=5.433,P＜0.05;96.7%比77%,x2=5.852,P＜0.05).坚持全疗程的80%以上及PegIFN α-2a或RBV预计累积用量的80%以上可获得更好的疗效(x2值分别为16.971、16.971和43.212,P值均＜0.01).即使给予患者足够剂量的PegIFN α-2a(≥推荐剂量的80%),RBV减量(＜推荐剂量的80%)亦会使其SVR率下降[75.0%(27/36)比96.8%(60/62),x2=8.762,P＜0.01];获得快速病毒学应答的患者SVR率也明显下降[100.0%(51/51)比81.8%(18/22),x 2=6.614,P＜0.05].结论 PegIFN α-2a联合RBV治疗慢性丙型肝炎疗效显著,坚持80%PegIFN α-2a推荐剂量,80%以上RBV推荐剂量,以及80%推荐疗程可获得更好的疗效.

Abstract：

Objective To evaluate the efficacy and to investigate the association between the length of the treatment period and the cumulative dose of pegylated interferon alpha-2a (PegIFN alpha-2a) plus ribavirin (RBV) and the effectiveness of antiviral therapy. Methods We analyzed data from 117 patients treated for 48 weeks with PEG-IFN alpha-2a (135 μ g or 180 μ g/week) plus weight-based RBV (800 mg/dfor patients ≤65 kg, 1000 mg/d for patients 65-75 kg and 1200 mg/d for patients ≥75 kg) under care at West China Hospital. HCV RNA was assessed at baseline, Week 4, 12 and 24, the end of treatment (EOT) and after 24 weeks follow-up (sustained virological response; SVR) with a test range of 1.0 x 103 to 5.0 x 107 IU/ml.Patients were stratified by age, gender, weight, route of transmission, duration of infection, baseline HCV RNA level and PegIFN alpha-2a or RBV dosage. Results HCV genotype was assessed in 29 patients (genotype 1b, 21; genotype 2a, 7; genotype 1b/2a, 1). Rapid virological response (RVR; HCV RNA negative at week 4), complete early virological response (cEVR; HCV RNA negative at week 12), EOT response, and SVR were achieved in 88 (75.2%), 110 (94%), 114 (97.4%) and 96 (82.1%) patients, respectively. Younger age, lower weight and shorter speculated infection years were associated with higher SVR rates (91.4% vs 72.9%, x2 = 6.796, P ＜ 0.05; 85% vs 50%, x2 = 5.433, P ＜ 0.05; 96.7% vs 77%, x2 = 5.852, P ＜ 0.05). SVR significantly increased with treatment length (38.5%, 66.7%, and 88.8% for ≤ 29 weeks, 29-38 weeks, and ≥38 weeks, respectively). SVR significantly increased with total cumulative treatment doses (38.5%, 66.7% and 88.8% for ≤ 60%, 60%-80% and ≥ 80% of PegIFN dose respectively; 33.3%, 85.3% and 96.8% for ≤ 60%,60%-80% and ≥ 80% in RBV dose respectively) in all patients. Less than 80% of standard dose of RBV was not sufficient even if given enough PegIFN (≥ 80% cumulative treatment dose) in patients who achieved RVR. Conclusion Chinese patients treated with peginterferon alpha-2a plus ribavirin have high rates of SVR.It is important to complete the target length of treatment and to continue the target dosage to achieve SVR.     

Hepatitis c virus markers in infection by hepatitis c virus: In the era of directly acting antivirals

About 130-170 million people are infected with the hepatitis C virus(HCV) worldwide and more than 350000 people die each year of HCV-related liver diseases. The combination of pegylated interferon(Peg-IFN) and ribavirin(RBV) was recommended as the treatment of choice for chronic hepatitis C for nearly a decade. In 2011 the directly acting antivirals(DAA) HCV NS3/4A protease inhibitors,telaprevir and boceprevir,were approved to treat HCV-genotype-1 infection,each in triple combination with Peg-IFN and RBV. These treatments allowed higher rates of SVR than the double Peg-IFN + RBV,but the low tolerability and high pill burden of these triple regimes were responsible for reduced adherence and early treatment discontinuation. The second and third wave DAAs introduced in 2013-2014 enhanced the efficacy and tolerability of anti-HCV treatment. Consequently,the traditional indicators for disease management and predictors of treatment response should be revised in light of these new therapeutic options. This review article will focus on the use of the markers of HCV infection and replication,of laboratory and instrumental data to define the stage of the disease and of predictors,if any,of response to therapy in the DAA era. The article is addressed particularly to physicians who have patients with hepatitis C in care in their everyday clinical practice.