Results of combination treatment with pegylated interferon and ribavirin in cirrhotic patients with hepatitis C infection

Efficacy and safety of sofosbuvir plus ribavirin for Korean patients with hepatitis C virus genotype 2 infection: A retrospective multi-institutional study

BACKGROUND/AIMS

Sofosbuvir plus ribavirin is a standard treatment for patients infected with chronic hepatitis C virus (HCV) genotype 2 in Korea. The purpose of this study was to examine the efficacy and safety of this treatment in Korean patients with chronic HCV genotype 2 infection.

METHODS

We retrospectively analyzed clinical data of patients treated with sofosbuvir plus ribavirin for chronic HCV genotype 2 from May 2016 to December 2017 at eight hospitals located in the Daejeon-Chungcheong area.

RESULTS

A total of 172 patients were treated with sofosbuvir plus ribavirin. Of them, 163 patients completed the treatment, and 162 patients were tested for sustained virologic response 12 weeks after treatment discontinuation (SVR12). Mean age was 59.6±12.3 years (27-96), and 105 (64.4%) patients were female. Of the total patients, 49 (30.1%) were diagnosed with cirrhosis, and 31 of them were treated for 16 weeks. Sofosbuvir plus ribavirin was the first-line treatment for 144 (88.3%) patients. Eleven (6.7%) patients were intolerant to previous interferon-based treatment. Eight (5.0%) patients relapsed after interferon-based treatment. HCV RNA non-detection rate at 4, 8, and 12 weeks was 97.5%, 99.1%, and 99.3%, respectively, and SVR12 was 98.8% (161/163). During treatment, 18 (11.0%) patients had to reduce their administrated dose of ribavirin because of anemia. One patient stopped the treatment because of severe anemia. Other adverse events, including dizziness, indigestion, and headache, were found in 26 (16.0%) patients.

CONCLUSION

A 12-16 week treatment with sofosbuvir plus ribavirin is remarkably effective and well tolerated in Korean patients with chronic HCV genotype 2 infection.

Sofosbuvir plus ribavirin with or without peginterferon for the treatment of hepatitis C virus: Results from a phase 3b study in China

BACKGROUND AND AIM

Sofosbuvir is a nucleotide analog inhibitor of the hepatitis C virus (HCV) NS5B RNA polymerase with pangenotypic potency. This phase 3b study evaluated the safety and efficacy of sofosbuvir + ribavirin ± peginterferon in Chinese patients infected with HCV genotype 1, 2, 3, or 6.

METHODS

Patients with genotype 1 or 6 received sofosbuvir + peginterferon/ribavirin for 12 weeks or sofosbuvir + ribavirin for 24 weeks, depending on prior treatment and interferon eligibility. Patients with genotype 2 or 3 received sofosbuvir + ribavirin for 12 or 24 weeks, respectively. The primary endpoint was sustained virologic response at 12 weeks after the end of treatment (SVR12).

RESULTS

Of 389 patients, 42% had genotype 1, 16% genotype 2, 32% genotype 3, and 9% genotype 6. Half were male, 58% were treatment-naïve, and 15% had cirrhosis. SVR12 rates for patients receiving 12 weeks of sofosbuvir + peginterferon/ribavirin were 94% (95% confidence interval [CI], 87-98%) for HCV genotype 1 and 97% (95% CI, 84-100%) for genotype 6. SVR12 rates for those receiving sofosbuvir + ribavirin for 24 weeks were 95% (95% CI, 87-99%) for genotype 1, 100% (95% CI, 40-100%) for genotype 6, and 95% (95% CI, 90-98%) for genotype 3. For genotype 2 patients receiving sofosbuvir + ribavirin for 12 weeks, the SVR12 rate was 92% (95% CI, 83-97%). Twenty patients (5%) relapsed. Ten (3%) experienced serious adverse events. Three (< 1%) discontinued treatment because of adverse events, of whom one died because of treatment-unrelated adverse events.

CONCLUSIONS

Sofosbuvir-based regimens were highly effective and safe in Chinese patients with HCV genotype 1, 2, 3, or 6, suggesting sofosbuvir could serve as the backbone for HCV treatment in China irrespective of genotype.

Highlights of the Structure-Activity Relationships of Benzimidazole Linked Pyrrolidines Leading to the Discovery of the Hepatitis C Virus NS5A Inhibitor Pibrentasvir (ABT-530)

Curative interferon and ribavirin sparing treatments for hepatitis C virus (HCV)-infected patients require a combination of mechanistically orthogonal direct acting antivirals. A shared component of these treatments is usually an HCV NS5A inhibitor. First generation FDA approved treatments, including the component NS5A inhibitors, do not exhibit equivalent efficacy against HCV virus genotypes 1-6. In particular, these first generation NS5A inhibitors tend to select for viral drug resistance. Ombitasvir is a first generation HCV NS5A inhibitor included as a key component of Viekira Pak for the treatment of patients with HCV genotype 1 infection. Since the launch of next generation HCV treatments, functional cure for genotype 1-6 HCV infections has been achieved, as well as shortened treatment duration across a wider spectrum of genotypes. In this paper, we show how we have modified the anchor, linker, and end-cap architecture of our NS5A inhibitor design template to discover a next generation NS5A inhibitor pibrentasvir (ABT-530), which exhibits potent inhibition of the replication of wild-type genotype 1-6 HCV replicons, as well as improved activity against replicon variants demonstrating resistance against first generation NS5A inhibitors.

A phase IIIb study of ledipasvir/sofosbuvir fixed-dose combination tablet in treatment-naïve and treatment-experienced Korean patients chronically infected with genotype 1 hepatitis C virus

BACKGROUND

The standard-of-care regimen for chronic hepatitis C virus (HCV) infection in Korea, pegylated-interferon-alpha plus ribavirin, is poorly tolerated. Ledipasvir/sofosbuvir is a two-drug, fixed-dose combination tablet approved in the USA, European Union, and Japan for chronic genotype 1 HCV infection.

METHODS

This single-arm, phase IIIb study (NCT02021656) investigated the efficacy and safety of ledipasvir/sofosbuvir fixed-dose combination tablet for 12 weeks in treatment-naïve and treatment-experienced Korean patients chronically infected with genotype 1 HCV with or without compensated cirrhosis.

RESULTS

The proportion of patients with sustained virologic response 12 weeks after treatment discontinuation (SVR12) was 99 % (92/93), with rates of 100 % (46/46) and 98 % (46/47) in treatment-naïve and treatment-experienced patients, respectively. There were no on-treatment failures. One patient relapsed after the end of treatment. The most common treatment-emergent adverse events were headache (8 %, 7/93) and fatigue (6 %, 6/93). There were no grade 3 or 4 adverse events, seven grade 3 laboratory abnormalities, and one premature discontinuation of study treatment (due to nonserious mouth ulceration). None of the three reported serious adverse events were related to treatment.

CONCLUSIONS

These data suggest that 12 weeks of ledipasvir/sofosbuvir is effective and well tolerated in treatment-naïve and treatment-experienced Korean patients with chronic genotype 1 HCV infection.

Treatment of hepatitis C virus genotype 3 infection with direct-acting antiviral agents

Hepatitis C virus (HCV) genotype 3 is responsible for 30.1% of chronic hepatitis C infection cases worldwide. In the era of direct-acting antivirals, these patients have become one of the most challenging to treat, due to fewer effective drug options, higher risk of developing cirrhosis and hepatocellular carcinoma and lower sustained virological response (SVR) rates. Currently there are 4 recommended drugs for the treatment of HCV genotype 3: pegylated interferon (PegIFN), sofosbuvir (SOF), daclatasvir (DCV) and ribavirin (RBV). Treatment with PegIFN, SOF and RBV for 12 weeks has an overall SVR rate of 83–100%, without significant differences among cirrhotic and non-cirrhotic patients. However, this therapeutic regimen has several contraindications and can cause significant adverse events, which can reduce adherence and impair SVR rates. SOF plus RBV for 24 weeks is another treatment option, with SVR rates of 82–96% among patients without cirrhosis and 62–92% among those with cirrhosis. Finally, SOF plus DCV provides 94–97% SVR rates in non-cirrhotic patients, but 59–69% in those with cirrhosis. The addition of RBV to the regimen of SOF plus DCV increases the SVR rates in cirrhotic patients above 80%, and extending treatment to 24 weeks raises SVR to 90%. The ideal duration of therapy is still under investigation. For cirrhotic patients, the optimal duration, or even the best regimen, is still uncertain. Further studies are necessary to clarify the best regimen to treat HCV genotype 3 infection.

A phase 3b study of sofosbuvir plus ribavirin in treatment-naive and treatment-experienced Korean patients chronically infected with genotype 2 hepatitis C virus

In Korea, patients with chronic hepatitis C virus (HCV) infection are typically treated with pegylated interferon-alpha plus ribavirin, but interferons are contraindicated in many patients and are often poorly tolerated, particularly by the elderly and those with advanced liver disease. No interferon-free treatment regimens are approved in Korea. Sofosbuvir is an oral nucleotide analog inhibitor of the HCV nonstructural 5B RNA polymerase. It is approved in the USA, European Union and Japan for treating a number of HCV genotypes, including genotype 2. Genotype 2 has a seroprevalence of 38-46% in Korea. This single-arm, phase 3b study (NCT02021643) examined the efficacy and safety of sofosbuvir plus ribavirin (12-week duration) in chronic genotype 2 HCV-infected treatment-naive and treatment-experienced Korean patients with and without cirrhosis. The proportion of patients with sustained virologic response 12 weeks after treatment discontinuation (SVR12) was 97% (125/129), with 96% (101/105) of treatment-naive and 100% (24/24) of treatment-experienced patients achieving SVR12. Two patients experienced virologic failure (n = 1, on-treatment failure; n = 1, relapse). No patient discontinued study treatment due to an adverse event (AE). The most common treatment-emergent AEs were headache (18%, 23/129) and pruritus (15%, 19/129). Few patients had grade 3 AEs (5%, 6/129) or grade 3 laboratory abnormalities (12%, 15/129). No grade 4 AE was reported. These data suggest that 12 weeks of treatment with the all-oral, interferon-free regimen of sofosbuvir plus ribavirin is effective and well tolerated in Korean patients with chronic genotype 2 HCV infection.

Antiviral Therapy in Patients with Hepatitis C Virus-Induced Cirrhosis

BACKGROUND

Opportunities to treat infection with hepatitis C virus (HCV) are evolving rapidly. From the introduction of interferon (IFN)-α monotherapy in the early 1990s to the approval of telaprevir- and boceprevir-based triple therapies with pegylated (PEG)-IFN-α and ribavirin (RBV) in 2011, the chances of curing patients infected with HCV genotype 1 have improved dramatically to reach approximately 70%. Significant further improvements that may cure virtually all HCV patients with an all-oral, IFN-free regimen are becoming progressively available. Key Messages: Historically, a PEG-IFN/RBV combination therapy of patients with liver cirrhosis was associated with lower virological rates and a worse safety profile. The advent of the first protease inhibitor-based triple therapy was long expected, but the promise fell rapidly because of the numerous side effects and the requirement for intensive clinical management in cirrhotic patients. The newer direct-acting antivirals (DAAs) target the viral polymerase with either nucleos(t)ide analogues or nonnucleosidic inhibitors, the viral protease and the viral NS5A protein. Several clinical trials have now shown that a combination of sofosbuvir (nucleosidic polymerase inhibitor) with daclatasvir or ledipasvir (NS5A inhibitors), or sofosbuvir with simeprevir (protease inhibitor), or a combination of ABT-450 (protease inhibitor) with ritonavir (ABT-450/r), the nonnucleosidic polymerase inhibitor ABT-333 and the NS5A inhibitor ABT-267, can achieve a sustained virological response in up to 95% of naive patients or previously treated patients, even in those who failed prior treatment with first-generation protease inhibitors. The best treatment regimens enable the achievement of comparable results even in cirrhotics, while other regimens still require RBV or a longer treatment duration to achieve optimal results. This improved risk/benefit ratio justifies early access programs of IFN-free regimens for cirrhotic patients. The remaining difficult-to-treat patients are cirrhotics infected with HCV genotype 3 and those with decompensated cirrhosis, for whom novel DAA combinations should be evaluated in clinical trials.

CONCLUSIONS

As new DAAs are becoming available in early access treatment programs, treatment strategy studies are being performed to optimize treatment regimens with respect to the choice of DAAs and treatment duration, based on viral genotypes, prior treatment response and the presence of liver cirrhosis. In the near future, this should allow: (i) a decrease in the complications of HCV-induced cirrhosis, (ii) liver transplantations to be performed in virally cured patients, and (iii) the rescue of patients in the worst clinical situation (decompensated cirrhosis and HCV recurrence on liver graft).

High sustained virological response to pegylated interferon and ribavirin for recurrent genotype 3 hepatitis C infection post-liver transplantation

INTRODUCTION

Treatment outcomes of recurrent HCV genotype 3 (GT-3) after liver transplantation (LT) are ill-defined.

AIMS

To determine efficacy, predictors, and long-term survival after treatment of recurrent HCV GT-3 infection, post-LT, with a combination of pegylated interferon (PEG) and ribavirin (RBV).

METHODS

We studied all LT recipients (LTR) in our program treated with PEG and RBV for recurrent HCV GT-3 between Jan 1st 2002 and Dec 31st 2013. Antiviral therapy (AVT) was started if histology showed recurrent HCV with ≥ stage 2 fibrosis. Treatment was intended for 24 or 36 weeks, depending on early virologic response, and/or 24 weeks consolidation. Primary endpoint was sustained virological response (SVR). We also studied predictors of SVR and long-term patient survival.

RESULTS

Among 492 LT for HCV-related cirrhosis and/or hepatocellular carcinoma performed during the study period, 110 (22%) had HCV GT-3 infection. Fifty-two (10.5%) HCV GT-3 patients had indications for AVT. Six were unable to complete the AVT, three because of clinical decompensation and one each because of metastatic disease involving the brain, lung cancer, and ductopenic rejection. Forty-seven (90%) patients achieved early virological response (EVR) and 37 (71%) achieved SVR. Predictors of SVR were EVR (p < 0.001), stage ≤ 3 fibrosis (p = 0.008), and 36 weeks treatment duration (p < 0.001). Less advanced fibrosis ≤ 3 was independent predictor of SVR (OR 0.18, 95% CI 0.05-0.67). SVR patients had actuarial (Kaplan-Meier) 1, 3, and 10 year post-treatment survival of 100, 100, and 95%, compared with 87, 78, and 20% for non-SVR patients (p < 0.001, log rank test).

CONCLUSION

Efficacy of AVT for recurrent HCV GT-3 post-LT is high, and comparable with that for non-transplant patients. Less advanced fibrosis is an independent predictor of SVR. SVR improves long-term survival.

Consensus interferon plus ribavirin for hepatitis C genotype 3 patients previously treated with pegylated interferon plus ribavirin

BACKGROUND

Not enough data are available about the effectiveness of consensus interferon (CIFN) among HCV genotype 3 patients who failed to respond to pegylated interferon and ribavirin.

OBJECTIVES

We aimed to assess the efficacy and safety of CIFN and ribavirin in non-responders and relapsers to pegylated interferon with ribavirin therapy.

PATIENTS AND METHODS

This open-label investigator-initiated study included 44 patients who received CIFN 15 µg /day plus ribavirin 800-1200 mg daily. In patients with an early virological response (EVR), the dose of CIFN was reduced to 15 µg thrice a week for further 36 weeks. Patients with delayed virological response continued to receive daily CIFN plus ribavirin to complete 48 weeks. The patients were considered "non-responders" if there were less than 2 log reduction in HCV RNA at 12 weeks and detectable HCV RNA at 24 weeks.

RESULTS

Twenty-four patients (55%) were non-responders and 20 patients were relapsers to the previous treatment with pegylated interferon plus ribavirin (mean age 43.6 ± 9.4 years, males 25 (57%)). Nine patients were clinically cirrhotic (Child A). End of treatment virological response was achieved in 19 (43.1%) patients and sustained virological response (SVR) occurred in 12 (27.3%). Out of these 12 patients, eight were non-responders and four were relapsers to the previous treatment. Advanced fibrosis or clinical cirrhosis was associated with low SVR. Adverse events were fever, myalgia, anorexia, depression, and weight loss. Two patients received granulocyte colony stimulating factor for transient neutropenia. Seven patients were given erythropoietin to improve hemoglobin, and six were treated for mild depression. Two patients developed portosystemic encephalopathy.

CONCLUSIONS

More than one-quarter of treatment-experienced patients with HCV genotype 3 achieved SVR after re-treatment with consensus interferon plus ribavirin.

Severe adverse events during antiviral therapy in hepatitis C virus cirrhotic patients: A systematic review

AIM

To identify severe adverse events (SAEs) leading to treatment discontinuation that occur during antiviral therapy in hepatitis C virus (HCV)-infected cirrhotic patients.

METHODS

We identified all the articles published prior to December 2011 in the PubMed, Medline, Lilacs, Scopus, Ovid, EMBASE, Cochrane and Medscape databases that presented these data in cirrhotic patients. These studies evaluated the rate of SAEs leading to discontinuation of standard care treatment: Pegylated interferon (PegIFN) alpha 2a (135-180 μg/wk) or PegIFN alpha 2b (1 or 1.5 μg/kg per week) and ribavirin (800-1200 mg/d). Patients with genotype 1 + 4 underwent treatment for 48 wk, whereas those with genotypes 2 + 3 were treated for 24 wk.

RESULTS

We included 17 papers in this review, comprising of 1133 patients. Treatment was discontinued due to SAEs in 14.5% of the patients. The most common SAEs were: severe thrombocytopenia and/or neutropenia (23.2%), psychiatric disorders (15.5%), decompensation of liver cirrhosis (12.1%) and severe anemia (11.2%). The proportion of patients who needed to discontinue their therapy due to SAEs was significantly higher in patients with Child-Pugh class B and C vs those with Child-Pugh class A: 22% vs 11.4% (P = 0.003). A similar discontinuation rate was found in cirrhotic patients treated with PegIFN alpha 2a and those treated with PegIFN alpha 2b, in combination with ribavirin: 14.2% vs 13.7% (P = 0.96). The overall sustained virological response rate in cirrhotic patients was 37% (95%CI: 33.5-43.1) but was significantly lower in patients with genotype 1 + 4 than in those with genotype 2 + 3: 20.5% (95%CI: 17.9-24.8) vs 56.5% (95%CI: 51.5-63.2), (P < 0.0001).

CONCLUSION

Fourteen point five percent of HCV cirrhotic patients treated with PegIFN and ribavirin needed early discontinuation of therapy due to SAEs, the most common cause being hematological disorders.

Safety and efficacy of treatment for chronic hepatitis C with a focus on pegylated interferons: the backbone of therapy today and in the future

INTRODUCTION

Approximately 170 million people are infected with HCV. The efficacy of treatment for chronic hepatitis C has increased markedly over the last 2 decades. Optimal patient management requires thorough knowledge of the adverse effect profiles of drugs used for this condition and strategies to mitigate these effects.

AREAS COVERED

The efficacy, safety and tolerability data associated with IFN-based therapy, with particular attention given to the two licensed pegylated IFNs (peg-IFNs), are identified by focused searches of Medline. Recommendations for the management of adverse events are also given. Focused searches of PubMed are done using the terms peginterferon and chronic hepatitis C. The results of large randomized clinical trials are emphasized.

EXPERT OPINION

Patients receiving treatment with peg-IFN plus ribavirin for chronic hepatitis C must be monitored closely for adverse events. These events can be effectively managed to maximize patients' adherence and thus the chance of treatment success. Direct-acting antiviral agents are expected to be approved in the near future and will be used in select patients with a peg-IFN plus ribavirin 'backbone'.

Pegylated interferon and ribavirin combination therapy for chronic hepatitis C virus infection in patients with Child-Pugh Class A liver cirrhosis

OBJECTIVE

Pegylated interferon (peg-IFN) and ribavirin (RBV) treatment is less effective in patients with hepatitis C virus (HCV) and liver cirrhosis than in non-cirrhotic patients. Many patients with advanced liver disease have been excluded from the pivotal randomized controlled studies. The aim of this study was to investigate the efficacy and tolerability of combination therapy in unselected patients with Child-Pugh Class A liver cirrhosis at a Swedish university clinic.

MATERIAL AND METHODS

The virologic response and adverse events were retrospectively analyzed in 104 patients with HCV-associated Child-Pugh Class A liver cirrhosis who had been treated with peg-IFN and RBV.

RESULTS

Overall sustained virologic response (SVR) was achieved in 13% genotype 1-, 60% genotype 2-, and 31% genotype 3-infected patients. In treatment-naive patients, the corresponding rates were 13%, 82%, and 38%, respectively. In 46% of patients, treatment was discontinued prematurely owing to lack of virologic response in the majority.

CONCLUSIONS

SVR rates found in our study, in particular for genotype 1 patients (13%), were lower than those generally found in randomized controlled studies. For cirrhotic patients, new treatment alternatives are urgently needed to improve treatment outcome.

Partial splenic embolization prior to combination therapy of interferon and ribavirin in chronic hepatitis C patients with thrombocytopenia

AIM

A low platelet count leads to dose reduction of interferon (IFN) and is associated with failure to achieve a sustained virological response (SVR) in chronic hepatitis C patients. However, partial splenic embolization (PSE) is effective for treating thrombocytopenia resulting from hypersplenism.

METHODS

We compared the clinical features of 10 patients receiving PSE prior to the combination therapy of IFN and ribavirin (RBV) (PSE group) with those of 10 non-receiving PSE patients (non-PSE group).

RESULTS

In all 10 patients, PSE was successfully performed without serious adverse events. After PSE, leukocyte, neutrophil, and platelet counts significantly increased. The period from PSE to the initiation of the combination therapy was 15 (7-21) days. In the PSE group, two of six patients (33%) infected with genotype 1, and all four patients infected with genotype 2, achieved SVR. In the non-PSE group, only three patients infected with genotype 2 achieved SVR. Two patients in the PSE group and one in the non-PSE group discontinued the combination therapy. Three patients of the PSE group and five of the non-PSE group reduced the dose of pegylated IFN-alpha-2b because of thrombocytopenia. In the PSE group, platelet counts during the combination therapy fell to baseline levels; however, they did not fall to lower levels than baseline levels. In the non-PSE group, platelet counts 1 month after the initiation of the therapy were lower than baseline levels.

CONCLUSION

The increase of platelet counts after PSE may allow the safe use of IFN and RBV and improve the SVR rate in chronic hepatitis C patients with thrombocytopenia.

Interferon-alpha 2b-induced thrombocytopenia is caused by inhibition of platelet production but not proliferation and endomitosis in human megakaryocytes

Human interferon (IFN)-alpha is the standard therapy for chronic hepatitis C to prevent its progression to liver cirrhosis and hepatocellular carcinoma. Thrombocytopenia is one of the major adverse effects of IFN-alpha and often leads to dose reduction or treatment discontinuation. However, there is little information on how IFN-alpha inhibits human megakaryopoiesis. In this study, we demonstrated that IFN-alpha did not inhibit colony formation of megakaryocytes from human CD34(+) hematopoietic stem cells. IFN-alpha did not inhibit endomitosis but did inhibit cytoplasmic maturation of megakaryocytes and platelet production in vitro. IFN-alpha suppressed the expression of transcription factors regulating late-stage megakaryopoiesis, such as GATA-1, p45(NF-E2), MafG. IFN-alpha also significantly reduced the number of human platelets but not megakaryocytes, and did not inhibit endomitosis of human megakaryocytes in immunodeficient NOD/Shi-scid/IL-2R gamma(null) (NOG) mice transplanted with human CD34(+) cells (hu-NOG). We also demonstrated that a novel thrombopoietin mimetic, NIP-004, was effective for treating IFN-alpha-induced thrombocytopenia in hu-NOG mice. From ultrastructural study, IFN-alpha inhibited the maturation of demarcation membranes in megakaryocytes, although NIP-004 prevented the inhibitory effects of IFN-alpha. These results defined the pathogenesis of IFN-alpha-induced thrombocytopenia and suggested possible future clinical applications for thrombopoietin mimetics.

Peginterferon alfa-2b and ribavirin combination therapy for chronic hepatitis C

Pegylated interferon and ribavirin have been the standard treatment for chronic hepatitis C (CHC) since 2001. In the USA, hepatitis C is the most common blood-borne infection and the leading cause of cirrhosis requiring liver transplantation. Due to heightened awareness, more patients are being screened and diagnosed with CHC. Interferon-based therapy will continue to be a mainstay of treatment for years to come. A familiarity with the drugs used for the treatment of CHC is beneficial for most healthcare providers. This article will discuss the use of peginterferon alfa-2b and ribavirin, including dosing, length of treatment, mechanism of action, pharmacodynamics, pharmacokinetics, side effects, monitoring and contraindications, and will provide a future perspective on the treatment of CHC.

Antiviral therapy: chronic hepatitis C

The combination of pegylated interferon (IFN) with ribavirin is the standard of care for chronic hepatitis C. Response rates range from 50 to 90% for genotype 1 and 2/3 which also differ in the duration of treatment (48 vs 24 weeks, respectively). Therapy if given with weight-based dosing may be shortened from 24 to 12, 14 or 16 weeks (genotypes 2 and 3), and from 48 to 24 weeks (genotype 1) in case of hepatitis C virus (HCV) clearance at week 4, without reducing sustained virologic response (SVR). Conversely, prolonging treatment for 72 weeks in those with only a decrease of viral load at week 4, i.e. "slow responders" increases SVR rates by preventing relapse. In spite of such progress, over half of patients are relapsers or nonresponders. If the previous treatment was suboptimal, retreatment with higher doses or longer duration may be beneficial unless an individual was a 'null responder' previously. New promising anti-HCV molecules (antiproteases and antipolymerases), some with potent antiviral activity, are in phase II trials but appear to require the addition of IFN and ribavirin to maintain viral suppression. Other immunomodulatory agents such as new IFN or therapeutic vaccines and alternatives to ribavirin are also under development. Future regimens should improve efficacy and provide shorter and better-tolerated combination therapy.