Successful Treatment With Novel Triple Drug Combination Consisting of Interferon-γ, Interferon Alfacon-1, and Ribavirin in a Nonresponder HCV Patient to Pegylated Interferon Therapy

Despite major advances in therapy of hepatitis C over the past decade, nearly half of the patients treated with the currently available regimens do not clear the virus. Therefore, there is a large unmet need for more effective therapy for patients who have failed pegylated interferon plus ribavirin therapy. We describe a case of a HCV genotype 1b patient who had failed previous combination therapies of interferon plus ribavirin and pegylated interferon plus ribavirin and was subsequently successfully treated with a novel triple drug combination consisting of interferon-γ plus interferon alfacon plus ribavirin with the outcome of a sustained virologic response. This triple drug therapy combination could be an option for patients who have failed therapies with currently available pegylated interferons plus ribavirin. Prospective randomized studies are required to evaluate the effectiveness and tolerability of this regimen in this patient population.     

Treatment of HCV infection with pegylated interferons

The past decade has seen advances in the treatment of chronic hepatitis C infection. Therapy with interferon alpha was disappointing, with only 15% of patients achieving longterm viral clearance. Combination therapy with interferon alpha and ribavirin therapy more than doubled sustained virologic response (SVR) rates. The pegylated interferons are a recent development that have improved the outlook for patients with chronic hepatitis C virus (HCV). Pegylated interferons are produced by the binding of polyethylene glycol to interferon alpha, which results in a compound with improved pharmacokinetic properties with increased efficacy. Combination therapy with pegylated interferon alpha and ribavirin is the optimal treatment for chronic HCV infection. Up to 80% of patients with genotype 2/3 infection and up to 50% of patients with genotype 1 infection achieve SVR with treatment. For the first time, the majority of patients with chronic HCV who are treated can anticipate a long-term cure.     

Pegylated interferons: What role will they play in the treatment of chronic hepatitis C?

The primary therapy for patients with chronic hepatitis C virus (HCV) infection is interferon. Unfortunately, standard interferon, because of its very short half-life and side-effect profile, has limited efficacy in most patients with this disease. Pegylated interferons are produced by attaching the inert polymer, polyethylene glycol, to the standard interferon alpha protein. This process enhances the biological activity of interferon, primarily by prolonging the half-life, when compared with the native protein. To date, two types of pegylated interferon alpha have been developed. Both of these products have been shown to be superior to standard interferon, at both eradicating HCV RNA during therapy and at achieving a sustained virologic response. When combined with ribavirin, treatment with pegylated interferon can achieve sustained virologic response in approximately 42% of patients infected with HCV genotype 1 and 80% of patients with HCV genotypes 2 or 3.     

慢性丙型肝炎治疗新纪元——口服逆转录酶和蛋白酶抑制剂的临床应用

慢性丙型肝炎患者经过聚乙二醇干扰素（PEG—IFN）联合利巴韦林（RBV）治疗后,多数患者可以获得临床治愈,即停药随访6个月后病毒仍然检测不到,且疾病不再进展。然而,还有相当一部分患者因为不能耐受IFN或RBV而未完成标准治疗,或对治疗完全无应答,或停药后复发,或由于疾病发现较晚而失去了抗病毒治疗的时机。因此,在临床上仍然需要新的抗病毒药物,或者和IFN联合治疗,或者单独治疗。本文将就近年来研发的12服逆转录酶和蛋白酶抑制剂的直接抗病毒药物的临床研究和应用作一综述。     

Peginterferon alone or with ribavirin enhances HCV-specific CD4 T-helper 1 responses in patients with chronic hepatitis C

BACKGROUND & AIMS: Pegylated interferons (IFNs) with or without ribavirin were shown in several studies to improve sustained virologic response compared with standard IFN alpha-2 therapy. This study investigated if the greater efficacy of pegylated IFNs might be related to modulation of immunologic responses. METHODS: Hepatitis C virus (HCV)-specific CD4+ T-cell responses and cytokine production to various HCV proteins (Elispot assay) in peripheral blood were prospectively assessed in 42 patients receiving IFN alpha-2a monotherapy, peginterferon (PEG IFN) alpha-2a monotherapy, or PEG IFN alpha-2a plus ribavirin and correlated to the outcome of therapy. RESULTS: The sustained virologic response rate was significantly higher in the PEG IFN groups (42% in PEG IFN alpha-2a monotherapy and 57% in PEG IFN alpha-2a/ribavirin combination) than in the standard IFN alpha-2a group (14%). The sustained response was 48% in HCV genotype 1 patients treated with PEG IFN alpha-2a/ribavirin therapy. Pretreatment HCV-specific CD4+ responses were either weak or absent. PEG IFN alone or combined with ribavirin induced significant increase in the frequency, strength, and breadth of HCV-specific CD4+ T-cell responses with type 1 predominance; whereas interferon alpha-2a monotherapy was associated with lower, fluctuating, short-lived responses. Sustained responders maintained multispecific HCV-specific CD4+ T-cell responses with enhanced IFN-gamma production. Relapsers and partial responders initially displayed significant HCV-specific CD4+ T-cell responses that waned or were lost. CONCLUSIONS: The efficacy of PEG IFN alpha-2a alone or in combination with ribavirin in inducing high rates of sustained virologic response may be owing to the higher efficacy of PEG IFN in induction and maintenance of significant multispecific HCV-specific CD4+ T-helper 1 responses.     

Consensus Interferon and Ribavirin in Patients with Chronic Hepatitis C Who Were Nonresponders to Pegylated Interferon alfa-2b and Ribavirin

Recent studies suggest that consensus interferon and ribavirin is effective in retreating patients with chronic hepatitis C who failed therapy with interferon alfa and ribavirin. The objective of the present study was to assess the efficacy, safety, and tolerability of consensus interferon and ribavirin in patients who did not respond to pegylated interferon alfa-2b and ribavirin. We retrospectively identified 137 consecutive nonresponders to pegylated interferon alfa-2b and ribavirin and initiated patients on daily treatment with consensus interferon 15 mug subcutaneously and weight-based ribavirin for 48 weeks. If patients were HCV RNA negative at 12 weeks, the dose was reduced to 15 mug three times weekly for the remaining 36 weeks. The sustained virologic response rate was 37%. Daily consensus interferon therapy was safe and well tolerated in all patients. No dose reductions were required, and no patient discontinued therapy. Further studies of consensus interferon and ribavirin in nonresponders are warranted.     

Advances in the treatment of hepatitis C in children and adolescents

Progress is being made in the treatment of hepatitis C virus (HCV) infection in adults. The current recommended strategy is to use the combination of pegylated-interferon and ribavirin, which leads to a sustained virologic response rate in 50% to 60% of individuals eligible for treatment. Less is known about HCV infection in the pediatric population. Recently, small and uncontrolled studies have suggested that combination therapy of interferon alpha with ribavirin improves the outcome of HCV-infected children. There are no data yet regarding the use of pegylated interferons in pediatrics. This article summarizes what is known about the treatment of HCV in children and adolescents, and discusses future areas of research as they may pertain to the idiosyncrasies of the pediatric population.     

Effect of ribavirin in genotype 1 patients with hepatitis C responding to pegylated interferon alfa-2a plus ribavirin

BACKGROUND & AIMS: Pegylated interferon alfa-ribavirin combination is the standard treatment for chronic hepatitis C, but the mechanisms by which ribavirin enhances the rate of sustained hepatitis C virus (HCV) eradication remain unknown. We aimed to investigate the role of ribavirin in HCV clearance during therapy and to evaluate the consequences of ribavirin discontinuation in patients infected with genotype 1 hepatitis C who cleared HCV RNA at week 24. METHODS: A total of 516 patients were treated with pegylated interferon alfa-2a, 180 microg/wk, plus ribavirin, 800 mg/day. Seventy percent were RNA negative at week 24. They were randomized to continue with the combination or receive pegylated interferon alone. RESULTS: Responders at week 24 who stopped ribavirin had a significantly higher rate of breakthroughs during, and relapses after, therapy (sustained virologic response, 52.8% vs 68.2%; P = .004), but their side-effect profile and quality of life tended to improve. Multiple logistic regression analysis in the pegylated interferon alfa monotherapy group allowed identification of responders at week 24 who could stop ribavirin without losing their chance of a sustained virologic response, based on baseline viral load and age. Forty-eight weeks of ribavirin may not be needed when HCV RNA is undetectable at week 2. CONCLUSIONS: We made 3 conclusions from this study. First, ribavirin primarily acts by sustaining the virologic response to pegylated interferon alfa; second, ribavirin must be administered for the full treatment duration in most genotype 1-infected patients who respond; third, baseline parameters may help identify patients who could discontinue ribavirin or reduce the dose without losing their chance of success.     

Recent Ⅳ-drug users with chronic hepatitis C can be efficiently treated with daily high dose induction therapy using consensus interferon: An open-label pilot study

AIM: To investigate the use of high dose consensusinterferon in combination with ribavirin in former iv drug users infected with hepatitis C.METHODS: We started, before pegylated (PEG)interferons were available, an open-label study to investigate the efficacy and tolerability of high dose induction therapy with consensus interferon (CIFN) and ribavirin in treatment of naiive patients with chronic hepatitis C. Fifty-eight patients who were former iv drug users, were enrolled receiving 18 μg of CIFN daily for 8 wk, followed by 9 μg daily for up to wk 24 or 48 and 800 mg of ribavirin daily. End point of the study was tolerability and eradication of the virus at wk 48 and sustained virological response at wk 72.RESULTS: More than 62% of patients responded to the treatment with CIFN at wk 24 or 48, respectively,showing a negative qualitative PCR [genotype 1 fourteen patients (56%), genotype 2 five (50%),genotype 3 thirteen (87%), genotype 4 four (50%)].Forty-eight percent of genotype 1 patients showed sustained virological response (SVR) six months after the treatment.CONCLUSION: CIFN on a daily basis is well tolerated and side effects like leuko- and thrombocytopenia are moderate. End of therapy (EOT) rates are slightly lower than the newer standard therapy with pegylated interferons. CIFN on a daily basis might be a favourable therapy regimen for patients with GT1 and high viral load or for non-responders after failure of standard therapy.     

Pegylated interferon alfa-2b plus ribavirin in the retreatment of interferon-ribavirin nonresponder patients

BACKGROUND & AIMS: Inadequate data are available about retreatment of nonresponders to interferon (IFN) and ribavirin. Thus, this study evaluated the efficacy and tolerability of a 48-week therapy with pegylated IFN-alpha-2b plus high-dose ribavirin in patients who have failed to respond to the combination. Treatment up to 48 weeks also in patients who have failed to clear hepatitis C virus (HCV) RNA by week 24 was also evaluated. METHODS: One hundred forty-one patients who previously did not respond to IFN and ribavirin, 86% with genotype 1 or 4 infection, 52% with high viral load (>800.000 IU/mL), 22% with cirrhosis, were retreated with pegylated IFN-alpha-2b 1.5 microg/kg per week and ribavirin 1000-1200 mg/day for 48 weeks and followed up for 24 weeks. RESULTS: By intent-to-treat analysis, 20% of patients achieved a sustained virologic response (SVR). SVR of genotype 1 patients was 19%. Independent predictors of SVR were low gamma-glutamyltransferase levels (OR, 22.9; 95% CI: 6.6-79.6) and low viral load (OR, 3.8; 95% CI: 1.1-12.6). Twelve (23%) out of 51 patients who were HCV RNA positive after 24 weeks of therapy achieved a late virologic response (after week 24) and 5 (10%) of them, all with genotype 1, achieved an SVR. Genotype was not associated with response (P = .2) or with early response (P = .3). CONCLUSIONS: Retreatment with pegylated IFN-alpha-2b and ribavirin of multi-experienced and "difficult to treat" nonresponder patients produced a very promising SVR. Accurate selection of patients, such as those with low viral load and low gamma-glutamyltransferase levels, and prolongation of therapy beyond 24 weeks also in HCV RNA-positive patients may further increase the rate of SVR.     

Treatment of chronic hepatitis C in patients who have failed to respond to IFN or IFN and ribavirin combination therapy

Approximately 45% of patients with chronic hepatitis C infection fail to achieve a sustained virologic response when treated with pegylated interferon (IFN) and ribavirin combination therapy. The lack of early virologic response after 12 to 24 weeks of therapy can be a reliable indicator of those who will not benefit from continuing the treatment for 48 weeks. The presence of genotype 1, high viral load, and advanced fibrosis are among the factors that can predict those patients who have higher rates of nonresponse. Nonresponders to IFN monotherapy and IFN plus ribavirin combination therapy can benefit from retreatment with pegylated IFN and ribavirin combination therapy. Treatment options for nonresponders to pegylated IFN and ribavirin are being investigated in several trials. The role of maintenance pegylated IFN is also under investigation, although preliminary evidence suggests that some patients may derive benefit.     

Management of patients coinfected with HCV and HIV: a close look at the role for direct-acting antivirals

With the development of effective therapies against human immunodeficiency virus (HIV), hepatitis C virus (HCV) infection has become a major cause of morbidity and mortality among patients with both infections (coinfection). In addition to the high prevalence of chronic HCV, particularly among HIV-infected injection drug users, the rate of incident HIV infections is increasing among HIV-infected men who have sex with men, leading to recommendations for education and screening for HCV in this population. Liver disease is the second leading and, in some cases, a preventable cause of death among coinfected patients. Those at risk for liver disease progression are usually treated with a combination of interferon (IFN) and ribavirin (RBV), which is not highly effective; it has low rates of sustained virologic response (SVR), especially for coinfected patients with HCV genotype 1 and those of African descent. Direct-acting antivirals might overcome factors such as immunodeficiency that can reduce the efficacy of IFN. However, for now it remains challenging to treat coinfected patients due to interactions among drugs, additive drug toxicities, and the continued need for combination therapies that include pegylated IFN. Recently developed HCV protease inhibitors such as telaprevir and boceprevir, given in combination with pegylated IFN and RBV, could increase the rate of SVR with manageable toxicity and drug interactions. We review the latest developments and obstacles to treating coinfected patients.     

Enhanced efficacy of pegylated interferon alpha‐2a over pegylated interferon and ribavirin in chronic hepatitis C genotype 4A randomized trial and quality of life analysis

Aim: The therapy of chronic hepatitis C genotype 4 (HCV‐4) has not been optimized yet. This randomized, prospective, parallel‐group clinical trial compared the efficacy and safety of pegylated interferon α‐2a (PEG‐IFN α‐2a) plus ribavirin and PEG‐IFN α‐2b plus ribavirin and assessed the health‐related quality of life (HRQOL) in patients with chronic HCV‐4. Methods: Eligible patients with proven chronic HCV‐4 were randomized to receive either a weekly dose of PEG‐IFN α‐2a (180 μg) or PEG‐IFN α‐2b (1.5 μg/kg) and a daily dose of ribavirin (1000–1200 mg) for 48 weeks with 24 weeks post‐treatment follow‐up. The primary end point was sustained virological response (SVR) defined by undetectable HCV RNA 24 weeks after treatment. The Short form‐36 Health Survey version 2 (SF‐36v2) and the Chronic Liver Disease questionnaires (CLDQ) were assessed before, during and after therapy. Results: The overall SVR rate of the entire cohort was 59.9%. The SVR rates were significantly higher in patients treated with PEG‐IFN α‐2a and ribavirin (Group A; n=109) compared with those treated with PEG‐IFN α‐2b and ribavirin (Group B; n=108, 70.6 vs. 54.6%, respectively; P=0.017). The relapse rates were 5.1% for PEG‐IFN α‐2a and 15.7% for PEG‐IFN α‐2b (P=0.0019). The SF‐36v2 and CLDQ were low during therapy and improved significantly after therapy successful therapy. Conclusion: Pegylated interferon α‐2a plus ribavirin was significantly more effective than PEG‐IFN α‐2b and ribavirin therapy in the treatment of chronic HCV‐4 patients. The tolerability and adverse events were comparable between the two regimens. The HRQOL improved significantly after successful PEG‐IFN α‐2a plus ribavirin therapy.     

Early virologic response after peginterferon alpha-2a plus ribavirin or peginterferon alpha-2b plus ribavirin treatment in patients with chronic hepatitis C

Patients infected with hepatitis C virus (HCV) genotype 1 and with serum HCV RNA concentrations over 800 000 IU/mL have relatively low rates of virologic response to pegylated interferons. The 2 forms of pegylated interferon have different pharmacokinetic profiles, and pilot studies comparing them have yielded varying results. We compared the virologic response to 12 weeks of treatment with peginterferon alpha-2a plus ribavirin vs peginterferon alpha-2b plus ribavirin in 380 patients who were infected with HCV genotype 1 and had high viral loads. We observed no between-group differences in viral load reduction over time and no differences in the percentage of patients treated with peginterferon alpha-2a or peginterferon alpha-2b plus ribavirin who achieved early virologic response (EVR), defined as >/=2-log reduction in HCV RNA concentration or undetectable HCV RNA at 12 weeks (66%vs 63%). Serum levels of interferon were more frequently below the level of quantitation in patients treated with peginterferon alpha-2b plus ribavirin (58-68%) than in those treated with peginterferon alpha-2a plus ribavirin (1-2%). Patients treated with peginterferon alpha-2b plus ribavirin had higher rates of discontinuation for safety reasons (6%vs 1%). In conclusion, a substantial percentage of patients infected with HCV genotype 1 and high viral load can achieve EVR when treated with peginterferon and ribavirin. The 2 pegylated interferons showed comparable anti-HCV activity during the first 12 weeks of treatment when combined with the same doses of ribavirin (1000-1200 mg/day), but discontinuations for safety reasons were higher in the patients treated with peginterferon alpha-2b plus ribavirin.     

Treatment of chronic hepatitis C in patients with haemophilia: a review of the literature

Summary. Chronic hepatitis C is a major cause of morbidity and mortality in haemophilia patients. In contrast to studies in the general population, the studies of antiviral therapy in haemophilia patients are limited and often include small numbers of patients. A review of the literature was performed to assess the efficacy of interferon (IFN)‐based therapy for patients with haemophilia chronically infected with hepatitis C virus (HCV). Studies were identified by electronic searches (Medline, Embase) and hand searches in references of key articles. Data of the included studies were pooled, and responses to therapy were stratified according to treatment regimen, HIV co‐infection status, and treatment history. The main outcome was a sustained virological response (SVR) defined as absence of HCV RNA both at the end of treatment and 24‐week post‐treatment. Thirty‐five studies were identified that included 1151 patients. After pooling the data of included patients, the SVR in HIV‐negative treatment naïve patients was 22% for IFN monotherapy, 43% for IFN and ribavirin, and 57% for pegylated IFN and ribavirin, respectively. Re‐treatment with IFN and ribavirin of those who failed to respond to previous IFN monotherapy was successful in 33%. In HCV/HIV‐coinfected patients, response to IFN monotherapy was 8% and to IFN combined with ribavirin 39%. Responses to IFN‐based therapy in patients with haemophilia have been improved over time and are nowadays approximately 50–60%. However, data on haemophilic HCV/HIV‐coinfected patients and in patients who failed to respond to previous therapy are limited and future studies in these specific patient population are necessary.     

Hepatitis B virus/hepatitis C virus coinfection: epidemiology, clinical features, viral interactions and treatment

Because of the shared modes of transmission, hepatitis B virus (HBV)/hepatitis C virus (HCV) coinfection is not uncommon in highly endemic areas and among subjects with a high risk of parenteral infections. The worldwide prevalence of HBV/HCV coinfection is unknown and might be underestimated with the phenomenon of silent (occult) HBV infection. HCV superinfection in patients with chronic HBV infection was the most common clinical features of coinfection in Asia-Pacific countries. Further, most, but not all, clinical observations suggested that interference between the two viruses was more frequently characterized by an inhibition of HBV replication exerted by HCV. However, longitudinal follow-up studies have demonstrated that the virological patterns in coinfection cases are widely divergent and have dynamic profiles over time. As compared with monoinfected patients, HBV/HCV coinfected persons tend to have more severe liver injury, a higher probability of liver cirrhosis and hepatic decompensation, and a higher incidence of hepatocellular carcinoma. Detailed serological and virological evaluations are required for coinfected patients before initiation of antiviral therapy. Previous studies demonstrated that HBV/HCV coinfected patients responded poorly to interferon (IFN) monotherapy. Currently, for patients with dominant HCV infection and low level HBV viremia (<10(4) IU/mL), IFN or pegylated IFN plus ribavirin can achieve comparable sustained virus response as expected with HCV monoinfection. However, phenomenon of reciprocal viral interference can happen, and resultant "flare" of hepatitis activity may cause liver function deterioration. For coinfected patients with dually-active HBV/HCV, the optimal regimen for therapy remains unclear although adding oral nucleos(t)ide analogs to pegylated IFN and ribavirin seems a reasonable empiric option.     

Splenectomy and antiviral treatment for thrombocytopenic patients with chronic hepatitis C virus infection

Summary. Thrombocytopenic patients with chronic hepatitis C virus (HCV) infection are poor candidates for antiviral treatment with interferon (IFN), but no standard treatment for thrombocytopenia has yet been established. We evaluated the safety of splenectomy and its efficacy for the initiation and continuation of antiviral therapy. From March 2003 to April 2006, 10 patients (mean age 62.5 years) with HCV‐related cirrhosis, low platelet count (≦106 000/mm³) and splenomegaly (spleen size ≧10 cm) underwent splenectomy. Platelet counts significantly increased at 4–8 weeks after splenectomy [pre: 64 200 ± 6900/mm³vs post 209 000 ± 40 600/mm³ (P = 0.004)]. No severe operative complications were observed. All patients subsequently received antiviral therapy. Of the eight patients who were infected with HCV genotype 1 and had a high viral load (≧100 KIU/mL), four received combination therapy with pegylated IFNα‐2b plus ribavirin, and the other four received standard IFNα‐2b plus ribavirin. One patient infected with HCV genotype 2 and another with HCV genotype 1 and a low viral load (<100 KIU/mL) were treated with pegylated IFNα‐2a. Six patients achieved sustained virologic response (SVR). Among four patients who failed to achieve SVR, one was given retreatment with pegylated IFN plus ribavirin, and the other three received low‐dose long‐term IFN therapy. Although this study was small, the treatment results were similar to those for patients without thrombocytopenia and suggested that splenectomy would not reduce the antiviral efficacy of IFNα‐based treatment.     

Firstline treatment for hepatitis C: combination interferon/ribavirin versus interferon monotherapy

In the initial treatment of chronic hepatitis C, interferon‐alfa (IFN‐α) monotherapy for 24–48 weeks induces sustained response rates of only 10–20%. Combination therapy with IFN‐α plus ribavirin induces a sustained response in 40–50% of patients, and can be now recommended as the firstline therapy for chronic hepatitis C. Stopping therapy at week 12 because of persistent viraemia is unnecessary with the combination therapy because later clearance of HCV RNA can still occur with a sustained response. Patients with HCV genotype 1 should receive 48 weeks of combination therapy, in contrast to 24 weeks for patients with genotypes 2 or 3. For patients who cannot tolerate the side effects of ribavirin, such as anaemia, IFN‐α at 3 MU three times weekly for 48 weeks is preferred as the initial therapy. The long‐acting pegylated IFN can be expected to enhance the efficacy of combination therapy in the treatment of chronic hepatitis C and appears to be much more potent as monotherapy. Further studies are needed to improve the current ‘half‐full’ status of chronic hepatitis C treatment.     

Chronic hepatitis C treatment patterns in African American patients: an update

There are large racial disparities in the incidence of chronic hepatitis C virus (HCV) infection in the United States. The prevalence of HCV, and the prevalence of infection with HCV genotype 1, is higher among African Americans than among other ethnic groups. African Americans also have a higher incidence of complications of HCV infection, including a higher incidence of antibodies to HCV RNA and higher incidences of occurrence of and mortality from hepatocellular carcinoma. Combination therapy with pegylated interferons and ribavirin has increased the sustained virologic response (SVR) rates, and decreased the rates and severity of adverse events, over those observed with standard interferons, with or without ribavirin, although SVR rates with peginterferons plus ribavirin are lower in African Americans than in other ethnic groups. A recent clinical trial of peginterferon alpha-2a plus ribavirin in African American patients resulted in a higher SVR rate, 26%, than observed previously, and 90% of patients showed stabilization or improvement in fibrosis. No host or viral genetic differences have yet been identified to explain the racial disparities in incidence of HCV or response to treatment, but clinical trials are currently ongoing to identify these factors. Because treatment with pegylated interferons plus ribavirin yields improved SVR rates with good tolerability, while the basis for lower response rates in African Americans is not yet known, it is recommended that all patients with chronic HCV infection, regardless of ethnic or racial background, receive combination therapy.     

Therapeutic modalities in hepatitis C: challenges and development

Our understanding of the pathogenicity of hepatitis C virus (HCV) is based on patients infected chronically for >20 years. The lack of a suitable animal model, the narrow host range of the virus, and the protracted onset of liver disease induced by HCV have hampered advances in treatment. In spite of these problems, we identified patient and viral characteristics that predict responses to current therapies, including HCV genotype, viral load, body weight, age, liver histology, co-infection with HIV and treatment adherence and tolerance. Interferon (IFN) alpha was the first therapy for chronic HCV infection. The combination of IFN plus ribavirin increases sustained virological response rates compared with IFN alone. Two pegylated IFNs have been developed and are widely approved for the treatment of chronic hepatitis C: peginterferon alpha-2a (40 KD), and pegylated IFN alpha-2b (12 KD). These products have reduced systemic clearance, prolonged half-lives and reduced antigenicity compared with conventional IFN. The reduced clearance results in sustained plasma levels of the drug and allows for once-weekly dosing. Pegylated IFN alpha-2b (12 KD) has a small, linear polyethylene glycol (PEG) moiety and has an intermediate duration of activity; peginterferon alpha-2a (40 KD) incorporates a large, branched-chain PEG moiety and has a longer half-life than both conventional IFN alpha and pegylated IFN alpha-2b (12 KD). The combination of a pegylated IFN plus ribavirin significantly increases sustained virological response rates compared with conventional IFN plus ribavirin in patients with chronic hepatitis C and is now recognized as the standard of care for these patients.