Re-treatment with interferon-beta of patients with chronic hepatitis C virus infection

Host Cell Targets in HCV Therapy: Novel Strategy or Proven Practice?

The development of novel antiviral drugs against hepatitis C is a challenging and competitive area of research. Progress of this research has been hampered due to the quasispecies nature of the hepatitis C virus, the absence of cellular infection models and the lack of easily accessible and highly representative animal models. The current combination therapy consisting of interferon-α and ribavirin mainly acts by supporting host cell defence. These therapeutics are the prototypic representatives of indirect antiviral agents as they act on cellular targets. However, the therapy is not a cure, when considered from the long-term perspective, for almost half of the chronically infected patients. This draws attention to the urgent need for more efficient treatments. Novel anti-hepatitis C treatments under study are directed against a number of so-called direct antiviral targets such as polymerases and proteases, which are encoded by the virus. Although such direct antiviral approaches have proven to be successful in several viral indications, there is a risk of resistant viruses developing. In order to avoid resistance, the development of indirect antiviral compounds has to be intensified. These act on host cell targets either by boosting the immune response or by blocking the virus host cell interaction. A particularly interesting approach is the development of inhibitors that interfere with signal transduction, such as protein kinase inhibitors. The purpose of this review is to stress the importance of developing indirect antiviral agents that act on host cell targets. In doing so, a large source of potential targets and mechanisms can be exploited, thus increasing the likelihood of success. Ultimately, combination therapies consisting of drugs against direct and indirect viral targets will most probably provide the solution to fighting and eradicating hepatitis C virus in patients.

Current and emerging therapeutic approaches to hepatitis C infection

Hepatitis C virus is a frequent disease infecting an estimated 3% of the worlds population. It represents a major health problem and must be combated by all means. The aim of this review is to discuss the current treatment methods, including interferon-alpha, either standard or pegylated, and ribavirin. Emerging treatments will also be discussed for this potentially curable disease.

Persistent oxidative stress in patients with chronic active hepatitis-C infection after antiviral therapy failure

BACKGROUND/AIMS

Oxidative stress and hepatocellular pathological changes are common associations with chronic hepatitis C virus (CHC) disease. The aim of this study was to assess serum antioxidant-oxidant (Redox) balance in patients with CHC infection before and after intake of the traditional antiviral therapy (pegylated interferon α-2b and oral ribavirin).

PATIENTS AND METHODS

Blood samples from 50 biopsy-proven CHC patients, with no prior anti-viral treatment and persistently elevated serum transaminase levels for 6 months, as well as 15 age- and sex-matched healthy subjects were used for determination of the antioxidants: reduced glutathione (GSH), superoxide dismutase (SOD), α tocopherol and ascorbic acid as well as lipid peroxidation (LPO) index (malondialdehyde [MDA]). The measurements were repeated in the diseased group 25 weeks after pegylated interferon α-2b and ribavirin combination therapy.

RESULTS

Serum levels of bilirubin, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were significantly higher in CHC patients than in the control group (P < 0.05). Pretreatment serum MDA values were significantly higher in patients with CHC infection than the control group (P < 0.001), while serum antioxidant levels were significantly lower (P < 0.001). Responders (10 patients) had lower pretreatment serum levels of MDA than non-responders (35 patients) (P < 0.001). Both groups were comparable for the antioxidant serum levels. There was significant negative correlation between serum MDA and serum SOD, GSH, α tocopherol, and ascorbic acid concentrations in CHC patients. On the other hand, there was no correlation between the studied parameters and serum bilirubin, albumin, ALT, and AST.

CONCLUSIONS

Redox imbalance was detected in patients with CHC. Responders had significantly lower levels of MDA than non-responders. Serum MDA may be used as a pretreatment predictor of response to antiviral treatment in patients with CHC.

Novel interferons for treatment of hepatitis C virus

The current standard of care for treatment of hepatitis C is pegylated interferon and ribavirin. Despite the large number of new oral agents under development, interferon will likely remain the backbone of future therapy. Interferon has unique antiviral and immunomodulatory properties, which have been critical in limiting resistance to protease inhibitors and improving efficacy. Hence, optimizing pharmacokinetics and promoting adherence to interferon dosing regimens will become even more critical as new regimens enter the clinical arena. This review highlights novel interferons under development that may offer therapeutic advantages over the formulations currently available.

Interferon beta 1a versus interferon beta 1a plus ribavirin for the treatment of chronic hepatitis C in Chinese patients: a randomized, placebo-controlled trial

For chronic hepatitis C virus (HCV) infection, the effects of current therapies are limited. To evaluate the efficacy and safety of the interferon beta-1a (IFN beta-1a) versus IFN beta-1a plus ribavirin (RBV) combination on Chinese treatment-naïve patients with chronic hepatitis C, a randomized, placebo-controlled study was performed. A total of 26 naïve patients histologically confirmed to have chronic hepatitis C were double-blindly and randomly assigned to receive either IFN beta-1a 44 microg (12 MIU) (IFN beta-1a group) or placebo (placebo group) three times per week for 12 weeks. At the end of the 12 weeks of treatment, the patients who received IFN beta-1a continued to complete 24 weeks of treatment. Placebo non-responders were crossed over to IFN beta-1a plus RBV (1,000-1,200 mg/day) combination therapy (IFN beta-1a plus RBV group) for 24 weeks after 4 weeks washout. All patients were followed up for 24 weeks after the end of treatment. Sustained virological response (SVR) was defined as the absence of detectable HCV RNA in the serum both at the end of 24 weeks of treatment and at the end of 24 weeks of untreated follow-up. There were no differences in the clinical background between the groups before the initiation of treatment. At the end of the 12 weeks of double-blind therapy, HCV RNA was negative and undetectable in 10/11 patients (90.9%) in the IFN beta-1a group and none in the placebo group. The virological response rate (14/15, 93.3%) of the IFN beta-1a plus RBV group at week 12 after the initiation of therapy was similar to that of the IFN beta-1a group. SVR was observed in 5/11 (45.5%) of the IFN beta-1a group and 11/15 (73.3%) of the IFN beta-1a plus RBV group (P = 0.23). At the end of follow-up, a biochemical response was found in 5/11 patients in the IFN beta-1a group (45.5%) and 8/15 patients in the IFN beta-1a plus RBV group (53.3%, P = 1.00). Multiple logistic regression analysis confirmed that an HCV RNA load lower than 1.0x10(6) copies/ml was independently associated with SVR (OR 11.00; 95% CI 1.81-66.97; P = 0.003). The side effects were mild and similar in the two therapy groups. We conclude that IFN beta-1a alone or in combination with RBV provided considerable benefit in Chinese naïve patients with chronic hepatitis C. Treatments with IFN beta-1a alone or IFN beta-1a plus RBV are safe and well tolerated, and may represent an alternative for chronic hepatitis C patients who are unable to tolerate pegylated interferon alpha.

Natural human interferon beta plus ribavirin combination therapy in Japanese patients infected with hepatitis C virus and a high viral load

OBJECTIVE

The aim of this pilot study was to determine the safety and efficacy of natural human interferon beta (nIFNbeta) plus ribavirin (RBV) in patients with chronic hepatitis C who did not respond to pegylated interferon alpha (PEG-IFN), with special emphasis on the incidence of mental disorders or refusal for fear of adverse effects.

METHODS

We studied 19 patients with HCV genotype 1b, 2a or 2b and a high viral load, including 8 patients with mental disorders. They were treated with nIFNbeta-RBV. Eleven patients with HCV genotype 1b of these patients were treated with nIFNbeta-RBV for 48 weeks (group A), and compared with 22 matched controls treated with PEG-IFN plus RBV for 48 weeks (group B). The other 8 patients with HCV genotype 2 were treated with nIFNbeta-RBV for 24 weeks.

RESULTS

Six of 8 patients with mental disorders and 9 of 11 patients without mental disorders completed nIFNbeta-RBV therapy; 1 patient with mental disorder dropped out due to exacerbation of depression, and 3 patients suspended the therapy due to insufficient response. The sustained virological response (SVR) was 27% (3/11) in group A and 41% (9/22) in group B (p = 0.70). During treatment, platelet count increased in group A but not in group B. SVR was 88% (7/8) in patients of genotype 2 and high viral load treated with nIFNbeta plus RBV.

CONCLUSION

nIFNbeta-RBV therapy offers sufficient safety and efficacy for patients with mental disorders, and thus could represent an excellent second-line therapy for subpopulations that are not suitable for PEG-IFN-RBV.

Is interferon-beta an alternative treatment for chronic hepatitis C

The treatment of chronic hepatitis C (CHC) is still far from optimal, particularly for those subpopulations that do not respond to the standard combination therapy with Interferon-α (IFNα) plus ribavirin. Although in some cases the use of higher doses or longer treatment periods may be effective, these approaches are generally associated with a higher incidence of adverse events, which may either lead to a reduction in patient compliance or require drug withdrawal. IFNβ could represent an interesting alternative for treating CHC patients. Controversial data about IFNβ efficacy in CHC exist, the main reason being that many results stem from pilot studies with small cohorts of patients. However, promising results have been obtained in some subgroups of patients that fail to respond to IFNα. Additionally, the good tolerability of IFNβ represents an important advantage of the drug. The rates of dropouts in controlled clinical trials, as well as the need for dose reductions or treatment discontinuation are very low. It might be worth assessing the value of IFNβ plus ribavirin in randomized studies with a larger cohort of patients, not eligible or not tolerating standard therapy, and for non-responders.

Interferon β-1a alone or in combination with ribavirin: A randomized trial to compare efficacy and safety in chronic hepatitis C

AIM: To compare the efficacy and safety of recombinant human IFN β-1a alone or in combination with ribavirin in treatment-naïve subjects with chronic hepatitis C.

METHODS: Open, randomized trial was performed in 6 Italian tertiary centers: 102 of the 108 patients screened were randomized to receive 6 MIU of recombinant human IFN β-1a subcutaneously daily for 24 wk, alone (Group 1, n = 51) or in combination with ribavirin 1 000 to 1 200 mg/d (Group 2, n = 51).

RESULTS: The end-of-treatment virologic response rate was 29.4% in Group 1 and 41.2% in Group 2 (non-significant). Twenty-four weeks after stopping therapy, sustained virologic response rate was 21.6% in Group 1 and 27.4% in Group 2 (non-significant). All subjects in Group 1 completed treatment, while two subjects in Group 2 stopped therapy due to treatment-related adverse events.

CONCLUSION: Recombinant human IFN β-1a, alone or in combination with ribavirin, has an excellent safety profile and, may represent an alternative for chronic hepatitis C patients who are unable to tolerate pegylated α-interferon.

Safety of interferon β treatment for chronic HCV hepatitis

Hepatitis C is a major cause of liver-related morbidity and mortality worldwide. In fact, chronic hepatitis C is considered as one of the primary causes of chronic liver disease, cirrhosis and hepatocellular carcinoma, and is the most common reason for liver transplantation. The primary objectives for the treatment of HCV-related chronic hepatitis is to eradicate infection and prevent progression of the disease. The treatment has evolved from the use of α -interferon (IFNα) alone to the combination of IFNα plus ribavirin, with a significant improvement in the overall efficacy, and to the newer PEG-IFNs which have further increased the virological response, used either alone or in combination with ribavirin. Despite these positive results, in terms of efficacy, concerns are related to the safety and adverse events. Many patients must reduce the dose of PEG-IFN or ribavirin, others must stop the treatment and a variable percentage of subjects are not suitable owing to intolerance toward drugs. IFNβ represents a potential therapeutic alternative for the treatment of chronic viral hepatitis and in some countries it plays an important role in therapeutic protocols. Aim of the present paper was to review available data on the safety of IFNβ treatment in HCV-related chronic hepatitis.

The rates of treatment discontinuation and/or dose modification due to the appearance of severe side effects during IFNβ are generally low and in several clinical studies no requirements for treatment discontinuation and/or dose modifications have been reported. The most frequent side effects experienced during IFNβ treatment are flu-like syndromes, fever, fatigue and injection-site reactions. No differences in terms of side-effect frequency and severity between responders and non-responders have been reported. A more recent study, performed to compare IFNβ alone or in combination with ribavirin, confirmed the good safety profile of both treatments. Similar trends of adverse event frequency have been observed in subpopulations such as patients with genotype-1b HCV hepatitis unresponsive to IFNα treatment or with HCV-related cirrhosis and patients with acute viral hepatitis. If further studies will confirm the efficacy of combined IFNβ and ribavirin treatment, this regimen could represent a safe and alternative therapeutic option in selected patients.