Peginterferon-alfa2a plus ribavirin for 48 versus 72 weeks in patients with detectable hepatitis C virus RNA at week 4 of treatment

Interferon-based treatment of chronic hepatitis C

The treatment of patients with chronic hepatitis C has rapidly evolved in the past 10 years centered on the use of interferon alpha 2 as an antiviral and immunomodulatory agent against hepatitis C virus. Firstly used as a monotherapy associated with a deceiving long-term efficacy, interferon alpha was then combined with ribavirin, a nucleoside analog with large antiviral properties. Combination of both drugs dramatically improved the efficacy of treatment with 50% of patients reaching a sustained viral response, characterized by the final eradication of the virus from the infected individual. Surprisingly, this synergistic effect remains greatly unexplained. The third step consisted in the use of pegylated interferon in order to adapt its pharmacokinetics and to allow a better efficacy with a more tolerable dosing schedule: once weekly subcutaneous injection instead of thrice weekly. Pegylated interferon combined with ribavirin during 24-48 weeks of treatment is the current standard of care with nearly 60% of sustained virologic response, overall. Development of new forms of interferon alpha are on the way with promising preliminary results.

Update on viral hepatitis: 2006

PURPOSE OF REVIEW

This is a concise review of recent developments in the field of viral hepatitis, based on publications between December 2005 and November 2006.

RECENT FINDINGS

Elevated hepatitis B virus DNA levels in patients in their 40s with perinatally acquired hepatitis B virus infection increases the risk for cirrhosis and hepatocellular carcinoma. Six approved therapies are available for chronic hepatitis B. Entecavir is a potent antiviral for nucleoside-naïve patients. For lamivudine resistant hepatitis B virus infection, adefovir should be added to lamivudine to reduce the risk of adefovir-resistant mutations; however, tenofovir may be a more promising alternative to adefovir. A shorter duration of treatment wth pegylated interferon and ribavirin is sufficient for genotype 2 hepatitis C infection but the benefits of extending treatment to 72 weeks for genotype 1 needs to be confirmed. Pegylated interferon monotherapy was shown to be effective in patients with hepatitis D and ribavirin provides no additional benefit.

SUMMARY

New developments in the past year will help us fine tune the treatment of viral hepatitis. Even as new treatments are approved, the potential benefits of treatment should be weighed against the risk of drug-resistant mutations with long-term therapy.

Experiences on antiviral treatment for chronic viral B and C hepatitis patients in Hungary. 1998–2004

Az utolsó évtizedben számos multicentrikus, randomizált vizsgálat bizonyította az előrehaladást a krónikus vírushepatitisek kezelésében. Ugyanakkor csak korlátozott számú és ellentmondásos adatokat közöltek az antivirális terápia reális értékéről a mindennapos rutin klinikai gyakorlatában. Cél: Retrospektív felmérést végeztünk a terápia hatékonyságának megállapítására krónikus B- és C-hepatitisben, egy 7 éves periódus alatt kezelt országos populációban. Emellett bemutatjuk még egy hazai prospektív vizsgálat néhány adatát is. Módszerek: 220 krónikus B-hepatitises beteget kezeltünk, közülük 112 standard interferon-, 23 pegilált interferon-, 85 lamivudin-terápiában részesült, akikben a HbeAg-szerokonverzió és/vagy HBV-DNS-negatívvá válás arányát vizsgáltuk. A retrospektív elemzésben szereplő 2442 krónikus C-hepatitises közül 333 standard interferon-monoterápiát, 1122 standard interferon + ribavirin kombinációt és 987 pegilált interferon + ribavirin-kezelést kapott. A prospektív vizsgálatban 69 HCV1-beteg pegilált interferon α-2a + ribavirin terápiában részesült 6–12 hónapon át. A tartós virológiai válasz mellett vizsgáltuk a kedvező kimenetel prediktorait és a mellékhatások előfordulását. Eredmények: Krónikus B-hepatitisben a standard interferon 31%-os, a pegilált interferon 30%-os, a lamivudin 31–33%-os tartós vírusnegativitáshoz vezetett. Krónikus C-hepatitisben a tartós virológiai válasz aránya az interferon-monoterápiával észlelt 13%-ról a pegilált interferon + ribavirin mellett 31%-ra nőtt, a prospektív vizsgálatban ez 48% volt. A jó prognózis prediktora a rapid (4 hetes) és a korai (12 hetes) virológiai válasz, a női nem, az életkor, BMI és az adherencia volt. A betegek 9%-ában fordult elő mellékhatás, leggyakrabban cytopenia, haemolysis és depresszió. Következtetés: A krónikus B-hepatitisszel ellentétben, a hepatitis C-vírusinfekció kezelésének effektivitása hazánkban is fokozatosan javult. A mindennapi gyakorlat országos adatai azonban elmaradnak a prospektív vizsgálat sikerességétől. A jövőben hatékonyabb terápiás stratégiák szükségesek, beleértve az individualizált dozírozást és az új antivirális szerek alkalmazását.

The effects of HCV infection and management on health-related quality of life

Infection with HCV leads to an array of symptoms that compromise health-related quality of life (HRQL). Chronic hepatitis C is treated primarily with pegylated interferon (peg-IFN) and an inosine 5' monophosphate dehydrogenase inhibitor, ribavirin (RBV), with the goal of achieving a sustained virologic response (SVR). SVR reduces the rate of hepatic fibrosis and other disease-related complications and, in turn, increases HRQL. Although combination therapy with peg-IFN and RBV produces SVRs in more than 50% of treated patients, it is associated with side effects that can reduce short-term HRQL, can lead to dose reductions and discontinuations, and may impair treatment response. Fatigue and depression are common symptoms of chronic HCV infection that may also be caused by IFN-based therapy. Hemolytic anemia and IFN-mediated bone marrow suppression are well-known consequences of IFN/RBV therapy, often resulting in dose reductions or discontinuations, and have the potential to affect SVR rates. Management of these symptoms is vital to successful outcomes and generally relies on therapy that is adjunctive to the primary treatment of the viral infection itself. Several new drugs with the potential to increase SVR rates without compromising HRQL are in development.

CONCLUSION

The relationship of chronic HCV infection, treatment, and HRQL is complex. Successful treatment of chronic hepatitis C requires an understanding of the intricacies of this relationship and appropriate management of treatment-related symptoms.

Changing treatment paradigms: hepatitis C virus in HIV-infected patients

The evaluation of hepatic histology and treatment of hepatitis C virus (HCV)/HIV-coinfected patients is rapidly changing. HCV has become an important cause of mortality in HIV-infected patients. Consequently, assessment of liver histology in all coinfected patients is particularly important. The evaluation of hepatic histology is shifting from reliance on the liver biopsy toward noninvasive modalities. Additionally, the importance of HCV-associated morbidity and mortality in HIV-infected patients has prompted increasing numbers of these patients to be HCV treatment candidates. Prospective trials in coinfected patients have reported lower sustained virologic responses compared to HCV-monoinfected patients. Consequently, the numbers of coinfected nonresponders to pegylated interferon/ribavirin continues to increase. Because none of the presently available treatment modalities for pegylated interferon/ribavirin nonresponders are clearly efficacious, management decisions must be individualized. The options include, HCV-specific medications, maintenance therapy, the use of alternative interferon formulations, and observation. HCV-specific agents, particularly protease and polymerase inhibitors, show early promise in HCV-monoinfected individuals. Their use in coinfected patients, however, is likely to be delayed for several years, and they are likely to be used in combination with interferon. Low-dose pegylated interferon, administered in an attempt to slow fibrosis progression (maintenance therapy), is being evaluated in several large prospective trials in monoinfected and coinfected patients. Observation may be best for nonresponders with relatively mild hepatic histology. In summary, HCV treatment will likely follow the example forged by HIV. In the near future, combinations of different drugs will likely be used simultaneously to result in durable viral suppression.

Impact of ribavirin dose reductions in hepatitis C virus genotype 1 patients completing peginterferon alfa-2a/ribavirin treatment

BACKGROUND & AIMS

To maximize sustained virologic response (SVR) in patients with chronic hepatitis C virus (HCV) infection, treatment with pegylated interferon and ribavirin has been genotype-specific (1 vs non-1). We evaluated the effects of ribavirin and peginterferon alfa-2a dose reductions on SVR in patients infected with HCV genotype 1.

METHODS

Data were pooled from 569 patients enrolled in 2 phase III trials of 48 weeks of treatment with peginterferon alfa-2a and ribavirin. All patients were evaluated for the effect of cumulative drug exposure on 4- and 12-week responses, and the 427 patients who completed treatment were evaluated for effect of drug exposure on SVR.

RESULTS

Of patients who completed treatment, more had reductions (< or =97% cumulative dose) of ribavirin than of peginterferon alfa-2a (43% vs 27%). Neither early virologic response nor SVR was affected adversely by ribavirin reductions when the cumulative ribavirin exposure was greater than 60%. The SVR was reduced significantly (P = .0006) in patients with less than the 60% cumulative ribavirin dose and was associated with prolonged periods of dose reduction, temporary interruptions, or premature cessation of ribavirin. Ribavirin dose reductions had minimal impact on SVR in patients who achieved rapid virologic response, defined as undetectable HCV RNA levels after 4 weeks, even when they received less than the 60% cumulative ribavirin dose. In contrast, SVR was reduced markedly in patients who had ribavirin dose reductions and did not achieve rapid virologic response.

CONCLUSIONS

Minor ribavirin dose reductions to manage adverse events do not appear to affect SVR adversely, unless cumulative exposure is less than 60%. Prospective studies, however, are required to establish the impact of ribavirin dose reduction on SVR.

Customizing treatment to patient populations

Combination treatment with pegylated interferon plus ribavirin is the most effective therapy for patients with chronic hepatitis C virus (HCV); however, responses are less than optimal in some subpopulations of patients. Emerging insights are suggesting that viral kinetics can be used to predict response. The rapidity of response has been shown to be a more important predictor of sustained virologic response than the duration of therapy. In patients with HCV genotype 2 or 3, shorter durations of treatment might be sufficient in rapid responders and could minimize the risk of toxic effects. Weight-based dosing of ribavirin has emerged as another important consideration. This strategy seems to be most important for difficult-to-treat patients with HCV genotype 1 or advanced fibrosis, and for African-Americans, and is possibly important for patients who have genotype 3 and a high viral load. Re-treatment of nonresponders with interferon-based therapy has been associated with low rates of sustained virologic response. Consensus interferon might offer a new option for patients who do not achieve an early treatment response to standard or pegylated interferon plus ribavirin.

Peginterferon-α2a in the treatment of chronic hepatitis C

Chronic hepatitis C virus infection occurs worldwide and affects over 2.7 million adults in North America. Current standard of care is the combination of pegylated (peg) interferon and ribavirin for 24 weeks in hepatitis C virus genotypes 2 or 3 and at least 48 weeks in chronic hepatitis C virus infection genotypes 1 or 4. Peginterferon-α2a is a 40-kDa linear pegylated molecule that alters the pharmacokinetic properties of unmodified interferon-α. In clinical trials evaluating the combination of peginterferon-α2a and ribavirin in chronic chronic hepatitis C virus infection, sustained virologic response rates have been achieved in 46–52% of patients with genotype 1 and 76–80% of patients with genotypes 2 or 3. Studies on the role of longer treatment duration and retreatment in prior nonresponders are in progress. The main toxicities of peginterferon-α2a are flu-like symptoms and neuropsychiatric disorders, especially depression and cytopenias, and are found in similar rates to those observed with regular inteferon. Future areas of study include the role of peginterferon-α2a in combination with the newer oral chronic hepatitis C virus infection active agents in development.

Optimizing Treatment Outcomes in Chronic Hepatitis C: Management of Non-Response

The overarching goal in treating chronic hepatitis C (CHC) is the prevention of serious hepatic complications such as cirrhosis, end-stage liver disease and hepatocellular carcinoma. Successful eradication of the hepatitis C virus has been shown to prevent liver disease progression and even promote regression of fibrosis. The treatment of CHC has improved significantly over the past decade with the introduction of interferons (IFNs), and more recently, pegylated IFNs. Up to two-thirds of all patients treated with a pegylated IFN combined with ribavirin can now achieve viral eradication if treated according to current guidelines. Despite this success rate, limited treatment options currently exist for the growing number of patients who do not respond to this combination, and those who have previously failed treatment with conventional IFN-based regimens. There are numerous host-and viral-related factors that can contribute to these outcomes. In addition, treatment insufficiency, whether due to treatment type, side effects or non-compliance, can result in inadequate antiviral pressure and a reduced likelihood of response. This review explores putative management strategies for patients who have previously failed to achieve a response to IFN-based therapy, and summarises retreatment options that have been, and are currently being evaluated.

Optimizing treatment regimens in hepatitis C

Scientists and clinicians have made tremendous advances in understanding the pathogenesis of hepatitis C virus (HCV) infection and have developed impressive strategies for treating this hepatotropic virus in the short time since its discovery in 1989. This article goes beyond the current guidelines for the treatment of HCV infection to examine the use of multiple pretreatment factors to predict response; the use of viral kinetics to guide length of treatment; higher dose ribavirin in genotype 1 infection; retreatment of non responders and relapsers; and improving adherence to therapy.