Treatment of chronic hepatitis C virus genotype 1 with peginterferon, ribavirin, and epoetin alpha

Randomized trial comparing dose reduction and growth factor supplementation for management of hematological side effects in HIV/hepatitis C virus patients receiving pegylated-interferon and ribavirin

BACKGROUND

Pegylated-interferon (PEG-IFN) and ribavirin (RBV), current standard treatment for hepatitis C virus (HCV) infection, are frequently associated with neutropenia and anemia, leading to high treatment discontinuation rates in HIV/HCV-coinfected patients. Our objective was to compare the effectiveness of intervening with hematologic growth factors versus dose reductions of standard HCV therapy for the management of treatment-induced hematologic disorders.

METHODS

Ninety-two HIV/HCV-coinfected, therapy-naive subjects received PEG-IFN alfa-2b 1.5 μg·kg⁻¹·wk⁻¹ and RBV 13 ± 2 mg·kg⁻¹·d⁻¹ for up to 48 weeks. Before treatment initiation, subjects were randomized to subsequently receive growth factors, recombinant human erythropoietin (rHuEPO) and/or granulocyte colony-stimulating factor, or dose reduction (RBV and/or PEG-IFN) for anemia and neutropenia management, respectively. We analyzed the ability of each management strategy to control anemia and neutropenia and the percentage of subjects who achieved a successful treatment outcome according to the different management strategies.

RESULTS

During treatment, 43 subjects developed anemia (human erythropoietin, n = 24; dose reduction, n = 19), whereas 25 subjects developed neutropenia (granulocyte colony-stimulating factor, n = 10; dose reduction, n = 15). After the intervention, the increase in both hemoglobin and absolute neutrophil counts did not differ between the 2 side effect management strategies. Sustained response percentages were similar comparing anemic and neutropenic subjects regardless of management strategy (anemia: recombinant human erythropoietin, 29% versus dose reduction, 21%, P = 0.92; neutropenia: granulocyte colony-stimulating factor, 40% versus dose reduction, 20%, P = 0.46).

CONCLUSIONS

Growth factor supplementation and dose reduction do not seem to differ as management strategies for anemia and neutropenia in HIV/HCV-coinfected individuals treated with PEG-IFN/RBV.

Side-effects of pegylated interferon plus ribavirin therapy with or without protease inhibitor direct acting antiviral agents during treatment of chronic hepatitis C virus infection

Hepatitis C virus (HCV) infection affects 2–3% of the population, approximately 170 million people worldwide, causing chronic HCV-related hepatitis with subsequent liver cirrhosis, hepatic failure, hepatocellular cancer, and liver-related mortality in a large number of patients. The gold standard therapy, pegylated interferon alpha in combination with ribavirin can eradicate hepatitis C virus infection in approx. 40% of treatment-naïve patients infected with HCV genotype G1, and only 15–20% of patients with previous treatment. Success rate is substantially improved with the development and registration of two direct acting anti-hepatitis C virus protease inhibitors (boceprevir and telaprevir) in the second decade of 21st century: combined with the standard therapy, almost three quarter of previously untreated, and more than half of previously unsuccessfully treated patients can achieve sustained viral response with protease inhibitor based triple therapies. A major barrier to successful treatment is the association of peginterferon/ribavirin therapy with frequent and sometimes serious adverse effects. In clinical trials, approximately 10–15% of treated patients discontinue peginterferon and ribavirin due to adverse events; however, in routine clinical practice, the rate of treatment discontinuation has been reported to be substantially higher. The side effects of peginterferon/ribavirin therapy affect virtually all organ systems, and addition of protease inhibitor can amplify these side effects (particularly anemia), and/or may lead to new ones (i.e., dysgeusia with boceprevir or skin rush with telaprevir). There is considerable regional and global variability in the nature and prevalence of these adverse effects as well as in the best strategies to ameliorate their impact on hepatitis C virus treatment. This article summarizes the side effects of dual and triple therapies and their management based on the labels of the drugs, on a comprehensive literature review, as well as on the recently published opinion of an international panel of experts – with the provision of providing help for the physicians treating hepatitis C virus infection to achieve the best possible success with the highest possible safety for the patients. Orv. Hetil., 2011, 152, 1997–2009.

Pharmacological exposure to ribavirin: a key player in the complex network of factors implicated in virological response and anaemia in hepatitis C treatment

Ribavirin remains today a pivotal drug in the treatment of hepatitis C; in standard double therapy, as well as in triple combination with direct antiviral agents, ribavirin reduces relapse and can double the sustained virological response obtained with peginterferon alone or in association with direct antiviral agents. In the complex network of interacting factors determining sustained virological response independently of known predictive factors related to host and virus, two modern tools are emerging: polymorphisms in the IL28B gene and very early exposure to ribavirin. The use of a pharmacokinetic-pharmacodynamic model of early ribavirin exposure to adjust the dose individually would help promote a safer ribavirin use and improve sustained virological response. The variability of the influence of ribavirin exposure on anaemia is probably genetically determined; however, the low prevalence of the implicated protective alleles of the inosine triphosphate pyrophosphatase gene could explain their lack of influence on sustained virological response.

Cyclosporine a-based immunosuppression reduces relapse rate after antiviral therapy in transplanted patients with hepatitis C virus infection: a large multicenter cohort study

BACKGROUND

The influence of immunosuppression on the response to antiviral treatment in recurrent hepatitis C is still under debate. The purpose of this study was to identify those factors that might predict sustained viral response and relapse.

METHODS

The ReViS-TC, a multicenter cohort study conducted in 14 Spanish liver centers, included data from liver transplant recipients from January 2000 to December 2006 who had recurrent hepatitis C virus and who had undergone antiviral treatment with pegylated interferon plus ribavirin. Sustained virological response (SVR) and viral relapse were evaluated. A multivariate logistic regression model was used to investigate host, donor, and therapeutic factors associated with SVR and relapse.

RESULTS

The analysis included 410 patients, 30% treated with cyclosporine A (CsA) and 70% with tacrolimus. SVR was achieved in 48% of patients with CsA and in 37% with tacrolimus (P=0.037), with a relapse rate of 18% and 36%, respectively (P=0.008). In the multivariate model, the administration of CsA (odds ratio [OR] 0.37, P=0.021) in conjunction with a longer antiviral treatment duration (OR 0.86, P=0.024) correlated with lower relapse rate, whereas the older age of the donor (OR 1.03, P=0.006) and the presence of genotype 1 (OR 3.45, P=0.032) were associated with a higher probability of relapse.

CONCLUSIONS

Our results suggest that the use of CsA-based immunosuppression regimens and longer treatment duration may protect patients against viral relapse after a positive response to pegylated interferon plus ribavirin therapy. These data need to be further confirmed in clinical trials.

Reduced dose and duration of peginterferon alfa-2b and weight-based ribavirin in patients with genotype 2 and 3 chronic hepatitis C

BACKGROUND & AIMS

There is increasing interest in identifying patients with chronic hepatitis C genotype 2 or 3 infection in whom it is possible to lower the burden of therapy while retaining high levels of efficacy.

METHODS

Treatment-naive patients with chronic hepatitis C genotype 2/3 infection were randomized to receive peginterferon alfa-2b (1.5μg/kg/wk) for 24weeks (group A); peginterferon alfa-2b (1.0μg/kg/wk) for 24weeks (group B); or peginterferon alfa-2b (1.5μg/kg/wk) for 16weeks (group C), each in combination with weight-based ribavirin (800-1200mg/d). The study population comprised two cohorts: the Hep-Net cohort enrolled in Germany and an International cohort enrolled at study sites throughout Europe and Asia. The primary end point was sustained virological response (SVR).

RESULTS

The study included 682 patients; 80.2% had genotype 3 infection. In the intent-to-treat population, SVR rates were 66.5%, 64.3%, and 56.6% in groups A, B, and C, and were similar in Asian and white patients. Treatment differences (A vs. B and A vs. C) failed to reach the predefined margin for noninferiority of -10%; and thus groups B and C failed to show noninferiority relative to group A. Among patients with undetectable HCV RNA at week 4, SVR rates were 75.3%, 75.9%, and 72.4%, respectively. Relapse rates were 17.8%, 16.3%, and 29.3%, respectively. Treatment-emergent serious adverse events were highest in group A and lowest in group C, and adverse events leading to discontinuation were similar across treatment arms.

CONCLUSIONS

For patients with chronic hepatitis C genotype 2/3 infection, 24weeks of peginterferon alfa-2b (1.5μg/kg/wk) plus weight-based ribavirin remains a standard-of-care therapy; however, treatment for 16weeks may be considered for patients with undetectable HCV RNA at week 4 of the treatment.

Anti-viral therapy in haemodialysed HCV patients: efficacy, tolerance and treatment strategy

BACKGROUND

In end-stage renal disease (ESRD) patients, hepatitis C virus (HCV) eradication improves patient and graft survival.

AIM

To determine optimal use of erythropoietin (EPO) and ribavirin, to compare ribavirin concentrations with those of HCV patients having normal renal function and to evaluate sustained virological response (SVR) in a prospective observatory of ESRD candidates for renal transplantation.

METHODS

Thirty-two naïve patients were treated with Peg-IFN-α2a and ribavirin. Two different schedules of ribavirin and EPO administration were used: starting ribavirin at 600mg per week and adapting EPO when haemoglobin (Hb) fell below 10g/dL (adaptive strategy) or starting ribavirin at 1000mg per week while increasing EPO from the start of treatment (preventive strategy).

RESULTS

Patients treated with the adaptive strategy had lower median Hb levels (9.6 vs. 10.9g/dL, P=0.02) and more frequent median Hb levels below 10g/dL (58 vs. 5%, P=0.0007) despite lower median ribavirin doses (105 vs. 142mg/day, P<0.0001) than patients treated with the preventive strategy. There was a trend for more frequent transfusion in patients treated with the adaptive strategy than in patients treated with preventive strategy (50 vs. 20%, P=0.08). Compared to patients with normal renal function, ESRD patients had lower ribavirin concentrations during the first month (0.81 vs. 1.7mg/L, P=0.007) and similar concentrations thereafter. SVR was reached in 50%.

CONCLUSIONS

Pegylated interferon (Peg-IFN) and an adapted schedule of ribavirin are effective in ESRD patients. Increasing EPO from the start of treatment provides better haematological tolerance. The optimal dosage of ribavirin remains unresolved, in light of frequent side effects.

Impact of ribavirin dose reduction on the efficacy of pegylated interferon plus ribavirin combination therapy for elderly patients infected with genotype 1b and high viral loads

AIM

  To examine the impact of ribavirin dose reduction on the efficacy of pegylated interferon (PEG IFN) plus ribavirin combination therapy for elderly patients infected with genotype 1b and high viral loads.

METHODS

  A total of 72 patients, over 65 years old, were recruited for this study. Patients were divided into groups receiving either 600-800 mg of ribavirin according to bodyweight (Group 1, n = 36) or 400 mg of ribavirin (Group 2, n = 36) plus 1.5 µg/kg (range: 1.3-2.0 µg/kg) of PEG IFN-α-2b for 48 weeks.

RESULTS

  Total ribavirin doses were administrated at 9.80 ± 2.39 mg/kg per day (3.29 ± 0.80 g/kg) for Group 1 and 5.87 ± 1.82 mg/kg per day (1.97 ± 0.61 g/kg) for Group 2 (P < 0.001). According to the total clearance (CL/F) of ribavirin, 34 of 36 patients in Group 1 received over-doses of ribavirin. In contrast, numbers of those receiving equivalent doses of ribavirin were two of 36 patients in Group 1 and 36 of 36 patients in Group 2, respectively (P < 0.001). End-of-treatment response (ETR) rates were observed in 23 of 36 patients (63.9%) in the standard ribavirin dose protocol and in 23 of 36 patients (63.9%) in the reduction ribavirin dose protocol (NS). Sustained virological response (SVR) rates were observed in 11 of 36 patients (30.6%) in the standard ribavirin dose protocol, and in 13 of 36 patients (36.1%) in the reduced ribavirin dose protocol (NS).

CONCLUSION

  Reduction of ribavirin doses for elderly patients did not affect the outcome for the 48-week combination therapy.

Chronic hepatitis C

The goal of antiviral therapy for patients with chronic hepatitis C virus (HCV) infection is to attain a sustained virologic response (SVR), which is defined as undetectable serum HCV-RNA levels at 6 months after the cessation of treatment. Major improvements in antiviral therapy for chronic hepatitis C have occurred in the past decade. The addition of ribavirin to interferon-alfa therapy and the introduction of pegylated interferon (PEG-IFN) have substantially improved SVR rates in patients with chronic hepatitis C. The optimization of HCV therapy with PEG-IFN and ribavirin continues to evolve. Studies are ongoing that use viral kinetics to tailor therapy to an individual's antiviral response and determine the ideal length of treatment to maximize the chance of SVR. Improved SVR can be achieved with new specific inhibitors that target the HCV NS3/4A protease and the NS5B polymerase. Several long-term follow-up studies have shown that SVR, when achieved, is associated with a very low risk of virologic relapse. Furthermore, antiviral therapy can reduce the morbidity and mortality rates associated with chronic hepatitis C by reducing fibrosis progression, the incidence of cirrhosis, and hepatocellular carcinoma.

Management of adverse effects of Peg-IFN and ribavirin therapy for hepatitis C

HCV infects approximately 2-3% of the global population and is a leading cause of end-stage liver disease and hepatocellular carcinoma. Treatment of HCV infection with Peg-IFN in combination with ribavirin can eradicate HCV infection in 40-90% of patients; however, a major barrier to treatment uptake and delivery is the association of this therapy with frequent and, at times, serious adverse effects. Recognition and effective management of these adverse effects are critical components of the successful treatment of chronic HCV infection. In clinical trials, approximately 10-15% of patients discontinue Peg-IFN and ribavirin therapy due to adverse effects; however, in clinical practice, the rate of treatment discontinuation has been reported to be substantially higher. The off-target effect of Peg-IFN and ribavirin impacts most, if not all, organ systems; the most common adverse effects are hematologic, dermatologic, neurologic, immunologic, gastrointestinal, pulmonary, cardiovascular, and ocular. Regional and global variability exists in the nature of these adverse effects and the strategies employed to ameliorate their impact. This article provides a comprehensive literature review that systematically describes the adverse effects of Peg-IFN-α and ribavirin on various organ systems and, more importantly, recommends consensus approaches to managing those effects.

Evaluation of early null response to pegylated interferon and ribavirin as a predictor of therapeutic nonresponse in patients undergoing treatment for chronic hepatitis C

OBJECTIVES

Early viral kinetics accurately predicts sustained virological response (SVR) in genotype 1 patients with hepatitis C virus (HCV) undergoing therapy with pegylated interferon (PEG) and ribavirin (RBV). No baseline factor has a stronger predictive role. Early identification of patients unlikely to respond is equally important, allowing early treatment modification or discontinuation. The aim of this study was to determine whether 4-week null response (eNR) correlates directly with 12-week null response and inversely with SVR.

METHODS

A retrospective analysis of HCV patients treated at our institution was done. Patients were classified based on a 4-week viral log decline compared with baseline: <1 log, ≥ 1 log, <2 log, ≥ 2 log, <3 log, ≥ 3 log without rapid virological response (RVR) and with RVR. eNR was defined as less than a 1 log change from baseline.

RESULTS

A total of 159 patients had quantitative HCV-RNA PCR at treatment week 4, of whom 24% (38) experienced eNR. In all, 22 (58%) of the eNR patients were African American, 58% male, 32% cirrhotic, average age 53 years (range 36-71), 89% (33) genotype 1, and average baseline viral load was 5.9261 log (range 3.1492-7.3025). On-treatment response demonstrated failure to attain early virological response (EVR; 2-log decline at week 12) in 50% (19) and partial EVR (pEVR) in 39% (15). Three (8%) patients with eNR achieved SVR. In our patient population, eNR had 92% negative predictive value (confidence interval 83.5-100%) for SVR and was the strongest single predictor for treatment failure, including the baseline factors genotype and viral load.

CONCLUSIONS

eNR is strongly associated with null response or pEVR and accurately predicts failure to attain SVR. Consideration should be made to discontinue or modify therapy in patients with eNR who receive the appropriate weight-based PEG/RBV.

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'.

Ribavirin-induced anemia in hepatitis C virus patients undergoing combination therapy

The current standard of care for hepatitis C virus (HCV) infection – combination therapy with pegylated interferon and ribavirin – elicits sustained responses in only ∼50% of the patients treated. No alternatives exist for patients who do not respond to combination therapy. Addition of ribavirin substantially improves response rates to interferon and lowers relapse rates following the cessation of therapy, suggesting that increasing ribavirin exposure may further improve treatment response. A key limitation, however, is the toxic side-effect of ribavirin, hemolytic anemia, which often necessitates a reduction of ribavirin dosage and compromises treatment response. Maximizing treatment response thus requires striking a balance between the antiviral and hemolytic activities of ribavirin. Current models of viral kinetics describe the enhancement of treatment response due to ribavirin. Ribavirin-induced anemia, however, remains poorly understood and precludes rational optimization of combination therapy. Here, we develop a new mathematical model of the population dynamics of erythrocytes that quantitatively describes ribavirin-induced anemia in HCV patients. Based on the assumption that ribavirin accumulation decreases erythrocyte lifespan in a dose-dependent manner, model predictions capture several independent experimental observations of the accumulation of ribavirin in erythrocytes and the resulting decline of hemoglobin in HCV patients undergoing combination therapy, estimate the reduced erythrocyte lifespan during therapy, and describe inter-patient variations in the severity of ribavirin-induced anemia. Further, model predictions estimate the threshold ribavirin exposure beyond which anemia becomes intolerable and suggest guidelines for the usage of growth hormones, such as erythropoietin, that stimulate erythrocyte production and avert the reduction of ribavirin dosage, thereby improving treatment response. Our model thus facilitates, in conjunction with models of viral kinetics, the rational identification of treatment protocols that maximize treatment response while curtailing side effects.

The treatment of HCV infection poses a major global health-care challenge today. The current standard of care, combination therapy with interferon and ribavirin, works in only about half of the patients treated. Because no alternatives are available yet for patients in whom combination therapy fails, identifying ways to improve response to combination therapy is critical. Increasing exposure to ribavirin does improve response but is associated with the severe side-effect, anemia. One way to maximize treatment response therefore is to increase ribavirin exposure to levels just below where anemia becomes intolerable. A second way is to supplement combination therapy with growth hormones, such as erythropoietin, that increase the production of red blood cells (erythrocytes) and compensate for ribavirin-induced anemia. Rational optimization of combination therapy thus relies on a quantitative description of ribavirin-induced anemia, which is currently lacking. Here, we develop a model of the population dynamics of erythrocytes in individuals exposed to ribavirin that quantitatively describes ribavirin-induced anemia. Model predictions capture several independent observations of ribavirin-induced anemia in HCV patients undergoing combination therapy, estimate the threshold ribavirin exposure beyond which anemia becomes intolerable, suggest guidelines for the usage of growth hormones, and facilitate rational optimization of therapy.

Taribavirin: potential future in the treatment of hepatitis C

Taribavirin is a prodrug of ribavirin, studied as a treatment modality in combination with PEGylated interferon for chronic hepatitis C. Taribavirin is catalyzed to ribavirin by adenosine deaminase, which is ubiquitous within the body. Taribavirin has resulted in significantly lower rates of anemia, the main complication of ribavirin and cause of dose reductions or discontinuation. Previous clinical studies failed to demonstrate noninferiority to ribavirin. However, better results were observed when taribavirin was given as a weight-based medicine, as shown in a recently published Phase IIb study.

Pegylated interferon plus optimized weight-based ribavirin dosing negate the influence of weight and body mass index on early viral kinetics and sustained virological response in chronic hepatitis C

AIM

Elevated body mass index (BMI) in chronic hepatitis C (CHC) has been associated with reduced rates of sustained virological response (SVR). The aims of this study were to determine whether early viral kinetics (and subsequently SVR) are influenced by weight or BMI by measuring HCV RNA at week 4 using two PCR assays with differing sensitivities.

METHODS

Patients with CHC treated with peginterferon plus weight-based ribavirin were included in this retrospective study. Body mass index, pretreatment viral load, genotype and liver histology were abstracted from the clinical database. HCV RNA PCR (lower limit of detection (LLD) <50 IU/mL) at treatment week 4 and 6 months after completion of therapy were recorded to determine the presence of rapid virological response (RVR-50) and SVR, respectively. In those who achieved RVR-50, stored week 4 serum was retested using Taqman (LLD < 15 IU/mL, RVR-15).

RESULTS

Of 134 patients included (genotype 1 57%, BMI 26.7 ± 4.5 kg/m², ribavirin dose 13.9 ± 2.6 mg/kg/day), 59% achieved SVR. RVR-50 was observed in 39.6% and RVR-15 in 27.6%. Neither body weight nor BMI influenced RVR-50, RVR-15 or SVR. The positive predictive values (PPVs) of RVR-50 and RVR-15 for SVR were 88.7% and 97.3% (P = 0.23). RVR-50 and RVR-15 superceded genotype and viral load as the strongest independent predictors of SVR (OR 9.25 (1.9-45.11) and OR 30.74 (3.08-317.96), respectively).

CONCLUSIONS

RVR is the strongest predictor of SVR. Early viral kinetics is not influenced by body weight or BMI when weight-based ribavirin is prescribed.

Hepatitis C virus treatment-related anemia is associated with higher sustained virologic response rate

BACKGROUND & AIMS

Hepatitis C virus (HCV) treatment is frequently complicated by anemia from ribavirin (RBV)-related hemolysis and peginterferon-alfa (PEG-IFN)-related bone marrow suppression. We investigated the relationships among treatment outcomes, anemia, and their management with RBV dose reduction and/or erythropoiesis-stimulating agents (ESAs).

METHODS

We analyzed data from a trial conducted at 118 United States academic and community centers in treatment-naïve patients with HCV genotype 1. Patients were treated for as many as 48 weeks with 1 of 3 PEG-IFN/RBV regimens. ESAs were permitted for anemic patients (hemoglobin [Hb] <10 g/dL) after RBV dose reduction. Sustained virologic responses (SVR) were assessed based on decreases in Hb, anemia, and ESA use.

RESULTS

While patients received treatment, 3023 had their Hb levels measured at least once. An SVR was associated with the magnitude of Hb decrease: >3 g/dL, 43.7%; ≤3 g/dL, 29.9% (P < .001). Anemia occurred in 865 patients (28.6%); 449 of these (51.9%) used ESAs. In patients with early-onset anemia (≤ 8 weeks of treatment), ESAs were associated with higher SVR rate (45.0% vs 25.9%; P < .001) and reduced discontinuation of treatment because of adverse events (12.6% vs 30.1%, P < .001). ESAs did not affect SVR or discontinuation rates among patients with late-stage anemia.

CONCLUSIONS

Among HCV genotype 1-infected patients treated with PEG-IFN/RBV, anemia was associated with higher rates of SVR. The effect of ESAs varied by time to anemia; patients with early-onset anemia had higher rates of SVR with ESA use, whereas no effect was observed in those with late-onset anemia. Prospective trials are needed to assess the role of ESAs in HCV treatment.

Suboptimal endogenous erythropoietin response in chronic hepatitis C patients during ribavirin and PEG interferon treatment

BACKGROUND

During the treatment of hepatitis C, anaemia may necessitate pegylated-interferon and ribavirin dose reductions with reduced sustained viral response rates. Although erythropoietic growth factors are frequently used to improve anaemia, it is controversial whether endogenous erythropoietic response is insufficient under these circumstances. We aimed to identify risk factors for more pronounced anaemia and to evaluate endogenous erythropoietic response during antiviral therapy.

METHODS

One hundred and forty-five naive chronic hepatitis C patients on pegylated-interferon-ribavirin treatment were evaluated for haemoglobin, haematocrit, serum ribavirin and erythropoietin levels.

RESULTS

About 99% of patients developed anaemia, with maximal decrease in haemoglobin of 2.5 ± 1.0 mmol/l (range 0.3-5.5 mmol/l). Older age, lower baseline creatinine clearance, higher baseline haemoglobin, more pronounced haemoglobin decrease after 2 weeks and higher week 24 serum ribavirin concentrations were independent risk factors for more pronounced anaemia. Serum erythropoietin levels increased from median 12 IU/l (range 4-63 IU/l) at baseline to 41 IU/l (range 12-683 IU/l) after 12 weeks of therapy and to 43 IU/l (range 7-3238 IU/l) at week 24 (P<0.001). Erythropoietin levels at baseline, week 12 and week 24 negatively correlated with haematocrit. The erythropoietic response to anaemia in our study population was significantly different from the normal human response to anaemia.

CONCLUSION

Older age, lower baseline creatinine clearance, higher baseline haemoglobin, more pronounced haemoglobin decrease after 2 weeks and higher week 24 serum ribavirin concentrations were independent risk factors for more pronounced anaemia during antiviral therapy. Endogenous erythropoietin production is suboptimal during antiviral therapy, supporting use of erythropoietic growth factors.

Evolution of interferon-based therapy for chronic hepatitis C

Since 1986, interferon-alfa (IFN-α) monotherapy has been administered for patients with chronic hepatitis C (CHC). However, sustained response rate is only about 8% to 9%. Subsequent introduction of ribavirin in combination with IFN-α was a major breakthrough in the treatment of CHC. Sustained virological responses (SVRs) rate is about 30% in hepatitis C virus genotype 1 (HCV-1) patients, and is about 65% in HCV-2 or -3 patients. After 2000, pegylated interferon (PegIFN) much improved the rates of SVR. Presently, PegIFN-α-ribavirin combination therapy has been current standard of care for patients infected with HCV. In patients with HCV-1, treatment for 48 weeks is optimal, but 24 weeks of treatment is sufficient in HCV-2 or -3 infected patients. Clinical factors have been identified as predictors for the efficacy of the IFN-based therapy. The baseline factor most strongly predictive of an SVR is the presence of HCV-2 or -3 infections. Rapid virological response (RVR) is the single best predictor of an SVR to PegIFN-ribavirin therapy. If patients can't achieve a RVR but achieve a complete early virological response (cEVR), treatment with current standard of care can provide more than 90% SVR rate. HCV-1 patients who do not achieve an EVR should discontinue the therapy. Recent advances of protease inhibitor may contribute the development of a novel triple combination therapy.

Variants in the ITPA gene protect against ribavirin-induced hemolytic anemia and decrease the need for ribavirin dose reduction

BACKGROUND & AIMS

In a genome-wide association study of patients being treated for chronic hepatitis C, 2 functional variants in ITPA that cause inosine triphosphatase (ITPase) deficiency were shown to protect against ribavirin (RBV)-induced hemolytic anemia during early stages of treatment. We aimed to replicate this finding in an independent cohort from the Study of Viral Resistance to Antiviral Therapy of Chronic Hepatitis C and to investigate the effects of these variants beyond week 4.

METHODS

Genetic material was available from 318 patients. The ITPA variants, rs1127354 (exon 2, P32T) and rs7270101 (intron 2, splice altering), were genotyped and tested for association with hemoglobin (Hb) reduction at week 4. An ITPase deficiency variable was defined that combined both ITPA variants according to documented effect on ITPase activity. We investigated the impact of ITPA variants on Hb levels over the course of therapy and on the need for RBV dose reduction.

RESULTS

The final analysis included 304 patients with genotype 1 hepatitis C virus (167 white patients and 137 black patients). The polymorphisms rs1127354 and rs7270101 were associated with Hb reduction at week 4 (P = 3.1 × 10(-13) and 1.3 × 10(-3), respectively). The minor alleles of each variant protected against Hb reduction. Combining the variants into the ITPase deficiency variable strengthened the association (P = 2.4 × 10(-18)). The ITPase deficiency variable was associated with lower rates of anemia over the entire treatment period (48 weeks), as well as a lower rate of anemia-related RBV dose reduction (hazard ratio, 0.52; P = .0037). No association with sustained virological response was observed.

CONCLUSIONS

Two polymorphisms that cause ITPase deficiency are strongly associated with protection from RBV-induced hemolytic anemia and decrease the need for RBV dose reduction.

Virologic response rates of weight-based taribavirin versus ribavirin in treatment-naive patients with genotype 1 chronic hepatitis C

Ribavirin-induced hemolytic anemia can prompt dose reductions and lower sustained virologic response (SVR) rates in the treatment of patients with chronic hepatitis C. The study aimed to determine if weight-based dosing of taribavirin (TBV), an oral prodrug of ribavirin (RBV), demonstrated efficacy comparable to RBV while maintaining its previously demonstrated anemia advantage with fixed dose administration. A U.S. phase 2b randomized, open-label, active-controlled, parallel-group study was conducted in 278 treatment-naive patients infected with genotype 1 who were stratified by body weight and baseline viral load. Patients were randomized 1:1:1:1 to receive TBV (20, 25, or 30 mg/kg/day) or RBV (800-1400 mg/day) with pegylated interferon alfa-2b for 48 weeks. The SVR rates in this difficult-to-cure patient demographics (mean age, 49 years; 61% male; 30% African American or Latino; high viral load; advanced fibrosis; and mean weight, 82 kg) were 28.4%, 24.3%, 20.6%, and 21.4% in the 20, 25, and 30 mg/kg TBV groups and the RBV group, respectively. There were no statistical differences in the efficacy analyses. Anemia rates were significantly lower (P < 0.05) in the 20 and 25 mg/kg/day TBV treatment groups (13.4% and 15.7%, respectively) compared to RBV (32.9%). The most common adverse events in all groups were fatigue, diarrhea, and insomnia. Diarrhea, reported in 38% of TBV patients versus 21% of RBV patients, was generally mild and not dose-limiting.

CONCLUSION

All TBV doses demonstrated efficacy and tolerability comparable to that of RBV; however, the 25 mg/kg dose demonstrated the optimal balance of safety and efficacy. Anemia rates were significantly lower for TBV given at 20-25 mg/kg than RBV. These data suggest weight-based dosing with TBV provides a safe and effective treatment alternative to RBV for chronic hepatitis C. American Association for the Study of Liver Diseases.

Management of posttransplant hepatitis C infection

PURPOSE OF REVIEW

Chronic hepatitis C virus (HCV) infection is the leading cause of liver transplantation. Outcome of HCV-associated liver transplantation has been worse than transplantation from other causes. This is mostly related to universal recurrence of HCV in the allograft leading to graft and patient loss or retransplantation. Current antiviral therapies (AVTs) are inadequate and ineffective in the vast majority of the patients with intolerable side effects in most. However, a sustained virologic response (SVR) is associated with improved graft and patient survival. New specifically targeted AVTs for HCV (STAT-C) agents in development will significantly improve the success of AVT. This review focuses on recent data in peritransplant management of HCV with special emphasis on predictors of outcome, diagnosis, prevention and control of reinfection with newer treatments on the horizon.

RECENT FINDINGS

In the immediate pretransplant setting, AVT should be considered in select patients to eradicate the virus. Careful donor selection, immunosuppression (IMS) modulation with steroid and calcineurin inhibitor (CNI) minimization, avoidance of T-cell-depleting treatments and acute rejection episodes, and control of metabolic syndrome can improve allograft outcomes and improve the response to AVT. AVT prior to significant damage to the allograft is strongly recommended.

SUMMARY

With modified novel IMS protocols, careful donor selection, and AVT prior to significant damage to the allograft we can improve the outcome of posttransplant hepatitis C infection. Albeit there are no available data on new antiviral agents, STAT-Cs will have a significant impact in this setting in the near future.

Differential impact of adherence to pegylated interferon and ribavirin in the treatment of genotype 1 high viral titer chronic hepatitis C

To clarify the impact of adherence, we treated 122 genotype 1 high viral titer chronic hepatitis C patients with pegylated interferon (peg-IFN) and ribavirin for 48 weeks at nine referral hospitals, and evaluated the prognostic factors with a focus on the adherence to the treatment. This study included 68 (55.7%) treatment-naïve patients and 54 (44.3%) patients who did not respond to the previous treatment. Multivariate analysis revealed adherence to peg-IFN and ribavirin as the only significant predictor. Sustained virological response (SVR) rate was 72.2%, 19.0%, and 27.3% in patients given ≥80%, 60%–80%, and <60% dose peg-IFN, respectively, and was 68.6%, 41.2%, and 5.3% in those given ≥80%, 60%–80%, and <60% dose ribavirin, respectively. SVR rate sharply fell when exposure to peg-IFN was below 80% whereas it decreased in a stepwise manner as for ribavirin. Therefore, ≥80% of peg-IFN and as much as possible dose of ribavirin are desired to achieve SVR in the treatment of genotype 1 high viral titer chronic hepatitis C.

Epoetin alpha improves the response to antiviral treatment in HCV-related chronic hepatitis

BACKGROUND

The conventional antiviral treatment of chronic hepatitis related to hepatitis C virus (HCV) often leads to anemia. In this case, it is necessary to reduce ribavirin dose or stop treatment, thus reducing the rate of sustained virological response.

AIM

We investigated whether epoetin alpha administration improves treatment adherence and leads to higher percentage of response at the end of therapy and sustained virological response.

METHODS

Two hundred and fourteen individuals with genotype 1b HCV-related chronic hepatitis underwent treatment with pegylated (peg)-interferon alpha-2A 180 μg once weekly and ribavirin 1,000-1,200 mg/day; 174 were responders. Forty individuals completed treatment with no hemoglobin reduction; 134 developed anemia during therapy. Anemic responders were distributed randomly into two groups: group 1 continued therapy with epoetin alpha addiction; group 2 continued antiviral therapy with ribavirin reduction only.

RESULTS

Patients in group 1 achieved better control of hemoglobin levels (13.8 ± 1.2 g/dl at the end of therapy) than those in group 2 (11.5 ± 0.8 g/dl). Sustained virological response was 59.7% in group 1 compared with 34.4% in group 2 (p<0.01).

CONCLUSIONS

In patients with 1b HCV-related chronic hepatitis who develop anemia during antiviral treatment, administration of epoetin alpha increases hemoglobin levels and the end-of-treatment rate and sustains virological response by improving treatment adherence.

Pegylated-interferon plus ribavirin therapy in the treatment of CHC: individualization of treatment duration according to on-treatment virologic response

BACKGROUND

Standard treatment of chronic hepatitis C (CHC) is peginterferon alfa (PEG-IFN alfa) plus ribavirin (RBV) for 48 weeks in patients infected with genotype 1, and 24 weeks for those infected with genotype 2 or 3. However, recent studies have shown that on-treatment markers of virologic response can be used to tailor treatment duration according to each patient's response to therapy.

AIM

To discuss the rationale for assessing on-treatment markers of virologic response to PEG-IFN alfa plus RBV.

METHODS

A literature search was conducted using MEDLINE and conference proceedings for clinical studies of reduced and extended treatment durations in the treatment of CHC.

FINDINGS

Patients infected with genotype 1 and low baseline viral load who have undetectable HCV RNA by week 4 can be effectively treated for 24 weeks without any decline in efficacy. Extended treatment duration of 72 weeks has been studied in various selected patient groups with genotype 1 infection who are slow to respond to treatment; however, data are conflicting regarding the patient subgroup that may benefit most from this strategy. Finally, selected HCV genotype 2 or 3 patients with undetectable HCV RNA at week 4 and other favorable prognostic features may be effectively managed with shorter (12 to 16 weeks) treatment duration. Further work is required to determine how the findings of this review relate to patients who do not fit with the enrollment criteria of randomized clinical trials or who require dose adjustment based on adverse tolerability. Care should also be exercised when comparing data between studies because of differences in design and patient populations.

CONCLUSION

Evaluation of on-treatment markers of virologic response has revolutionized the treatment of CHC: implementation of these assessments in clinical practice is strongly supported by data from recent clinical studies, even in advance of formal recognition in treatment guidelines.

Pegylated Interferon and Ribavirin Dosing Strategies to Enhance Sustained Virologic Response

Hepatitis C virus (HCV) affects about 170 million people worldwide and is the most common chronic blood borne infection in the United States. Since the advent of blood screening protocols in the early 1990s, injection drug use has become the leading cause of infection. Hepatitis C can have both hepatic and nonhepatic manifestations of infection. Hepatic manifestations include hepatic fibrosis, cirrhosis, liver cancer, and liver failure. The standard treatment for chronic HCV is combination therapy with pegylated interferon-α and ribavirin. Although pegylated interferon and ribavirin has been used against HCV for close to a decade, advances in therapy have centered on doses and treatment durations. There has been increasing interest in applying on-treatment response or viral kinetics to predict antiviral response rates and shape therapeutic intervention. Protease inhibitors are a promising adjuvant to combination therapy, but their efficacy and safety are still under investigation.

Management of nonresponsive hepatitis C

More than 50% of hepatitis C virus (HCV)-infected patients do not respond to the classical pegylated interferon (PEG-IFN)/ribavirin combination therapy. However, failing to respond to one course of treatment is not synonymous of therapy failure and retreatment is often beneficial. Alternative retreatment strategies include repeating the classical standard of care with an optimized drug regimen and adherence, including ribavirin serum concentration adjustment, correcting, if at all possible, comorbidities, and the addition of new specific anti-HCV molecules to the backbone of pegylated interferon/ribavirin. Options of retreatment should include consensus and natural interferons. For patients with advanced disease exposed to a high risk of lethal complications, customized maintenance therapy could be an effective option since it may slow down complications in some patients. Since low-dose interferon monotherapy is not sufficient, such a maintenance therapy remains to be verified via clinical trials. New possibilities of noninvasive assessment of fibrosis and the use of genetic tests to predict fibrosis progression and responsiveness to interferon are major emerging opportunities that run parallel to the revolution of the pharmacologic armentarium.

Adjuvant therapy used in conjunction with combination therapy for chronic hepatitis C improves sustained virus response rates in genotype 1 patients

Combination treatment with pegylated interferon (Peg-IFN) and ribavirin remains the gold standard in the treatment of chronic hepatitis C. This therapy is limited by many side-effects including anaemia, neutropenia and reduced quality of life. The use of adjuvant agents to reduce the frequency of dose reductions because of haematological side-effects has been proven to be effective but there are few reports of what effect the use of these adjuvant therapies is having on sustained virological response (SVR). The aim of the study was to assess the clinical impact on sustained virological response of adjuvant therapies during combination therapy with Peg-IFN and ribavirin for chronic hepatitis C. A total of 132 patients, 96 males, were included in the study. The overall SVR was 66.7%, with 50% of genotype 1/4/6 (n = 27/54) patients achieving SVR and 78.2% of genotypes 2/3. The overall SVR of the treatment naïve patients (83/121) was 68.6%. Fifty-one of these patients were genotype 1 with 49.0% (25/51) of this group achieving SVR. The genotype 2/3 group of treatment naïve patients reached an SVR of 82.9% (58/70). Adjuvant therapy was used in 57 patients (43.8%). With the use of supportive adjuvant therapy, we achieved an overall SVR of 66.7% and in treatment naïve patients 68.6%. In genotype 1 patients, SVR rates of up to 46% have been reported in previous studies without the use of erythropoietin and granulocyte colony stimulating factor. We have demonstrated the SVR for genotype 1 can be improved to 50% overall.

Adverse effects of drugs in the treatment of viral hepatitis

The hepatitis B virus (HBV) and the hepatitis C virus (HCV) affect approximately 400-500 million individuals worldwide. Both infections are characterised by a significant morbidity and mortality: chronic hepatitis B and C may evolve towards the development of cirrhosis and primary hepatocellular carcinoma. During the last two decades, several new antivirals have been developed that are active against HBV and HCV, allowing sustained cure rates in a significant proportion of patients. All these drugs have side effects, which may represent a major barrier to achieve cure in many patients in need. I will review the most common adverse events reported during the therapy of chronic hepatitis B and C, with some recommendations for proper management.

Early identification of achieving a sustained virological response in chronic hepatitis C patients without a rapid virological response

BACKGROUND AND AIM

A number of hepatitis C virus (HCV) patients without a rapid virological response (RVR) achieved a sustained virological response (SVR) with peginterferon-alpha-2a/ribavirin. The aim of this study was to identify factors associated with SVR in non-RVR patients.

METHODS

Baseline and on-treatment factors were used to explore the prognostic factors for SVR in 113 HCV genotype-1 (HCV-1) and 20 HCV-2 non-RVR patients in two randomized trials.

RESULTS

The SVR rate in HCV-1 patients with a complete early virological response (cEVR) and partial early virological response was 91.9% versus 45% (P < 0.001) and 21.4% versus 10% (P = 0.62), respectively, after 48 and 24 weeks of treatment. The SVR rate in HCV-2 patients with a cEVR was 90.9% versus 57.1% (P = 0.25), respectively, after 24 and 16 weeks of treatment. Multivariate analysis showed that cEVR and standard regimen were independently associated with SVR. Viral kinetic study revealed that HCV viral loads < 10,000 IU/mL at week 4 were the best predictor of cEVR for both HCV-1 and HCV-2 non-RVR patients with the accuracy of 81% and 95%, respectively, and also of SVR with the accuracy of 78% and 92%, respectively, in patients receiving standard of care. The most important independent predictors for cEVR were HCV viral loads < 10(4) IU/mL at week 4, followed by increased ribavirin dose within 12 weeks of treatment.

CONCLUSIONS

Achieving a cEVR with standard of care is the most important predictor of SVR in non-RVR patients. Week 4 viral loads < 10,000 IU/mL could accurately predict cEVR early and following SVR in non-SVR patients.

Management of hepatitis C; Report of the Consensus Meeting at the 45th Annual Meeting of the Japan Society of Hepatology (2009)

The consensus meeting for the diagnosis, management and treatment for hepatitis C was held in 45(th) annual meeting for the Japan Society of Hepatology (JSH) in June 2009 where the recommendations and informative statements were discussed including organizers and presenters. The Several important informative statements and recommendations have been shown. This was the fourth JSH consensus meeting of hepatitis C, however, the recommendations have not been published in English previously. Thus, this is the first report of JSH consensus of hepatitis C. The rate of development of hepatocellular carcinoma (HCC) in HCV-infected patients in Japan is higher than in the USA, because the average age of the HCV-infected patients is greater and there are more patients with severe fibrosis of the liver than in the USA. In Japan, more than 60% of HCV-infected patients are genotype 1b infection, and they show lower response to perinterferon and ribavirin combination treatment. To improve the response rate is also an important issue in our country. To establish the original recommendations and informative statements to prevent the development of HCC is a very important issue in Japan.

Preemptive erythropoietin plus high ribavirin doses to increase rapid virological responses in HIV patients treated for chronic hepatitis C

Chronic hepatitis C affects one-third of HIV(+) patients worldwide. High ribavirin (RBV) exposure is crucial to maximize the response to hepatitis C therapy in this population, although it may increase the risk for hemolytic anemia. PERICO is a prospective multicenter trial in which HIV/HCV-coinfected patients are randomized to receive peginterferon (pegIFN) alfa-2a 180 microg/week plus either weight-based RBV (1000-1200 mg/day) or RBV 2000 mg/day, the latest along with erythropoietin alfa (EPO) 30,000 IU/week from the first day until week 4. A total of 149 patients were assessed in a planned interim analysis at week 4. In both arms, 22% of patients achieved negative HCV-RNA (rapid virological response, RVR). Multivariate analysis [OR (IC 95%), p] showed that factors associated with RVR were HCV genotypes 2/3 vs. 1/4 [20 (5-100), <0.01] and baseline HCV-RNA [0.16 (0.07-0.37) per log IU/ml, <0.01]. The occurrence of severe anemia (hemoglobin <10 g/dl) did not differ when comparing RBV vs. high RBV + EPO (7% vs. 3%; p = 0.4). Moreover, RBV plasma trough levels were comparable at week 4 (1.9 vs. 2.4 microg/ml; p = 0.2). Use of high RBV doses with preemptive EPO during the first 4 weeks of hepatitis C therapy is safe, but fails to enhance significantly RBV plasma exposure and RVR rates. Extensive intraerythrocyte accumulation of RBV following boosted production of red blood cells by EPO could explain these findings.

Use of epoetin beta during combination therapy of infection with hepatitis c virus with ribavirin improves a sustained viral response

The aim of the study was to evaluate the effects of epoetin-beta on anemia and sustained viral response in patients with chronic hepatitis C receiving treatment with pegylated interferon and ribavirin. Forty-two Caucasian patients with chronic hepatitis C infection, treated with pegylated interferon alpha-2a or alpha-2b plus ribavirin, who experienced at least a 2 log decline in HCV-RNA in the first month of therapy and a > or =2.5 g/dl hemoglobin drop from baseline, were recruited. They were divided into two groups: 22 patients received epoetin-beta 30,000 U administered s.c. q.w. (group A) and 20 patients received a reduced ribavirin dose of 600 mg daily (group B). The end-of-treatment response was 95.4% (21/22) in group A and 80% (16/20) (P = 0.2) in group B. Sustained viral response in group A was 81.8% (18/22), statistically higher than in group B (45%, 9/20) (P = 0.03). Mean corpuscular volume of erythrocytes was statistically lower in group A than in group B 4 weeks after starting epoetin-beta or reduced ribavirin dose (P < 0.001), end-of-treatment (P < 0.001) and after 6 months follow-up (P < 0.001). A negative correlation between the levels of ferritin serum was found in group A at the baseline and mean corpuscular volume value after 1 month of combination antiviral therapy (r = -0.45; P = 0.35), 4 weeks after starting epoetin-beta (r = -0.43; P = 0.04) and after 6 months follow-up (r = -0.45; P = 0.03). Administration of epoetin-beta increases sustained viral response rates among patients developing anemia, because the standard dose of ribavirin is maintained, thereby reducing the side-effects of antiviral treatment.

Optimizing the treatment of chronic viral hepatitis C

Chronic hepatitis C is a major health concern. The current standard therapy is based on a combination of pegylated (PEG)-IFN-alpha and ribavirin (RBV). This treatment produces a sustained virological response (SVR) in approximately 55% of chronically infected patients. A number of virological factors (e.g., the hepatitis C virus [HCV] genotype and baseline titer of HCV RNA) may influence the treatment response. Indeed, the SVR rate is approximately 80% for patients infected with HCV genotypes 2 or 3, and approximately 45% for genotype 1 or 4 patients. Furthermore, the treatment duration can be modified as a function of the genotype. New drugs are being developed for the treatment of chronic hepatitis C but will probably be used in combination with the current standard therapy. This means that improvements in therapy based on a PEG-IFN-RBV combination will remain a true challenge in the coming years. Recent clinical trial results have demonstrated that the current therapy can be optimized. Modulation of the treatment duration and/or the RBV dose may increase the SVR rate. The present article reviews the current approaches to optimizing the treatment of chronic hepatitis C.

Antiviral therapy of chronic hepatitis C in patients with advanced liver disease and after liver transplantation

Chronic infection with the hepatitis C virus (HCV) represents one of the major causes for end-stage liver disease worldwide. Although liver transplantation offers an effective treatment, HCV reinfection of the transplanted graft is a critical and almost inevitable complication with major influence on graft- and patient survival. Pre-transplant antiviral therapy in advanced liver disease is limited by poor tolerance and only applicable to mildly decompensated patients but was able to show promising results in patients reaching negative viral load when undergoing transplantation. Prophylactic therapy with HCV antibodies during the anhepatic phase has not been shown to be effective in studies to date. Antiviral therapy after transplantation but before evidence of reinfection, so called pre-emptive treatment, is limited by frequent complications and a high rate of side effects. The mainstay of management represents directed antiviral therapy after evidence of recurrence of chronic Hepatitis C. With a combination therapy of pegylated interferon and ribavirin, sustained virologic response rates of 25-45% are achieved. However, tolerability is often poor, and the need of dose reduction is frequent. To date, there is no general consensus on modality, timing and dosing of antiviral treatment of HCV in patients with advanced liver disease and after liver transplantation. More randomised, controlled trials are needed. Moreover, upcoming new treatment approaches, e.g. specifically targeted antiviral therapy for hepatitis C (STAT-C) with HCV-specific polymerase and protease inhibitors, may represent a therapeutic alternative.

Assessment of the efficacy of reducing peginterferon alpha-2a and ribavirin dose on virologic response in Koreans with chronic hepatitis C

BACKGROUND/AIMS

The virologic response of Koreans to combination therapy for chronic hepatitis C is similar to westerns; however, dose modification occurs more frequently in Koreans. We evaluated the rates of peginterferon alpha-2a and ribavirin dose modifications and their effect on the virologic response in Koreans.

METHODS

Patients with detectable HCV RNA and enrolled from multicenters were treated with peginterferon alpha-2a (180 microg/week) and ribavirin (800 mg/day) for 24 weeks (genotype non-1, n=37) or peginterferon alpha-2a (180 microg/week) and ribavirin (1,000-1,200 mg/day) for 48 weeks (genotype 1, n=55).

RESULTS

Early virologic response (EVR) and sustained virologic response (SVR) were 77.2% (genotype 1, 75%; non-1, 81%) and 66.3% (genotype 1, 56%; non-1, 81%), respectively. The frequency of dose modification was 32.6% within the first 12 weeks and 52.2% during the entire treatment period. No difference was found in SVR regardless of dose modification. However, the SVR for patients using >or=80% of the peginterferon dose was significantly higher than for those using <80% (81.3 vs. 50.0%, p=0.007), despite varying ribavirin doses. No difference was found in SVR regardless of whether the ribavirin dose was <80% or not. These results did not change based on genotype.

CONCLUSIONS

We suggest that using at least 80% of the peginterferon alpha-2a dose in Koreans not only maintains SVR but also reduces drug side effects during the entire treatment period. A lower dose of ribavirin may be as efficacious as a standard dose.

Pegylated interferon alpha-2b (Peg-IFN alpha-2b) affects early virologic response dose-dependently in patients with chronic hepatitis C genotype 1 during treatment with Peg-IFN alpha-2b plus ribavirin

Chronic hepatitis C (CH-C) genotype 1 patients who achieved early virologic response have a high probability of sustained virologic response (SVR) following pegylated interferon (Peg-IFN) plus ribavirin therapy. This study was conducted to evaluate how reducing drug doses affects complete early virologic response (c-EVR) defined as hepatitis C virus (HCV) RNA negativity at week 12. Nine hundred eighty-four patients with CH-C genotype 1 were enrolled. Drug doses were evaluated independently on a body weight base from doses actually taken. From multivariate analysis, the mean dose of Peg-IFN alpha-2b during the first 12 weeks was the independent factor for c-EVR (P = 0.02), not ribavirin. The c-EVR rate was 55% in patients receiving > or = 1.2 microg/kg/week of Peg-IFN, and declined to 38% at 0.9-1.2 microg/kg/week, and 22% in patients given <0.9 microg/kg/week (P < 0.0001). Even with stratified analysis according to ribavirin dose, the dose-dependent effect of Peg-IFN on c-EVR was observed, and similar c-EVR rates were obtained if the dose categories of Peg-IFN were the same. Furthermore, the mean dose of Peg-IFN during the first 12 weeks affected HCV RNA negativity at week 24 (P < 0.0001) and SVR (P < 0.0001) in a dose-dependent manner. Our results suggest that Peg-IFN was dose-dependently correlated with c-EVR, independently of ribavirin dose. Thus, maintaining the Peg-IFN dose as high as possible during the first 12 weeks can yield HCV RNA negativity and higher c-EVR rates, leading to better SVR rates in patients with CH-C genotype 1.