Interferon-alpha-2b treatment of chronic hepatitis C in children with hemophilia

The natural history of hepatitis C virus infection acquired during childhood

BACKGROUND

The outcome of patients with hepatitis C virus (HCV) infection acquired during childhood in the absence of antiviral therapy is not clear.

AIMS

The purpose of this study was to review the outcome of untreated HCV acquired in childhood. Only population-based studies were included, as referred cases would be predicted to have more severe disease.

METHODS

A systematic review of the literature was completed up to October 2010 to identify studies where a population was screened for HCV infection that was presumably acquired during childhood. Demographical and clinical data were collected on infected patients who had not been treated with an antiviral. Primary outcome was development of a severe adverse outcome (cirrhosis, hepatoma, need for a liver transplant or liver-related death).

RESULTS

There were 25 studies reporting a total of 733 infected patients. Liver biopsy results were provided for 180 patients (25%), revealing cirrhosis in eight (1.0% of the total and 4.0% of those who had a biopsy). None of the other patients developed a severe adverse outcome. As a result of the small number of patients with a severe adverse outcome, risk factors for HCV progression could not be identified.

CONCLUSION

Although HCV can lead to liver transplantation and death during childhood, the vast majority of patients with disease acquired during childhood have slowly progressive disease. There is no clear indication for antiviral therapy in the majority of children with HCV infection.

Guidance for clinical trials for children and adolescents with chronic hepatitis C

Most children with chronic hepatitis C are infected vertically, have a low natural seroconversion rate, and carry a lifetime risk of cirrhosis and cancer. Affected children are usually asymptomatic, and histological findings are mild with a low risk of progression, although 5% develop significant liver disease in childhood.The use of combination treatment with pegylated interferon-α and ribavirin has changed the outcome and prognosis for this disease, with approximately 60% of children achieving sustained viral clearance. Combination therapy is not ideal for children because pegylated interferon is administered subcutaneously, impairs growth velocity, and both interferon and ribavirin have significant adverse effects that affect compliance. In addition, approximately 50% of children infected with genotype 1 do not respond to therapy. Thus, additional treatment options are required including improvement in dosing, reduction in the length of treatment, and evaluation of new drugs, such as protease inhibitors, which could be more effective for patients infected with genotype 1.The primary goal of treatment is to eradicate the infection. The future clinical trial design should ensure that any new drugs demonstrate noninferiority to the present standard regimen in both children and adults. The measure for documenting substantial improvement above present therapy should be increased viral clearance rate or the same clearance rate, with a shorter duration of treatment and/or fewer adverse effects. We do not believe there is any need for a placebo arm because approved therapy is available and new treatments can be compared with present therapy.Safety measures should include the standard recommended laboratory investigations, growth parameters, quality-of-life or psychological measures, and a requirement for long-term follow-up for up to 5 years.

Treatment of hepatitis C in children: a systematic review

BACKGROUND

Current guidelines recommend children be treated for hepatitis C virus (HCV) using the same principles applied in adults. There are however few published studies which assess the efficacy and safety of HCV therapy in children.

METHODOLOGY/PRINCIPAL FINDINGS

A systematic review of the literature was completed for studies of any design that evaluated HCV therapy in children. The primary outcome was sustained virologic response (SVR), with sub-group analysis of response rates by genotype. There were 4 randomized controlled trials (RCTs) and 31 non-randomized studies, all involving interferon, pegylated interferon (PEG-IFN), or combinations of these drugs with ribavirin. The SVR rate could not be directly compared as the populations and interventions differed across studies. Genotype was not reported or differed substantially from study to study. The overall SVR rate for PEG-IFN and ribavirin ranged from 30 to 100% which is comparable to the rate in adults. Similar to adults, the SVR rates were significantly higher in children with genotype 2 or 3 compared to genotype 1. Adverse effects were primarily flu-like symptoms and neutropenia. There were insufficient data to assess the applicability of the week 12 stop rule (stopping therapy at week 12 if there is less than a 2 log drop in HCV RNA) or the efficacy of shortening therapy to 24 weeks in children with genotype 2 and 3.

CONCLUSIONS/SIGNIFICANCE

Current guidelines for the treatment of HCV in children are based on limited data. Further research is needed to define the optimal therapy for HCV in children.

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

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.

Interferon alpha in the treatment of chronic hepatitis C in children: a meta-analysis [correction of metanalysis]

Children with chronic hepatitis C may be ideal candidates for treatment with interferon alpha (IFNalpha) as they have liver disease at an early stage. However, adverse drug reactions need to be considered. The aim of this study was to conduct a systematic review of literature on interferon therapy of chronic hepatitis C in children, and to perform a meta-analysis of pooled data. A computerized search gave 18 articles on IFNalpha therapy in children with chronic hepatitis C; after exclusion of uncontrolled trials and of trials including patients with comorbidities, data from two studies could be pooled (48 patients). The outcomes assessed were biochemical, defined as normalization of alanine transaminase, and virologic, defined as HCV-RNA loss, both sustained at 24 months after enrollment. Results of the studies were homogenous. Risk difference was 37% (95%CI: 12.9-61) in favour of IFNalpha treated children for sustained biochemical response, and 36.8% (95%CI: 14.3-59.3) in favour of treated children for sustained HCV clearance, respectively. The differences were highly significant (P = 0.007 and P = 0.004, respectively). The histological end-point, as well as side-effects, could not be analysed, due to lack of data. This review identifies the poor methodology of the majority of the published trials. The study provides support for the efficacy of IFNalpha in improving both biochemical and virologic outcomes in chronic hepatitis C in children, but evidence is confined to these surrogate end-points.

Children with hepatitis C

An estimated 240,000 children in the United States have antibody to hepatitis C virus (HCV) and 68,000 to 100,000 are chronically infected with HCV. Acute HCV infection is rarely recognized in children outside of special circumstances such as a known exposure from an HCV-infected mother or after blood transfusion. Most chronically infected children are asymptomatic and have normal or only mildly abnormal alanine aminotransferase levels. Although the natural history of HCV infection acquired in childhood seems benign in the majority of instances, the infection takes an aggressive course in a proportion of cases leading to cirrhosis and end-stage liver disease during childhood; the factors responsible for a more aggressive course are unidentified. An optimal approach to management of hepatitis C in children would be prevention, particularly of perinatal transmission, which is now the major cause of new cases of hepatitis C in children. Obstetrical factors may be important determinants of transmission, which, if confirmed, should lead to changes in the care of infected women. Therapy of HCV infection in children is also not well defined. There have been no large randomized, controlled trials of therapy in children with chronic hepatitis C. Small heterogeneous studies of interferon monotherapy have reported sustained virological response rates of 35% to 40%. There are few data regarding the use of combination therapy with interferon and ribavirin in children and no information on the use of peginterferon. Clearly, there are important needs for future epidemiologic and clinical research on hepatitis C in childhood.

Children with hepatitis C

An estimated 240,000 children in the United States have antibody to hepatitis C virus (HCV) and 68,000 to 100,000 are chronically infected with HCV. Acute HCV infection is rarely recognized in children outside of special circumstances such as a known exposure from an HCV-infected mother or after blood transfusion. Most chronically infected children are asymptomatic and have normal or only mildly abnormal alanine aminotransferase levels. Although the natural history of HCV infection acquired in childhood seems benign in the majority of instances, the infection takes an aggressive course in a proportion of cases leading to cirrhosis and end-stage liver disease during childhood; the factors responsible for a more aggressive course are unidentified. An optimal approach to management of hepatitis C in children would be prevention, particularly of perinatal transmission, which is now the major cause of new cases of hepatitis C in children. Obstetrical factors may be important determinants of transmission, which, if confirmed, should lead to changes in the care of infected women. Therapy of HCV infection in children is also not well defined. There have been no large randomized, controlled trials of therapy in children with chronic hepatitis C. Small heterogeneous studies of interferon monotherapy have reported sustained virological response rates of 35% to 40%. There are few data regarding the use of combination therapy with interferon and ribavirin in children and no information on the use of peginterferon. Clearly, there are important needs for future epidemiologic and clinical research on hepatitis C in childhood.

Does interferon and ribavirin combination therapy increase the rate of treatment response in children with hepatitis C?

BACKGROUND

Interferon-alpha was the first accepted treatment of chronic hepatitis C. In recent years, adding ribavirin has produced better response rates in adult patients than monotherapy with interferon-alpha. Whether adding ribavirin also improves treatment results in pediatric patients remains unclear.

METHODS

Twelve patients were given 3 million U/m 2 subcutaneous interferon-alpha three times weekly and 15 mg/kg oral ribavirin daily, and 10 patients were given only 3 million U/m 2 subcutaneous interferon-alpha three times weekly for a total of 12 months.

RESULTS

The dropout rate was 22.8% (25% for patients receiving combination treatment versus 20% for those receiving monotherapy). At the end of treatment, viral clearance was achieved in 50% of the patients who received combination treatment versus 30% of those who received monotherapy. After 12 months of posttreatment follow-up, sustained response rates were 30% and 41.7%, respectively. Of those who responded to treatment, 66.7% had received ribavirin whereas 37.5% of nonresponders had received ribavirin therapy.

CONCLUSION

Adding ribavirin to interferon treatment improved end-of-treatment response rates in children with chronic hepatitis C. Tolerance of treatment was similar to tolerance of monotherapy. However, studies of greater numbers of pediatric patients with longer follow-up periods are necessary to determine prolonged sustained response.

An analysis of published trials of interferon monotherapy in children with chronic hepatitis C

BACKGROUND

Although no therapeutic regimen has received Food and Drug Administration approval for treating children with chronic hepatitis C viral infection (CHC), there have been a number of pediatric interferon-alpha (IFN-alpha) trials. The purpose of this study was to perform a critical review of these trials to determine 1) end-of-treatment (ETR) and sustained-response (SR) rates, 2) predictors of response to therapy, and 3) safety of and tolerance to IFN-alpha in children with CHC.

METHODS

Relevant studies in the English-language medical literature and abstracts (January 1990 through November 2000) were identified by searching for manuscripts that contained the key words "children," "hepatitis C," and "interferon." Trials were considered eligible for inclusion in this analysis if criteria for treatment included positive serum polymerase chain reaction for hepatitis C virus RNA (HCV PCR).

RESULTS

Twenty published manuscripts of the use of IFN-alpha in children with CHC were found, of which 12 met our inclusion criteria. Twenty-two abstracts, of which seven met our inclusion criteria, were identified. In the 19 included trials, 366 treated and 105 untreated children were observed; five countries were represented. Average ETR was 54% (0%-91%) and average SR was 36% (0%-73%). The SR in children with genotype 1 was 27% versus 70% for nongenotype 1 ( P = 0.001). Five of 105 (5%) untreated controls exhibited spontaneous viral clearance.

CONCLUSIONS

To date, there is no published large-scale, multicenter, prospective, placebo-controlled randomized trial of the use of IFN-alpha in children with CHC. The data in this review suggest that IFN-alpha in children with CHC does have reasonable efficacy and safety. This review highlights the need for a more systematic design of future pediatric CHC trials. Ideally, such trials would be large scale, prospective, and controlled, and would include HCV genotype and viral load, histology, quality of life measures, and systematic recording of adverse events and of effects of therapy on growth and development.

Interferon-alpha treatment of chronic hepatitis C in children with hemophilia

BACKGROUND

In children with hemophilia, hepatitis C virus (HCV) is the major cause of chronic liver disease. In this study, long-term efficacy of interferon-alpha was studied to determine the factors that predict a sustained response to interferon therapy in young children with hemophilia who have chronic hepatitis C.

METHODS

Seventeen Korean children with hemophilia and chronic hepatitis C were treated with 3.7 million units/m2 of interferon-alpha2a three times weekly for 6 months. Liver biopsy, pretreatment serum HCV RNA quantitation with competitive reverse transcription assay, and HCV genotyping with reverse hybridization assay were performed.

RESULTS

Hepatitis C virus genotypes 1a, 1b, and 2a were found in three (18%), five (29%), and six (35%) patients, respectively. Interferon-alpha was well tolerated, and the frequency of bleeding did not increase. Of the 17 patients, 7 (41%) had a sustained response for 3 years after the end of therapy. Patients with a sustained response had lower pretreatment serum HCV RNA levels. One (13%) of eight patients with genotype 1 and five (83%) of six with genotype 2 had a sustained response (P < 0.05).

CONCLUSIONS

Interferon-alpha treatment of chronic hepatitis C in children with hemophilia was safe and effective in producing sustained responses. The pretreatment serum HCV RNA level and viral genotype may be predictive factors for sustained response to interferon therapy.

Viral hepatitis. From prevention to antivirals

The challenge of viral hepatitis has been acknowledged and confronted in the last decade. Significant progress in prevention of infection with HAV and HBV may eradicate these serious infections from the United States and other parts of the world in the coming decades. Application of prophylactic strategies to children will be a major mechanism in accomplishing this task. The quest for potent antiviral medications continues. The next critically important development will be ways to prevent new HCV infections and to treat the millions of already infected individuals at risk for the serious consequences of this disease. For pediatricians, realizing these goals requires a greater understanding of perinatal HCV transmission, use of vaccines for prevention of viral hepatitis, and identification of HCV-infected children who are likely to benefit from new therapeutic strategies as they become available.

Treatment of chronic hepatitis C in pediatric patients

Although HCV infection in children shares some clinical features with that in adults, it is clearly different in several ways. These differences may have important implications for treatment. Some differences, such as milder disease, less frequent extrahepatic manifestations, and fewer comorbid conditions causing progression, argue against aggressive treatment in childhood. Other factors, such as less severe liver disease, shorter disease duration, possibly higher rates of sustained virologic response, and better tolerance of IFN, may be reasons to pursue treatment before advanced hepatic injury occurs. Given the relatively small number of pediatric patients with HCV infection and the gaps in the current understanding of natural history and effects of therapy in these patients, treatment should be undertaken only in clinical trials, so that careful data collection and monitoring can define more precisely the safety and efficacy of IFN therapy in children.

Interferon-alpha treatment of chronic hepatitis C virus infection in children

OBJECTIVES

To determine the safety and efficacy of interferon-alpha therapy of chronic hepatitis C virus (HCV) infection in children.

STUDY DESIGN

This was an open-labeled prospective trial of interferon-alpha-2a (IFN-alpha) in children with evidence of HCV infection for at least 6 months. Twenty-three children were enrolled and treated with IFN-alpha at a dosage of 3 million units/m2 three times weekly. Beginning in 1995 patients defined as complete or partial responders after 6 months were offered an additional 6 months of treatment. Endpoints were alanine aminotransferase normalization and loss of hepatitis C viral ribonucleic acid from serum. Responders were compared with nonresponders for age, gender, duration of infection, pretreatment alanine aminotransferase and hepatitis C viral ribonucleic acid levels, saturation of serum iron-binding capacity, histologic score of chronic hepatitis and viral genotype. Statistical methods used for these comparisons included the Kruskal-Wallis test, the Mann-Whitney two-sample test and the Fisher exact test.

RESULTS

Of the 21 children who completed at least 6 months of treatment, 4 (19%) had complete response, 8 (38%) had partial response and 9 (43%) had no response. Three of the 4 complete responders had prolonged treatment; in 2 the response was maintained. One responder relapsed but responded to a second, longer course of treatment. Four of the 8 partial responders had prolonged therapy and 3 of them became complete responders. One child who was originally a nonresponder lost HCV RNA within the first year after therapy. Thus eventually 7 (33%) of 21 patients were complete responders. After at least 12 months of follow-up on most of these children, no relapses have been observed. No differences in any of the variables tested could be demonstrated between responders and nonresponders, but small sample size limits power. IFN-alpha was discontinued in only one child because of side effects, and temporary dosage adjustments were needed in 4 children.

CONCLUSIONS

IFN-alpha is of some efficacy in the treatment of chronic HCV infection in children. Complete or partial responders at 6 months should undergo prolonged treatment.