Low virological response to interferon in children with chronic hepatitis C

Systematic review with meta-analysis: comparison between therapeutic regimens for paediatric chronic hepatitis C

BACKGROUND

To decide when and how to treat children with chronic hepatitis C is an ongoing debate.

AIM

To compare the outcomes of therapy for children with chronic hepatitis C.

METHODS

An electronic database assessed clinical trials with sustained virological response rates specified by genotype. The data were extracted according to the therapeutic regimen; interferonα±ribavirin and pegylated interferonα±ribavirin.

RESULTS

The search sourced 23 peer-reviewed articles which enrolled 934 cases, aged 2-19 years. Sustained virological response rates were significantly higher with the addition of ribavirin to either interferonα or pegylated nterferonα vs. their monotherapies for genotypes 1,2&3 with crude and weighted estimates. The weighted estimate indicated higher sustained virological response rates for those treated with pegylated interferonα+ribavirin vs. interferonα+ribavirin for genotype 1 (50% vs. 40%) and genotypes 2&3 (90% vs. 84%), (odds ratio 1.5, 95% confidence interval 1.2-1.8, and 1.8, 1.2-2.9 respectively). Cases with genotype 4 treated with pegylated interferonα+ribavirin had a lower sustained virological response (41%) vs. genotype 1 (1.4, 1.2-1.8), and vs. genotypes 2&3 (13.5, 10.3-17.9). Some adverse events were significantly higher among cases treated with pegylated interferonα+ribavirin vs. interferonα+ribavirin.

CONCLUSIONS

Despite the superiority of pegylated interferonα+ribavirin to interferonα+ribavirin for the treatment of chronic hepatitis C among children, the significant higher adverse events along with the modest outcome for genotypes 1&4 render that regimen a suboptimal therapy. These data indicated the need for the future comparison with clinical trials of direct anti-viral drugs for children with chronic hepatitis C.

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 for chronic hepatitis C in children: a review

The aim of this review was to evidence the actual treatment used for chronic hepatitis C virus (HCV) in children. A review of the use of interferon (IFN) as monotherapy in children demonstrates a sustained virological response (SVR) of 33%-45%. This is significantly better than the SVR rate for IFN monotherapy observed for adults. When the data are further scrutinized, the SVR for genotype 1 is 26% and 70% for other genotypes. The higher response rate observed in children might be the result of the earlier stage of the disease, higher relative IFN dosage, or lack of comorbid conditions. The use of IFN-alpha2b in combination with ribavirin was reported by Gonzalez-Peralta et al and has led to Food and Drug Administration approval of this therapy for children with a SVR significantly higher in children with HCV genotype 2/3 (84%) than in those with HCV genotype 1 (36%). About the use of pegylated IFN in combination with ribavirin, the first-line treatment in adult patients affected by chronic hepatitis C, there are few experiences. These preliminary experiences evidenced that combination treatment of PEG-IFN-alpha2b with ribavirin shows encouraging results and was well tolerated in children and adolescents with chronic hepatitis C.

Managing pediatric hepatitis C: current and emerging treatment options

Since 1992, the maternal–fetal route of transmission has become the dominant route for acquisition of hepatitis C (HCV) infection by children. With increasing knowledge of antiviral treatment for HCV infection, the main goal of therapy is to achieve a sustained virological response (SVR) as defined by undetectable serum HCV RNA by polymerase chain reaction assay six months after cessation of therapy. In young children, interferon therapy is more effective than in adults with chronic HCV infection (CHC). Although children clearly have a milder degree of liver pathology, data have indicated that hepatic inflammation from HCV infection can progress to fibrosis or cirrhosis in children. Hepatocellular carcinoma has been reported in adolescents with CHC. In this article, recent improvements in therapy of children with CHC and in the clinical development of new emerging drugs with potential use in children will be reviewed.

Design of the PEDS-C trial: pegylated interferon +/- ribavirin for children with chronic hepatitis C viral infection

BACKGROUND

PEDS-C is the first multicenter placebo-controlled trial for the treatment of chronic hepatitis C (HCV) in childhood that has ever been conducted in the United States (USA). Establishment of the research team, protocol, administrative infrastructure, and ancillary contributors for the pediatric trial took years of planning.

PURPOSE

To study the safety and efficacy of pegylated-interferon alpha (PEG-2a) plus ribavirin (RV) with PEG-2a monotherapy in children aged 5 years through 18 years. To assess the health-related quality of life and growth and body composition in children with chronic hepatitis C infection, before, during, and after treatment.

METHODS

Eleven centers of pediatric hepatobiliary clinical research were united in a National Institutes of Diabetes and Digestive and Kidney Diseases (NIDDK) funded grant with financial support from the Food and Drug Administration (FDA) and a corporate sponsor to conduct the treatment trial.

LIMITATIONS

The most important initial limitation in the design of this complex study was securing the financial support and infrastructural organization, a process that took several years. Challenges faced by the study group included identifying the optimal study design given the limited study population, and determining what ancillary studies could be incorporated into the treatment trial.

CONCLUSIONS

In this article the process taken to design the study and administrative infrastructure, the lessons learned, and the controversial issues deliberated during the planning process are discussed. The evolution of the study and the considerations taken in the development of the protocol are valuable tools which can be applied to pediatric clinical trials in general.

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.

Hepatitis C virus infection in children coinfected with HIV: epidemiology and management

Mothers with hepatitis C virus (HCV) and HIV coinfection are the major source of HCV/HIV coinfection in infancy and childhood. There is no known intervention capable of interrupting HCV spread from mother to child, while the majority of infant HIV infections occurring in the developed world can be prevented by antiretroviral prophylaxis in the mother and child, elective caesarean section, and formula-feeding. In the era preceding treatment of HIV infection with highly active antiretroviral therapy, HCV coinfection was of little concern because the short-term survival of patients with HIV infection prevented the slowly developing consequences of chronic hepatitis C. As the life expectancy of patients with HIV infection increased with therapy, HCV has emerged as a significant pathogen. Several lines of evidence in adult patients suggest that liver disease may be more severe in patients coinfected with HIV and that progression of HIV disease may be accelerated by HCV coinfection. Whether coinfected children may share these clinical patterns remains a matter of speculation. Chronic hepatitis C in otherwise healthy children is usually a mild disease; liver damage may be sustained and fibrosis may increase over the years, suggesting slow progression of the disease. Interferon-alpha has been the only drug used in the past decade to treat hepatitis C in children and adolescents, with average response rates of 20%. Preliminary results of treatment with interferon-alpha and ribavirin suggest that the efficacy would be greater with combined therapy. These treatment protocols have not yet been applied to children coinfected with HIV, but the increasing number of long-term survivors will probably prompt further investigation in the near future. At present, treating HIV disease and monitoring HCV infection and hepatotoxicity induced by antiretroviral drugs seem to be the more reasonable approach to HCV/HIV coinfection in childhood.

Recombinant alfa-interferon plus ribavirin therapy in children and adolescents with chronic hepatitis C

Treatment with alfa-interferon alone yielded poor results in children with chronic hepatitis C and was not generally recommended. Owing to limited experience with combination therapy in children, the aim of the study was to evaluate the efficacy and tolerability of alfa-interferon 2b in combination with ribavirin in these patients with different routes of viral transmission. In an uncontrolled pilot study, 41 children and adolescents ranging from 3 to 16 years were treated with alfa-interferon at a dose of 3 or 5 MU/m(2) 3 times weekly in combination with oral ribavirin (15 mg/kg/d) for 12 months. The mode of infection was unknown in 4, parenterally transmitted in 16, and vertically transmitted in 21 children. Forty patients completed the study. Eleven children, who remained hepatitis C virus (HCV)-RNA positive 6 months after the beginning, discontinued therapy. One boy stopped treatment because of side effects. At the end of treatment 25 patients were HCV-RNA negative (61%). All individuals remained HCV-RNA negative during the 6-month follow-up period. Nine of 15 children with parenteral (56.3%), 14 of 21 with vertical (66.6%), and 2 of 4 with unknown route of infection responded. Side effects included minor clinical signs such as fever, flu-like symptoms, anorexia, and more severe signs (21.4%) such as the development of thyroid autoantibodies and impairment of thyroid function. In conclusion, combination of alfa-interferon with ribavirin seems to be an important advance in the treatment of chronic hepatitis C in children and adolescents. This also is true for both vertically infected patients and for individuals with normal transaminase levels before therapy.

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 and ribavirin in treating children and young adults with chronic hepatitis C after malignancy

OBJECTIVE

Chronic hepatitis C is a major long-term problem for children who survive cancer. Interferon (IFN)-alpha has been shown to be effective in treating patients with chronic hepatitis C; however, the rate of sustained response is low. Combining IFN-alpha and ribavirin (RBV) has been shown to significantly improve the response in adult patients with chronic hepatitis C. The aim of this pilot study was to evaluate the efficacy and safety of a combined virostatic treatment with IFN-alpha and RBV in a small cohort of children and adolescents with chronic hepatitis C and previous malignancy.

METHODS

Twelve patients with a history of a hematooncologic disease (median follow-up: 13.5 years; range: 7-14.7 years) and chronic hepatitis C were treated with recombinant IFN-alpha-2a (6 megaunits/m(2) body surface area, 3 times a week, subcutaneously) combined with RBV (15 mg/kg body weight/day, orally) for 12 months. They were tested monthly for blood counts and liver function, and for serum virus concentrations (hepatitis C virus RNA by polymerase chain reaction) every 3 months.

RESULTS

At the end of the treatment, hepatitis C virus RNA could not be detected in the serum of 8 of the 12 patients; 2 of these patients relapsed soon after therapy withdrawal, whereas 6 patients maintained in sustained virologic and biochemical remission (follow-up: 12 months). Treatment-induced toxicity was moderate and reversible with influenza-like symptoms and a decrease in blood counts in all 12 patients, alopecia in 5 of the 12, hemolysis in 4 of the 12, and weight loss of >10% in 2 of the 12.

CONCLUSIONS

As demonstrated in adults with chronic hepatitis C, treatment with IFN-alpha and RBV also seems to be an effective and safe therapeutic option for children and adolescents with chronic hepatitis C after malignancy.