Once weekly peginterferon alfa-2a is more effective than a regimen of interferon alfa-2a three times a week in patients with chronic hepatitis C, a study has shown.
According to research led by Professor Stefan Zeuzem (University of Frankfurt, Germany), peginterferon alfa-2a -interferon alfa-2a with a branched-chain polyethylene glycol moeity attached -is also a "safe" treatment for chronic hepatitis C.
The researchers randomly assigned 531 patients to receive either peginterferon alfa-2a 180µg subcutaneously once a week for 48 weeks or a regimen of interferon alfa-2a 6 million units subcutaneously three times a week for 12 weeks, followed by 3 million units three times a week for 36 weeks. They found that once weekly peginterferon alfa-2a was associated with a significantly higher rate of sustained virological response compared with the interferon alfa-2a regimen. The improved efficacy may be because of the enhanced pharmacokinetic properties of peginter-feron alfa-2a, which include sustained absorption, a slower rate of clearance and a longer half-life than unmodified interferon alfa-2a, they say (New England Journal of Medicine 2000;343:1666).
In another study, Professor E. Jenny Heathcote (Toronto Western hospital, Canada) and colleagues examined the safety and efficacy of peginterferon alfa-2a in 271 patients with chronic hepatitis C-related cirrhosis or bridging fibrosis. Peginterferon alfa-2a 180µg administered once weekly was found to be more effective than both 90µg peginterferon alfa-2a once weekly and 3 million units of interferon alfa-2a administered three times weekly (New England Journal of Medicine 2000;343:1673).
Both sets of researchers comment that the use of a combination of peginterferon alfa-2a and ribavirin in current practice requires evaluation by direct comparison with standard interferon-ribavirin combination therapy. Such studies are currently under way. Roche Pharmaceuticals hopes to receive a licence for peginterferon alfa-2a in the United Kingdom next year.