A study presented Sunday, November 6 at the 62nd Annual Meeting for the American Association for the Study of Liver Diseases (AASLD) may have moved us a big step closer to a hepatitis C virus (HCV) treatment future that does away with interferon. That study found that the experimental nucleotide analogue by Pharmasset, currently dubbed PSI-7977, achieved cures in ten of ten people with HCV genotypes 2 or 3 who received it in combination with ribavirin, but without interferon.
Despite recent advances in hepatitis C virus (HCV) treatment, there remain many problems with it. Response rates with the addition of the new protease inhibitors Incivek and Victrelis have climbed substantially, especially for more difficult to treat individuals, such as those infected with HCV genotype 1. Â Nevertheless, the continued need to combine those drugs with pegylated interferon and ribavirin means that many must endure up to one year of sometimes debilitating side effects while some can’t take treatment at all.
The ten patients who achieved an HCV cure without interferon were actually enrolled in just one arm of a larger study. In that study, called ELECTRON, 40 people with HCV genotypes 2 or 3, were randomized to one of four study arms, with the aim of determining the duration of pegylated interferon therapy that would be needed when combined with 400 milligrams (mg) once-daily of PSI-7977 and ribavirin for 12 weeks. Â In one group, 10 people received pegylated interferon for the entire 12 weeks, in the second group, 10 people took pegylated interferon for 8 weeks, in the third group, 10 people took pegylated interferon for 4 weeks, and in the final group, mentioned above, the participants took no pegylated interferon at all.
Hane and his colleagues found that the duration of pegylated interferon made no difference in the cure rate, defined as maintaining undetectable HCV levels at least 24 weeks after completing treatment. All 40 participants achieved an HCV cure.
The addition of pegylated interferon did, however, make a significant difference in terms of side effects. People who received no pegylated interferon were about 20 to 30 percent less likely to experience side effects as those who received pegylated interferon.
Edward Gate, from Auckland Clinical Studies, who presented the data, reported that further studies will now move forward to explore interferon-free treatment with PSI-7977 and ribavirin, in both people with HCV genotypes 2 or 3, and in people with HCV genotype 1.