NEW YORK (Reuters Health) - Combined pegylated interferon and ribavirin are effective in treatment of chronic hepatitis C virus (HCV) genotype 6 infection, researchers report in a January 17th on-line paper in the Journal of Hepatology.
Dr. K. Rajender Reddy told Reuters Health by email, "Genotype 6 infection hepatitis C infection is common in certain countries such as Vietnam and there is sparse data on the effectiveness of therapy with pegylated interferon and ribavirin."
"This large randomized study," he added, "provides new information on treatment of genotype 6 patients, particularly on shortening duration of therapy in select patients thus limiting costs of an expensive treatment."
Dr. Reddy of the University of Pennsylvania, Philadelphia and colleagues note that the combination is standard treatment for HCV, but genotype is considered to be a strong predictor of sustained virological response (SVR) and little is known about response and optimal treatment duration with genotype 6.
To investigate further, the team conducted an open-label trial in 105 treatment-naïve HCV genotype 6 patients. They were randomized to 24 or 48 weeks of treatment with pegylated interferon alfa-2a 180 mcg per week and ribavirin 15 mg/kg per day.
The study had no support and the patients had to pay for their care. Six dropped out for economic reasons and another 7 were lost to follow-up.
However, intention-to-treat analysis showed an SVR in 60% of the 24-week group and 71% of those in the 48-week group. The difference was not significant. Corresponding biochemical responses were 63% and 77%.
In all, 7% in the shorter duration group and 5% of the longer treatment group had a virological relapse.
Overall, SVR was greatest in those with a rapid virological response. In the 24-week group, 75% of such patients achieved SVR. In the 48-week group, the proportion was 86%.
Hematologic and general adverse events were similar between the two groups, except the rate of anemia was lower with shorter treatment duration (31% versus 57%).
The researchers point out that a "A duration of 24 weeks of therapy in younger patients, with low viral load and rapid virological response appeared equally effective as 48 weeks of therapy and this is likely to have a major economic impact on HCV therapy, in such subpopulations."
In fact, Dr. Reddy noted that the efficacy of shorter duration therapy is scientifically worth pursuing in larger trials, but given the lack of support for the current study, "challenges are in funding."
"While new drugs are being developed for non-genotype 6 hepatitis C infections," he concluded, "pegylated interferon and ribavirin will remain the standard of care for the foreseeable future for genotype 6 infections."
A Randomized Trial of 48 versus 24 Weeks of Combination Pegylated Interferon and Ribavirin Therapy in Genotype 6 Chronic Hepatitis C
J Hepatol 2012.