NEW YORK (Reuters Health) Jan 01 - In selected patients with hepatitis C virus (HCV) infection, a shortened 24-week course of pegylated interferon (PEG IFN) and ribavirin can be considered: those with HCV genotype 1, a rapid decrease in viral load, and low HCV RNA at baseline, according to French researchers.

In the January issue of the Journal of Hepatology, Dr. Christophe Moreno of Hopital Claude Huriez, Lille and colleagues conducted a meta-analysis of 7 randomized controlled trials. Six studies compared 24 and 48 weeks of treatment; the remaining study compared 18 and 48 weeks.

Overall, the studies involved 807 treatment naive patients with HCV-1, rapid viral decline (i.e., a 2-log viral load drop or undetectable HCV RNA) within four weeks of treatment. Four hundred ten patients were treated for 48 weeks and 397 for shorter periods.

Sustained virological response rates were lower (mean difference, 13.6%; p=0.004) when treatment was given for less than 48 weeks. Thus, say the investigators, one SVR "would be lost when 7 patients underwent less than 48 weeks of therapy as compared to the expected rate in the 48-week treatment group."

The relapse rate was also significantly higher among patients treated for less than 48 weeks (mean difference, 9.9%).

However, there was no significant effect of shorter treatment duration on the end-of-treatment virological response rate (mean difference, 1.5%).

Also, in the subgroup of patients with undetectable HCV-RNA at week 4 and a baseline HCV-RNA level of no more than 400,000 IU/mL, there was no significant difference between sustained virological responses after 24 or 48 weeks of treatment.

The researchers conclude that these are the only patients who should be considered for shorter treatment. However, they add, "the optimal cut-off defining low baseline viral load and the impact of the presence of other factors capable of altering treatment response, remain subject to debate."

J Hepatol 2010;52:25-31.