Week 4 Rapid Virological Response Predicts Sustained Response to Interferon-based Hepatitis C Treatment

SUMMARY: Rapid virological response (RVR), or undetectable plasma hepatitis C virus (HCV) RNA at 4 weeks after starting treatment with pegylated interferon plus ribavirin, has been confirmed as a good indicator of which patients will go on to achieve sustained virological response (SVR) at 6 months after completion of therapy, according to a review article published in the June 2010 issue of Alimentary Pharmacology and Therapeutics.

By Liz Highleyman

Standard treatment for chronic hepatitis C using pegylated interferon (Pegasys or PegIntron) plus ribavirin produces sustained response -- considered to be a cure -- about half the time, with HCV genotypes 2 and 3 (treated for 24 week) showing better response rates than hard-to-treat genotypes 1 or 4 (treated for 48 weeks).

Treatment is expensive and can cause difficult side effects, however, so it is useful to have an early indicator to enable patients to stop treatment that likely will not turn out to be successful.

F. Fred Poordad from Cedars-Sinai Medical Center in Los Angeles and colleagues collected data from previous published clinical trial reports in order to evaluate the predictive value of RVR as an indicator of SVR and viral relapse.

Results

• Data supported a 24-week regimen for HCV genotype 1 patients who achieved RVR.
• The positive predictive value -- or how often RVR accurately predicted SVR -- was 77.8% for patients treated for 24 weeks versus 85.7% for those treated for 48 weeks, not a significant difference.
• However, lack of RVR among genotype 1 patients "should not be viewed as a criterion for extending treatment duration beyond 48 weeks."
• Negative predictive values -- or how often lack of RVR predicted failure to achieve SVR -- were 60.9% for genotype 1 patients treated for 48 weeks and 52.7% for those treated for 72 weeks, not a significant improvement with longer therapy.
• Among people with HCV genotypes 2 or 3, RVR also had a high positive predictive value.
• Negative predictive value, however, varied according to treatment duration, indicating that a 24-week regimen is warranted for genotype 2 or 3 patients who did not achieve RVR. 

Based on these findings, the study authors concluded, "The present analysis confirms RVR as a strong predictor of SVR that can be used to tailor treatment duration, but which also should be appreciated in the context of treatment duration and regimen."

Investigator affiliation: Hepatology and Liver Transplantation, Cedars-Sinai Medical Center, Los Angeles, CA.

9/3/10

Reference
FF Poordad. Review article: the role of rapid virological response in determining treatment duration for chronic hepatitis C. Alimentary Pharmacology and Therapeutics 31(12): 1251-1267 (Abstract). June 2010.

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