Clinical

Tailored ribavirin dosage more effective against HCV-1

Last Updated: 2007-10-16 15:12:24 -0400 (Reuters Health)

By David Douglas

NEW YORK (Reuters Health) - Treatment of chronic hepatitis C (HCV) virus genotype 1 using a weight-based ribavirin dosage in combination with peginterferon alfa-2b for 48 weeks is more effective than using a flat dosage of ribavirin, researchers report in the October issue of Hepatology.

This approach is particularly successful in African Americans.

However, "in patients with genotypes 2 and 3," lead investigator Dr. Ira M. Jacobson told Reuters Health, "weight-based dosing did not confer a significant advantage over flat dosing and 24 weeks of therapy was as effective as 48 weeks."

Dr. Jacobson of Weill Medical College of Cornell University, New York and colleagues studied 5027 patients randomized to peginterferon alfa-2b (1.5/mcg/kg per week) and daily ribavirin 800 mg or peginterferon alfa-2b and a weight-based dosage between 800 and 1400 mg per day.

Patients with genotypes 1, 4, 5, and 6 were treated for 48 weeks. Those with genotypes 2 or 3 were treated for 24 or 48 weeks.

Significantly more patients given the weight-based dosage achieved a sustained viral response compared with those given the flat dose (44.2% versus 40.5%, respectively; p = 0.008). Relapse rates were also lower in the weight-based groups.

In a second paper in the same issue of the journal, Dr. Jacobson and colleagues report on the results of a subgroup of 362 African Americans with genotype 1 disease who took part in the study. "We found that the most profound impact of weight-based ribavirin dosing was in this group of patients," Dr. Jacobson observed.

The approach showed even greater sustained viral response (21% versus 10%; p = 0.0006) and reduced relapse rates (22% versus 30%) in patients given weight-based ribavirin.

"This reinforces the critical importance of adequate ribavirin dosing in patients with intrinsically impaired response to interferon," added Dr. Jacobson, "an observation made in previous studies in African Americans as well."

In an accompanying editorial, Dr. Steven-Huy B. Han of the David Geffen School of Medicine at University of California and Dr. Jason Smith of the Greater Los Angeles Veterans Healthcare Administration Hospital conclude that further study is needed but "the traditional notion that ribavirin dosage should be fixed has now been sidelined by the idea that we should tailor ribavirin dosing to our patients."

Hepatology 2007;46:953-956,971-990.