Background/aims: Pegylated interferon plus ribavirin can cause dose-limiting anemia. Taribavirin, a ribavirin prodrug, has shown a lower incidence of anemia. We sought to determine the efficacy and safety of taribavirin vs. ribavirin combined with pegylated interferon in patients with chronic hepatitis C (CHC).
Methods: This phase 2 open-label study randomized 180 patients with CHC to receive pegylated interferon alfa-2a 180 microg/week plus taribavirin 800, 1200 or 1600 mg QD or ribavirin 1000 or 1200 mg QD. Efficacy variables included proportions of patients with undetectable serum HCV RNA levels at end of treatment and after a 24-week follow-up.
Results: The proportions of patients with undetectable HCV RNA at 12 weeks did not differ significantly between taribavirin (38%, 42%, and 49% for the 800, 1200, and 1600 mg groups) and ribavirin (49%). The highest proportion of patients with undetectable HCV RNA at end of treatment and at follow-up occurred in both the taribavirin 1200mg QD (63% and 37%) and ribavirin groups (62% and 44%). SVR rates were 23%, 37% and 29% for taribavirin and 44% for ribavirin. Fewer patients on any dose of taribavirin had severe anemia (hemoglobin <10 g/dL) than on ribavirin (6/135 [4%] vs. 12/45 [27%]).
Conclusions: Given with interferon, taribavirin produced SVR rates comparable to those of ribavirin, with a lower occurrence of anemia.