Efficiency and Safety of an Early Dose Adjustment of Ribavirin in Patients Infected With Hepatitis C Underexposed to the Drug and Treated With Peginterferon Ribavirin.

Abstract

Ribavirin exposure after the first dose (D0AUC0-4h) >1755 mcg·h·L is predictive of sustained virological response (SVR) in patients with hepatitis C treated with peginterferon and ribavirin. The aim of this study was to test the benefit of ribavirin early dose adjustment based on this target in naïve patients infected with genotype 1. A multicenter randomized controlled trial with two parallel groups; fixed-dose (FD) group: standard of care in 2010-2011, ie, peginterferon-α2a 180 mcg·wk and weight-based ribavirin 1000-1200 mg/d during 48 weeks; adapted-dose (AD) group: increase of ribavirin dose if D0AUC0-4h <1755 mcg·h·L. A total of 221 patients were included, 110 in the AD group and 111 in the FD group with similar baseline characteristics. In the perprotocol analysis, SVR was higher in the AD group (55.1% versus 40.4%; P = 0.042), especially in patients with D0AUC0-4h <1755 mcg·h·L (54.3% versus 31.9%; P = 0.029). In the intention-to-treat analysis, the difference was not significant (50% versus 41%; P = 0.197). Ribavirin trough concentrations (C0s) at week 4 of treatment (intention-to-treat analysis) were higher in patients achieving SVR (2.06 versus 1.72 mg/L, P = 0.003). In the subgroup of patients with AUC0-4h <1755 mcg·h·L, 46% of patients with AD achieved a C0 >2.0 mg/L versus 22% of patients with FD (P = 0.013). Grade 1 anemia (but not other grades) was more frequent in the AD group (70% versus 48%, P = 0.001). The number of dose reductions or discontinuation of ribavirin was similar in both groups. Early ribavirin dose adjustment increases SVR in patients underexposed to ribavirin without increasing grade II-IV anemia. Such a strategy could be useful in patients with no access to new antiviral drugs.