Ribavirin Antagonizes the In Vitro Anti-Hepatitis C Virus Activity of 2'-C-Methylcytidine, the Active Component of Valopicitabine
Lotte Coelmont,1 Jan Paeshuyse,1 Marc P. Windisch,2 Erik De Clercq,1 Ralf Bartenschlager,2 and Johan Neyts1* Rega Institute for Medical Research, KULeuven, 3000 Leuven, Belgium,1 Department of Molecular Virology, University of Heidelberg, 69120 Heidelberg, Germany2
Received 27 March 2006/ Returned for modification 8 May 2006/ Accepted 31 July 2006
Ribavirin antagonizes the in vitro anti-hepatitis C virus (HCV) activity of the pyrimidine nucleoside analogue 2'-C-methylcytidine, the active component of the experimental anti-HCV drug valopicitabine. In contrast, the combination of ribavirin with either the purine nucleoside analogue 2'-C-methyladenosine or the HCV protease inhibitor VX-950 resulted in an additive antiviral activity. These findings may have implications when planning clinical studies with valopicitabine.