Idenix Pharmaceuticals Inc and Novartis AG are codeveloping valopicitabine dihydrochloride, a once-daily oral nucleoside for the potential treatment of HCV infection. In January 2005, a phase IIa clinical trial comparing valopicitabine dihydrochloride with pegylated IFN in treatment-naive HCV patients was ongoing, in addition to a phase IIb trial in patients that had previously failed pegylated IFN and ribavirin combination therapy. In January 2006, an international phase III trial in treatment-refractory patients was planned for the first half of the year, with a phase III trial in treatment-naive individuals planned for the second half of the year.