The addition of SciClone's Zadaxin to pegylated interferon alpha treatment in hepatitis C (HCV) patients has failed to produce a significant benefit over pegylated interferon alone in a Phase III trial, the company reported.

The trial evaluated the effect of the drug combination in treatment of hepatitis C patients with early cirrhosis of the liver who failed prior therapy. Addition of Zadaxin failed to produce an improvement in sustained virologic response, the trial's primary endpoint.

Zadaxin was generally well-tolerated with no treatment-related toxicities or side effects. In December 2005, the company reported final results from its first U.S. Phase III HCV trial, which were consistent with these results and not statistically significant.