SAN MATEO, CA -- (MARKET WIRE) -- 12/14/2005 -- SciClone Pharmaceuticals, Inc. (NASDAQ: SCLN) today announced top-line results from the first of its two phase 3 clinical trials using ZADAXIN® (thymalfasin) in combination with pegylated interferon alpha to treat patients with hepatitis C virus (HCV) who have failed previous interferon-based therapy. Treatment with ZADAXIN and pegylated interferon alpha did not demonstrate a statistically significant benefit compared to treatment with pegylated interferon alone in sustained viral response (SVR) or histologic improvement, the trial's co-primary endpoints. In this protocol, SVR was defined as the disappearance or absence of detectable HCV RNA in the bloodstream as measured by qualitative PCR test at the completion of a 48-week course of treatment and at week 72 the end of a 24-week observation period following completion of treatment. ZADAXIN was well tolerated with no treatment-related toxicities or side effects. SciClone will host a conference call at 9:00 a.m. ET today to review these clinical data.