SCICLONE AND SIGMA-TAU FILL SPOTS FOR PHASE III HEPATITIS C TRIAL
SciClone Pharmaceuticals and its European partner Sigma-Tau Dec. 28 announced that full patient enrollment is complete for its Phase III clinical trial evaluating the use of Zadaxin in combination with pegylated interferon alpha and ribavirin to treat patients infected with the hepatitis C virus (HCV). This trial is being conducted by Sigma-Tau in Europe and has enrolled a total of 553 patients.
The Phase III, multi-center, double-blinded, randomized study enrolled 553 predominately genotype 1 HCV patients who have not responded to previous treatment with pegylated interferon alpha and ribavirin. Patients have been randomized to receive either Zadaxin (thymalfasin or thymosin alpha 1) or a placebo, and all patients are receiving pegylated interferon alfa-2a and ribavirin. After completing 48 weeks of treatment, patients will be monitored for a 24-week observation period. The primary endpoint is sustained virological response, defined as the absence of HCV RNA measured at week 72, the end of the 24-week observation period. Data from this trial are expected to be publicly announced by year-end 2008.
Zadaxin is SciClone's brand of a pure synthetic preparation of thymalfasin, a substance which circulates in the blood naturally. Thymalfasin has been shown to activate various arms of the immune system, leading to an increase in expression of MHC Class I receptors to allow the immune system to recognize virally infected cells, a decrease in apoptosis or cell death of white blood cells, and an enhancement of the T helper 1 (Th1) subset of T cells by increasing the production of the Th1 cytokines INF-gamma and IL-2.
Zadaxin has been approved for sale by the ministries of health in over 30 countries and is marketed in China and selected other countries outside the U.S. and in combination with anti-viral and anticancer drugs, without any reported significant Zadaxin-specific side effects or toxicities.