SciClone Pharmaceuticals, Inc. reported positive data from a pilot clinical trial in hepatitis C patients who have not responded to previous therapy. 41per cent of the non-responder patients tested HCV RNA negative and 50per cent showed a virologic response after 24 weeks of a new triple therapy of Zadaxin in combination with pegylated interferon alpha and ribavirin. By comparison, separate recent studies show that after 24 weeks of double therapy with pegylated interferon alpha plus ribavirin, approximately 30per cent of hepatitis C non-responder patients tested HCV RNA negative.
Dr Eduardo Martins, vice president of Medical Affairs of SciClone, commented, "As we continue to explore ways to further improve therapy options for the nearly half of hepatitis C patients that do not respond to the current standard of care, we are pleased to see Zadaxin used in combination with standard dose pegylated interferon and low dose ribavirin has improved response rates in this patient group without adding toxicity. Building on these data, we are closely monitoring the progress of this trial and are considering future triple therapy studies. Our primary focus remains our two ongoing US phase 3 clinical trials targeting Zadaxin in combination with pegylated interferon alpha to be the first FDA approved therapy to specifically address the needs of non-responders."
This ongoing trial plans to enroll a total of 50 hepatitis C non-responder patients, none of which have responded to prior therapy of at least six months of interferon alpha in combination with ribavirin. During the course of this study, patients will receive 12 months of triple therapy and will be observed for six months after completing therapy to measure sustained response, defined as negative HCV RNA by PCR test measured at week 72.
Of the 22 patients who completed 24 weeks of triple therapy of Zadaxin in combination with pegylated interferon alpha and ribavirin, 41per cent tested negative for HCV RNA by PCR test and 50per cent showed a virologic response to therapy, defined as a 2 log or greater reduction in the level of HCV RNA. Of the 19 patients infected with the difficult to treat HCV genotype 1, 42per cent tested negative for HCV RNA and 58per cent showed a virologic response to therapy. The safety profile was excellent without significant Zadaxin related side effects or toxicities.
In October 2003, SciClone reported 12 week interim data. After 12 weeks of triple therapy, 61per cent of hepatitis C non-responder patients reported an early virologic response, or EVR, defined as a 2 log or greater reduction in the level of HCV RNA, and 48per cent tested negative for HCV RNA. Of the 20 patients infected with the difficult to treat HCV genotype 1, 60per cent reported an EVR and 50per cent tested negative for HCV RNA.
During the course of this pilot clinical trial, patients will receive 12 months of triple therapy of a standard dose of Zadaxin (1.6 mg/bi-weekly) plus a standard dose of pegylated interferon alfa-2a (180 mcg/week) and a low dose of ribavirin (800-1,000 mg/day) and will be observed for six months after completing therapy to measure sustained response. The primary endpoint of the study is negative HCV RNA by PCR test measured at weeks 48 and 72. The secondary endpoints are normalization of ALT (a liver enzyme) measured at weeks 48 and 72 and reduction in HCV load measured at weeks 12, 24, 48, and 72.