Triple Therapy Pilot Trial

In a single-arm pilot trial evaluating the triple therapy of ZADAXIN, pegylated interferon alpha and ribavirin, 20% (6/30) of HCV non-responder patients achieved an SVR. These results are more than twice the 9% SVR from a separate, unrelated trial treating genotype 1 non-responder patients with pegylated interferon and a similar dose of ribavirin but without ZADAXIN.

The majority of the thirty patients enrolled in this pilot study were infected with the genotype 1 strain of HCV and are Hispanic, groups that are considered to be less likely to respond to current therapy.

U.S. Phase 3 Trials

Results from SciClone’s two phase 3 trials did not show a statistically significant benefit in sustained viral response (SVR). In the first trial, although not statistically significant, a positive ZADAXIN treatment-related trend was observed in SVR. In addition, patients who received ZADAXIN therapy were less likely to relapse, an occurrence where the virus reappears after previously being undetectable at the end of 48 weeks of treatment.

All patients in these trials had failed prior interferon-based treatment. In the first trial, more than 75% of patients were non-responders to the combination of interferon alpha (either regular or pegylated) and ribavirin and were infected with the genotype 1 strain of the virus. Additionally, most patients had a high viral load, or greater than 850,000 copies per ml (or 5.93 log10), of the virus.