SOURCE: SciClone Pharmaceuticals, Inc.

June 21, 2005 06:30 ET

SciClone Announces Zadaxin Hepatitis C Triple Therapy Poster Presentation

SAN MATEO, CA -- (MARKET WIRE) -- June 21, 2005 -- SciClone Pharmaceuticals, Inc. (NASDAQ: SCLN) today announced the poster presentation of additional data evaluating its lead product candidate ZADAXIN® (thymosin alpha 1), in combination with pegylated interferon alpha and ribavirin, as a potential treatment for the hepatitis C virus (HCV) at the Congress of the Mexican Association of Hepatology annual conference. Data reported in this presentation includes a full 72-week analysis of 30 HCV non-responder patients enrolled in this pilot trial and builds on the results reported on 25 of these patients in November 2004 at the American Association for the Study of Liver Disease (AASLD).

Of the thirty patients evaluated at week 72, at which point patients have completed 48 weeks of triple therapy of ZADAXIN, pegylated interferon alpha and low-dose ribavirin and 24 weeks of follow-up observation, 20% (6/30) achieved a sustained viral response (SVR). SVR is defined as the absence of HCV RNA in the bloodstream, measured by PCR test, at 72 weeks. Of the twenty six patients in this group infected with the difficult-to-treat genotype 1 strain of HCV, 23% (6/26) achieved an SVR. By comparison, a separate, unrelated trial reported only 9% of genotype 1 patients achieved SVR after retreatment with pegylated interferon alpha and a similar dose of ribavirin.

"We are pleased to report that the response rate observed in this additional data is consistent with the response we previously reported from the 25 patient cohort in this small pilot trial. While these data are encouraging, data from the large, ongoing phase 3 triple therapy clinical trial, being conducted by our European partner Sigma-Tau, should be more predictive of ZADAXIN's use as part of triple therapy," said Ira D. Lawrence, M.D., President and Chief Executive Officer of SciClone Pharmaceuticals, Inc. "Importantly, we look forward to reporting results in the early part of 2006 from our U.S. phase 3 HCV trials using ZADAXIN in combination with pegylated interferon alpha, currently considered to be the cornerstone of therapy."

All patients enrolled in this pilot trial were non-responders to prior HCV therapy and are Hispanic, a population that is suggested to be less likely to respond to therapy independent of genotype. In addition, most of the patients enrolled were infected with the genotype 1, widely considered to be the most difficult-to-treat strain of HCV in the general population. Genotype 1 infected carriers account for 70% of the 2.7 million chronic carriers of HCV in the United States.

About the Triple Therapy Pilot Trial

The triple therapy pilot trial evaluating ZADAXIN in combination with pegylated interferon alpha and low-dose ribavirin is being conducted by a team led by Dr. Jorge L. Poo, Chief Scientific Officer of CIF-Biotech at the Medica Sur Hospital in Mexico City. This trial is being funded by Laboratorios Columbia, SciClone's licensee in Mexico, a market where ZADAXIN is approved for the treatment of HCV. The following table summarizes the response rates at the end of the follow-up observation period:

Summary of Results                   Week 72(1)
                                        SVR
                        Intent-to-Treat       Per Protocol

All non-responders        20% (6/30)           21% (6/28)
Genotype 1                23% (6/26)           25% (6/24)

(1) HCV RNA negative by PCR test
Using an intent-to-treat analysis, 20% (6/30) of all patients and 23% (6/26) of the genotype 1 patients achieved an SVR. Using a per protocol analysis, which excludes the 2 patients who dropped therapy by week 24 due to adverse side effects from pegylated interferon, 21% (6/28) of all patients and 25% (6/24) of genotype 1 patients achieved an SVR. All of the patients who achieved an SVR were infected with genotype 1 and had failed previous combination therapy of interferon plus ribavirin.

This small, open label, single-arm pilot trial enrolled 40 patients infected with HCV, none of whom had responded to previous treatment with standard therapy. All patients are Hispanic, 39 were non-responders to prior therapy of interferon plus ribavirin and the other non-responder had previously been treated with interferon alone. Thirty patients have completed the treatment and follow-up period, eight have completed the treatment but not the follow-up period, and an additional two patients are still undergoing treatment.

Patients received 48 weeks of therapy of a standard dose of ZADAXIN (1.6 mg/twice-weekly), a standard dose of pegylated interferon alfa-2a (180 mcg/week), and a low dose of weight-based ribavirin (800 - 1,000 mg/day). At the end of 48 weeks of therapy, patients were observed for 24 weeks to determine SVR at week 72, the trial endpoint. During the course of therapy, 24% (9/38) of patients required a dose reduction of pegylated interferon, 18% (7/38) required a dose reduction of ribavirin and none required a dose reduction of ZADAXIN. As in all previous ZADAXIN studies, the safety profile was excellent without any reports of significant ZADAXIN related side effects or toxicities.

About SciClone's Ongoing Hepatitis C Trials

Non-responders to previous hepatitis C therapy are the subjects of SciClone's two U.S. phase 3 clinical trials for ZADAXIN in combination therapy with pegylated interferon. These trials enrolled over 1,000 patients and SciClone expects to report data in the early part of 2006. As previously announced, SciClone's European partner Sigma-Tau is enrolling non-responders in a 550-patient phase 3 HCV triple therapy trial using the current standard dose of ribavirin (1,000 - 1,200 mg/day), which is about 20% higher than the dose of ribavirin used in this pilot trial. SciClone's objective for the European trial is to generate data on ZADAXIN's use as part of a triple therapy combination for hepatitis C patients.

About SciClone

SciClone Pharmaceuticals is a biopharmaceutical company engaged in the development of therapeutics to treat life-threatening diseases. SciClone's lead product ZADAXIN is currently being evaluated in two phase 3 hepatitis C clinical trials in the United States and one phase 3 hepatitis C trial in Europe. ZADAXIN is also being evaluated in other late-stage clinical trials for the treatment of hepatitis B and certain cancers. The company's other drug development candidate is SCV-07, a potential IND candidate that is currently being evaluated in pre-clinical studies for the treatment of viral and other infectious diseases. For more information about SciClone, visit www.sciclone.com.

The information in this press release contains forward-looking statements including our expectations and beliefs regarding the progress of the triple therapy hepatitis C clinical trial and other clinical trials, and the fact that the experimental or clinical data described may imply certain actual results in larger patient populations. Words such as "expects," "plans," "believe," "may," "will," "anticipated," "intended" and variations of these words or similar expressions are intended to identify forward-looking statements. In addition, any statements that refer to expectations, projections or other characterizations of future events or circumstances, including any underlying assumptions, are forward-looking statements. These statements are not guarantees of future performance and are subject to risks, uncertainties and assumptions that are difficult to predict. Therefore, our actual results could differ materially and adversely from those expressed in any forward-looking statements as a result of various factors, including the fact that experimental data and clinical results derived from studies with a limited group of patients may not be predictive of the results of larger studies, interim data may not be predictive of clinical trial results, the progress or failure of the triple therapy hepatitis C clinical trial and other clinical trials, competition for enrollment of patients meeting a particular patient profile, maintenance of the sufficiency and eligibility of the enrolled patient population and unexpected adverse results to patients, as well as other risks and uncertainties described in SciClone's filings with the Securities and Exchange Commission.

Contact Information

  • Corporate contact:
    Becky Horner
    Investor Relations
    SciClone Pharmaceuticals, Inc.
    650-358-3437