SciClone’s European partner, Sigma-Tau, is conducting a large, multi-center phase 2 trial in Europe evaluating different dose levels of ZADAXIN in combination with dacarbazine chemotherapy (DTIC) with and without interferon alpha for the treatment of malignant melanoma.  Patients enrolled in this trial have stage IV malignant melanoma, which is the most advanced and imminently fatal form of the disease. Enrollment has been completed with over 450 patients enrolled. The trial is comprised of five separate treatment arms:

1. DTIC plus low-dose interferon alpha (control arm)
2. ZADAXIN (1.6 mg) plus DTIC plus low-dose interferon alpha
3. ZADAXIN (3.2 mg) plus DTIC
4. ZADAXIN (3.2 mg) plus DTIC plus low-dose interferon alpha
5. ZADAXIN (6.4 mg) plus DTIC plus low-dose interferon alpha

In December 2005, SciClone reported interim overall tumor response data (according to RECIST criteria) from 270 of 320 patients who have been enrolled in the first four treatment arms. These interim results showed a distinct ZADAXIN dose-dependent response in combination with dacarbazine chemotherapy (DTIC) with and without low-dose interferon alpha. Additional tumor response data from all patients as well as early survival information on the first 320-patient cohort are expected in the second half of 2006. Sigma-Tau and SciClone intend to share these data with the FDA and EMEA in order to discuss plans for phase 3 trials.

Specifically, results reported in December 2005 showed that in each of the three treatment arms that included ZADAXIN, a higher overall tumor response rate was observed as compared with the control arm. Overall tumor response was achieved by 12.9% of the patients treated with 3.2 mg of ZADAXIN in combination with DTIC, compared with only 3.9% of patients in the control arm. Furthermore, the addition of ZADAXIN to DTIC and low-dose interferon alpha provided a greater overall tumor response in a dose-related fashion. 7.4% of patients who were treated with 1.6 mg of ZADAXIN, DTIC and low-dose interferon alpha achieved an overall response, and 10.9% of patients who were treated with 3.2 mg of ZADAXIN, DTIC and low-dose interferon alpha achieved an overall response. The adverse events observed to date in this trial are consistent with those expected for this group of patients treated with DTIC and interferon alpha.

Also in December 2005, SciClone reported results from its small, proof-of-concept liver cancer trial conducted to evaluate ZADAXIN’s effectiveness in combination with trans-arterial chemoembolization (TACE). A trend toward positive survival benefit was observed in patients treated with ZADAXIN plus TACE compared with patients treated with TACE alone, the control arm. Specifically, a median survival of 994 days was observed for the 12 patients who received ZADAXIN plus TACE, compared with a median survival of only 399 days for the 13 patients who received TACE alone. No difference was observed in tumor response between the treatment groups.

SciClone believes that developing ZADAXIN for malignant melanoma is the most expeditious route toward achieving U.S. or European regulatory approval for a cancer indication.