This trial is to assess the efficacy and safety of Polyethylene Glycol thymosin alpha1 (PEG-Tα1), a new long immunomodulator (Category 1.1 of Chemical Drugs) being developed from Hansoh Pharmaceutical of China, in combination with adefovir in HBeAg-positive patients with chronic hepatitis B.

A total of 116 HBeAg-positive patients were recruited from 12 hospitals in China, and randomized to two groups. The combination group (n= 57) received PEG-Tα1 (1.6 mg/ml, once a week, taken subcutaneously) and adefovir (10 mg, once daily, taken orally) for 24 weeks. The control group (n = 59) received placebo and adefovir. Both groups received adefovir continuously for additional 24 weeks. The primary endpoint was the loss of HBeAg at 48 weeks. The secondary endpoints included 1) loss of hepatitis B virus ( HBV) DNA, 2) HBeAg seroconversion and 3) alanine aminotransferase (ALT) normalization etc. at week 4, 12, 24, 36 and 48. The number of CD4＋and CD8＋T cells was also determined during 48 weeks.