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 463 HBeAg-positive patients were recruited from 33 hospitals in China, and randomized to two groups. The combination group received PEG-Tα1 (3.2 mg/ml, once a week, taken subcutaneously) and adefovir (10 mg, once daily, taken orally) for 48 weeks. The control group received placebo and adefovir. 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.

Inclusion Criteria:

• Chronic hepatitis B for more than 6 months, and didn't accept immunomodulating or anti-viral treatment within 6 months before the trial.
• ALT level > 2 × Upper Limit Normal (ULN).
• Serum bilirubin < 2 × ULN.
• Positive HBeAg and negative HBeAb.
• HBV-DNA between 1.00E＋05 IU/ml and 9.99E＋09 IU/ml.
• Informed Consent Form (ICF) signed.

Exclusion Criteria:

• Hepatitis A,C,D,E or HIV infection.
• Autoimmune hepatitis.
• Hepatic cirrhosis.
• Serum creatinine >1.5 × ULN or Ccr <50 ml/min, Haemoglobin <110g/L (male) or <100g/L (female), Platelet<80 E＋09/L, Serum albumin ≤ 35g/L, or Serum albumin/globulin (A/G) ≤0.9, Neutrophile granulocyte <1.0 E＋09/L, Prothrombin time>ULN＋3 seconds, Cholinesterase<4000U/L.
• Hepatitic carcinoma or Alpha Fetal Protein (AFP) >100ng/ml .
• Patients with other severe diseases combined, which could affect the therapy.
• Patients accepted other clinical trial within 6 months before the first administrated.
• Thymosin allergy.
• Pregnant or breast feeding.