Efficacy and Safety of Combination Therapy of Thymalfasin and Entecavir in HBeAg-positive ETV-experienced Patients

Inclusion Criteria: * HBsAg positive and anti-HBs negative for more than 6 months * Being currently treated with ETV ≥1 years * HBeAg positivity and HBV DNA \<60IU/mL with HBsAg \<1500IU/mL and HBeAg \<200S/CO at screening * ALT ≤5\*ULN and total bilirubin ≤2\*ULN * Age ≥ 18 yrs but ≤ 55 yrs * Written informed consent Exclusion Criteria: * Patients who have contraindications for Thymosin alpha 1 in accordance with the approved summary of product characteristics * Patients with ALT \> 5 x ULN or total bilirubin \>2\*ULN * Patients with evidence of hepatocellular carcinoma at screening * Patients with Child-Pugh score ≥7 or had a history of hepatic encephalopathy or esophageal pile or ascites * Patients with serological evidence of co-infection with hepatitis A virus, hepatitis C, human immunodeficiency virus or hepatitis D virus * Patients with a history of excessive drinking: male \>40g/d,female \>40g/d * Pregnant or breast-feeding women * A history of liver transplantation or planned for liver transplantation * Patients of autoimmune disease * Patients with other diseases combined * Patients with creatinine \>1.5\*ULN * Investigator considered not proper for participating the trial * Patients with other maliginant tumor