A pilot study of thymosin alpha1 therapy for chronic hepatitis B patients.

OBJECTIVE: The efficacy of thymosin alpha 1 (Talpha1) in patients with chronic hepatitis B still requires confirmation. We, therefore, evaluated the efficacy of therapy in patients with chronic hepatitis B. METHODS: Sixteen patients were randomly assigned into one of two groups, treated with 0.8 mg of Talpha1 (low dose group; n = 8) or 1.6 mg Talpha1 (high dose group; n = 8), administered six times weekly for two weeks, followed by twice weekly for another 22 weeks. Responders were defined as patients having clearance of hepatitis B e antigen by radioimmunoassay and negativity of hepatitis B virus (HBV)-DNA by branched DNA signal amplification and normalization of serum alanine aminotransferase (ALT) 24 months after initiation of Talpha1 therapy. Transient acute exacerbation was defined as an increase of more than 300 IU/I in serum ALT level during Talpha1 therapy. RESULTS: The response rate was 37.5% (6/16). Talpha1 therapy had a significant effect when, 1) transient acute exacerbation was present (p = 0.0029), 2) the serum HBV-DNA level was < 100 Meq/ml prior to the commencement of Talpha1 therapy (p = 0.0063). The difference between low and high dose groups was not statistically significant (p = 0.608). CONCLUSION: The results of this trial show that: 1) a 24-week course of Talpha1 could be a worthwhile strategy for chronic hepatitis B patients with a serum HBV-DNA level of less than 100 Meq/ml; and 2) patients with a transient acute exacerbation during Talpha1 therapy generally often respond well.