A six-month trial comparing thymosin alpha-1 with interferon-alpha for chronic hepatitis B found that thymosin alpha-1 produced increasingly strong results over time, with 48.3% achieving complete response by six months post-treatment versus 27.3% for interferon. Thymosin alpha-1 was also better tolerated with no side effects and showed three-fold better odds of normalizing liver function and clearing viral DNA during follow-up.
Abstract
AIM: To observe the efficiency and safety of thymosin-alpha1 treatment in patients with hepatitis B e antigen (HBeAg) and HBV DNA positive chronic hepatitis.
METHODS: Sixty-two patients were randomly divided into groups A and B. The patients in group A received subcutaneous injection of 1.6 mg thymosin-alpha1, twice a week (T-alpha1 group) for six months, and the patients in group B received 5 MU interferon alpha (IFN-alpha) each day for fifteen days, then three times weekly (IFN-alpha group) for six months. The results between two groups treated with and the group untreated with IFN-alpha which was followed up for 12 mo (historical control group consisting of 30 patients) were compared, and three groups were comparable between each other (P>0.05) at baseline (age, sex, clinical history, biochemical, and serological parameters).
RESULTS: At the end of treatment, complete response, which was defined as alanine aminotransferase (ALT) normalization and HBV DNA and HBeAg loss, occurred in 9 of 29 (31.0%) patients in the T-alpha1 group and in 15 of 33 (45.5%) patients in the IFN-alpha group (chi2=1.36, P>0.05). After a follow-up period of six months, a complete response was observed in 14 of 29 (48.3%) patients in the T-alpha1 group and in 9 of 33 (27.3%) patients in the IFN-alpha group (chi2=2.93, P>0.05). Compared with the results observed in the historical control (HC) group untreated with IFN-alpha which was followed up for 12 mo, the rate of complete response was significantly higher in IFN-alpha group at the end of therapy (1 of 30 vs 15 of 33, chi2=14.72, P<0.001) and in the T-alpha1 group at the end of follow-up (1 of 30 vs 14 of 29, chi2=15.71, P<0.001). In T-alpha1 and IFN-alpha treatment groups, the area under (the plasma concentration time) curve (AUC) of negative HBV DNA and HBeAg was 34%, 17%, 31% and 19% smaller than that in the HC group. By the end of the follow-up period, the proportions of ALT normalization and negative HBV DNA in the T-alpha1 group were significantly higher than those in the IFN-alpha and HC groups. The odds of ALT normalization and negative HBV DNA at the end of the follow-up was three-fold higher in the T-alpha1 group than in the IFN-alpha group. Unlike IFN-alpha, T-alpha1 was well tolerated by all patients, and no side effects appeared in T-alpha1 group.
CONCLUSION: The results suggest that a 6-mo course of T-alpha1 therapy is effective and safe in patients with chronic hepatitis B. T-alpha1 is able to reduce HBV replication in patients with chronic hepatitis B. Furthermore, T-alpha1 is better tolerated than IFN-alpha and can gradually induce more sustained ALT normalization and HBV DNA and HBeAg loss. However, a response rate of 48.3% is still less ideal. A more effective therapeutic approach warrants further study.