Adding the peptide thymosin‑alpha‑1 to standard peginterferon treatment for hepatitis B did not make the therapy work better. The combined response rates were almost the same as using peginterferon alone, and side effects were similar.

Thymosin α-1 plus interferon α-2a offers superior efficacy over interferon α-2a alone in patients with chronic hepatitis B. The aim was to compare the antiviral efficacy of thymosin α-1 plus peginterferon α-2a and peginterferon α-2a alone in HBeAg-positive chronic hepatitis B patients. HBeAg-positive CHB patients were enrolled in this prospective, randomized, open-label study. Fifty-one patients were assigned to either combination (26 patients; 180 μg of peginterferon α-2a weekly for 48 weeks and 1.6 mg of thymosin α-1 twice a week for the first 12 weeks) or monotherapy (25 patients; 180 μg of peginterferon α-2a weekly for 48 weeks) groups. The rates of the combined response, defined as HBeAg seroconversion, HBV DNA suppression, and normalization of serum ALT, were 4/26 (15.4%) and 3/25 (12.0%) for the combination group and the monotherapy group at the end of treatment (p = 0.725), and 6/26 (23.1%) and 5/25 (20.0%) at the end of follow-up (p = 0.789), respectively. Based on multiple logistic regression analysis, a >2 log₁₀ IU/mL reduction of HBV DNA at week 12 was identified as an independent predictor for combined response (OR, 9.72; 95% CI, 1.33-71.06; p = 0.025) at the end of follow-up. A lower pretreatment HBV DNA level (≤ 7 log(10) IU/mL) was another predictor for combined response (OR, 9.64; 95% CI, 1.23-75.32; p = 0.031). No significant differences in adverse events were observed. The short-term addition of thymosin α-1 was not superior to peginterferon α-2a alone in HBeAg-positive CHB patients on the basis of antiviral efficacy.