Background: Treatment of chronic replicative hepatitis B virus (HBV) infection is aimed at stopping viral replication and preventing the development of chronic liver disease. beta-Interferon treatment has been less well studied than alpha-interferon.
Methods: The efficacy and tolerability of a 6-month course of subcutaneously administered human recombinant beta-interferon (rINF-beta ser) was studied and the results of a low-dose regime compared with a high-dose regime. Twenty patients (17 men and three women), aged 24-54 years, with chronic hepatitis B virus infection (all hepatitis B surface antigen-positive with detectable HBV-DNA in their sera for at least 3 months prior to therapy) were randomized into two treatment groups of 10 patients each. The low-dose group received 6 x 10(6) U/dose and the high-dose group received 30 x 10(6) U/dose, both groups receiving their respective doses three times a week initially for 1 month and continuing for a total of 6 months.
Results: The treatment was well tolerated in both groups. None of the patients required dosage reduction or cessation of treatment because of side-effects. HBV-DNA decreased in all patients during treatment, demonstrating the anti-viral efficacy of rINF-beta ser, and was undetectable in 20 and 40% of patients receiving low-dose and high-dose regimes, respectively, at the end of 6 months treatment (P = N.S.). One year after completion of treatment, HBV-DNA was undetectable in 50 and 30% of patients in the low-dose and high-dose groups, respectively (P = N.S.). However, only one patient achieved seroconversion with loss of the hepatitis B surface antigen and appearance of an antihepatitis B 'e' antigen at the end of 18 months.
Conclusion: This study shows that subcutaneously administered rINF-beta ser is well tolerated, but the optimal dose and duration of treatment still needs to be defined by further studies.