Quantification of HBsAg and HBV-DNA during therapy with peginterferon alpha-2b plus lamivudine and peginterferon alpha-2b alone in a German chronic hepatitis B cohort.

ABSTRACT

BACKGROUND: Peginterferon alpha-2b (PEG-IFNa2b) and lamivudine are efficient treatment options for chronic hepatitis B virus (HBV) infection. We assumed that a combination therapy of PEG-IFNα-2b plus lamivudine will be more effective than PEG-IFNα-2b alone concerning loss of HBV-DNA, HBeAg seroconversion, and HBsAg reduction. PATIENTS AND METHODS: Patients with chronic hepatitis B were randomised to nine months treatment with PEG-IFNα-2b 1.5 µg/kg o. i. w. or PEG- IFNα-2b plus lamivudine 100 mg/d. The study was designed with 60 patients per treatment arm. The primary endpoint was defined as loss of HBV-DNA (< 400 copies/mL) 24 weeks after the end of therapy. HBV-DNA (PCR), HBsAg (Architect, Abbott), and HBeAg (Axsym, Abbott) were determined prior to and at the end of treatment as well as at follow-up. HBV-genotypes were determined by Innolipa (Innogenetics). RESULTS: Only 32 patients were randomised to combination therapy and 27 individuals to monotherapy due to low recruitment rates. On treatment reduction of HBV-DNA was significantly higher during combination therapy compared to PEG-IFNa-2b monotherapy (- 4.60 ± 2.71 vs. - 2.41 ± 2.17 log; p = 0.003). However, there was no difference in the number of cases achieving HBV-DNA < 400 copies/mL, ALT normalisation, or HBeAg seroconversion at follow-up. None of the parameters was significantly related to HBV-genotypes. In a post-hoc analysis serum HBsAg levels were analysed as an additional prognostic parameter for treatment response (n = 29). Combination therapy showed a stronger, but not significant HBsAg decline during (- 0.7 ± 1.17 log IU/mL vs. - 0.26 ± 0.61 log IU/mL; p = 0.35) and after therapy (- 0.68 ± 1.29 log IU/mL vs. - 0.24 ± 0.56 log IU/mL; p = 0.82). Two of three cases with a 2-log HBsAg decline to HBsAg levels < 100 IU/mL eliminated HBsAg during long-term follow-up. CONCLUSION: The study was underpowered with respect to the primary endpoint due to low recruitment rates. However, in the post-hoc analysis HBsAg decline was over two-fold stronger at the end of treatment and follow-up after combination therapy and did not rebound after lamivudine withdrawal. These results may indicate the usefulness of future combination therapies without discontinuation of nucleos(t)ide analogues.