Decline in hepatitis B surface antigen levels with entecavir treatment in HBeAg-positive nucleoside naive chronic hepatitis B patients-results from phase III study ETV-022

Abstract

BACKGROUND: Entecavir (ETV) 0.5 mg demonstrated superior virologic, histologic, and biochemical benefit compared to lamivudine in phase III study ETV-022. Through 96 weeks of treatment and 24 weeks post-treatment follow-up, 5% of the patients achieved HBsAg loss. We present the changes in quantitative HBsAg levels in patients with HBeAg-positive nucleoside naive chronic hepatitis B patients treated with ETV in study ETV-022. METHODS: The nucleoside-naive HBeAg-positive patients received ETV 0.5mg daily in study ETV-022. HBsAg levels were assessed qualitatively and quantitatively every 12 weeks. The quantitative HBsAg levels were measured with the Abbott Architect Assay. Mean HBsAg levels were calculated at baseline, week 12, 24, 36 and 48 for the overall cohort and cohorts with HBeAg loss or HBsAg loss. RESULTS: A total of 95 ETV-treated patients from study ETV-022 had available blood samples and were analyzed for quantitative HBsAg levels. Baseline characteristics of patients include mean age 38 years old, mean HBV DNA 9.64 log10 copies/mL and ALT 156.65 U/L. The quantitative HBsAg levels over time in different patient groups are shown below. CONCLUSION: Quantitative HBsAg levels decreased overtime during the first 48 weeks of ETV therapy in HBeAg-positive nucleoside naive patients. A greater decline in quantitative HBsAg value was observed among subjects who had HBeAg loss or HBsAg loss.