1157 2′,3′-dideoxy-3′-fluoroguanosine (FLG) has antiviral activity against both wild type and lamivudine resistant hepatitis B virus in vitro: results of assays using the recombinant baculovirus system

Abstract

The development of antiviral-resistant mutations with long-term treatment remains a major concern in the treatment of chronic hepatitis B virus (HBV) infection. The study aimed to compare the therapeutic efficacy of entecavir 1 mg versus combined lamivudine/adefovir dipivoxil (Lam/Adv) in chronic HBV patients resistant to lamivudine monotherapy.This study included two groups of lamivudine-resistant patients who received lamivudine 100 mg for 1–3 years. Group 1 was composed of 25 cases (52% HBeAg+ve) who received combined Lam/Adv, and group 2 was composed of 13 patients (30.8% HBeAg+ve) who received entecavir 1 mg. Pre-enrolment assessment included biochemical, serological and quantitative HBV-DNA testing as well as HBeAg and hepatitis B envelope antibody (HBeAb) assessment. Evaluation was done at 3, 6, 12, 24 and 36 months of treatment by the same parameters. Hepatitis B surface antigen and antibody (HbsAg and HBsAb) were assessed after each year of treatment.At the end of 36 months of treatment, 16 cases (69%) in group 1 completed the study period, versus 13 (100%) in group 2. Two cases in group 1 underwent HBeAg seroconversion, accompanied by HBV-DNA undetectability, at 6 and 12 months, respectively; no cases were seroconverted in group 2. Both treatments achieved improvement in alanine aminotransferase (ALT), bilirubin and alpha-foetoprotein equally at the end of the study. HBV-DNA undetectability was better achieved in group 2 when compared to group 1. HBeAg seroconversion was only achieved in two cases in group 1, whereas no cases lost HBeAg in group 2. None of our cases achieved HbsAg seroconversion or loss at the end of the study period.The entecavir 1-mg monotherapy group achieved better HBV-DNA undetectability starting at 3 months of treatment when compared to the Lam/Adv group; however, both lines of treatment showed almost similar results over the rest of the study period. HBeAg seroconversion was only achieved in two cases in the combined Lam/Adv group, whereas no cases lost HBeAg in the other group.