Five years of treatment with adefovir dipivoxil in Chinese patients with HBeAg‐positive chronic hepatitis B

AbstractBackgroundAdefovir dipivoxil (ADV) is a nucleotide analogue with proven efficacy in chronic hepatitis B (CHB).AimsThis study investigated long‐term ADV treatment in HBeAg‐positive patients.MethodsA total of 480 Chinese subjects with HBeAg‐positive CHB who participated in a 1‐year, double‐blind, placebo‐controlled study of ADV 10 mg daily were offered open‐label continuation for a further 208 weeks.ResultsA total of 390 subjects completed 5 years of treatment. Baseline median hepatitis B virus (HBV) DNA was 8.8 log10 copies/ml and alanine aminotransferase (ALT) 2.6 × upper limit of normal. Treatment with ADV resulted in sustained suppression of median HBV DNA by 4.8, 5.0, 5.1, 5.4 and 5.5 log10 copies/ml after 1, 2, 3, 4 and 5 years respectively. Continuous treatment with ADV led to a progressive increase in the proportion of subjects achieving undetectable HBV DNA, from 28% after 1 year to 58% after 5 years. HBeAg seroconversion rates increased cumulatively from 11% after 1 year to 29% after 5 years. HBsAg seroconversion was achieved by 1.0% of patients. ADV resulted in ALT normalization that was maintained throughout this study in 75–79% of subjects. Virological breakthrough associated with ADV resistant mutations (rtN236T and rtA181V) occurred in 14.6% of subjects. ADV was well tolerated.ConclusionFive years of ADV treatment in Chinese subjects with HBeAg‐positive CHB resulted in increasing virological and serological responses and sustained biochemical responses over time. Virological resistance was identified in 14.6% of patients. Urgent switch or add‐on therapy with a nucleoside analogue is necessary if ADV resistant mutations are detected, particularly rtN236T. Treatment was well tolerated.