Department of Hepatology, Toranomon Hospital, Tokyo, Japan.
BACKGROUND & AIMS:
We determined the antiviral potency and viral resistance rate after 4years of continuous entecavir treatment in patients with chronic hepatitis B (CHB) infection.
The cumulative rates of undetectable hepatitis B virus DNA (HBV DNA;<2.6 log(10) copies/ml), hepatitis B e antigen (HBeAg) seronegativity, seroconversion, alanine aminotransferase (ALT) normalization, and entecavir signature mutations were calculated in 474 nucleos(t)ide-naïve CHB patients (HBeAg-positive: 47%) on continuous entecavir treatment for 4years.
Median age was 47years and follow-up period was 2.4years, with 403, 281, 165, and 73 patients followed-up for at least 1, 2, 3, and 4years, respectively. Incremental increases were observed in the rates of undetectable HBV DNA, HBeAg seroclearance and seroconversion, and ALT normalization, reaching 96%, 42%, 38% and 93%, respectively, by the fourth year. In all, 100% and 93% of patients negative and positive for HBeAg, respectively, had undetectable HBV DNA at year 4. Of 165 patients, HBV DNA was detectable in nine patients after 3years. Multivariate analysis identified HBV DNA level (⩽7.6log(10) copies/ml, OR=15.8; 95% CI=43.1-79.9, P=0.001) as an independent predictor of undetectable HBV DNA at year 3. Five patients experienced virological breakthrough including two (0.4%) who developed entecavir-resistance mutations.
Continuous treatment of nucleos(t)ide-naïve CHB patients with entecavir over 4years was associated with 96% chance of undetectable HBV DNA and only 0.4% chance of emerging entecavir-resistant mutations.