Clinical course of patients with insufficient viral suppression during entecavir therapy in genotype C chronic hepatitis B

Abstract Background/Aims The clinical course of patients with insufficient virologic suppression diagnosed with chronic hepatitis B undergoing entecavir therapy is unclear. Methods We retrospectively investigated the long-term clinical outcomes of entecavir treatment for more than 12 months in 355 nucleos(t)ide-naïve chronic hepatitis B patients, particularly those with primary non-response or partial virologic response. Results The median duration of entecavir therapy was 40 months (range, 12–64 months). Virologic response was achieved in 315 patients (88.7%). One hundred forty-four (96.6%) of 149 HBeAg-negative patients achieved virologic response. Among 206 HBeAg-positive patients, 52 (25.2%) achieved HBeAg seroconversion. Virologic breakthrough was observed in 7 patients (2.0%). Of these 7 patients, 5 (1.4%) had genotypic resistance to entecavir. Primary non-response and partial virologic response were evident in 6 (1.7%) and 63 (17.7%) patients, respectively. During continuous prolonged entecavir therapy, virologic response of patients with primary non-response and partial virologic response was achieved in 6 (100%) and 28 (44.4%) patients, respectively. Conclusion The vast majority of chronic hepatitis B patients in this study achieved virologic response through prolonged entecavir therapy, with only 1.4% chance of viral resistance. Furthermore, all patients with primary non-response were able to achieve virologic response without adjustment of antiviral therapy.