Low hepatitis B envelope antigen seroconversion rate in chronic hepatitis B patients on long-term entecavir 0.5 mg daily in routine clinical practice

Abstract

Data from registration trials with highly selective patients have shown that hepatitis B envelope antigen (HBeAg)-positive patients with chronic hepatitis B respond well to entecavir (ETV) 0.5 mg daily, with an HBeAg seroconversion rate of 21% at 12 months. However, there are varying data on the treatment outcomes of ETV 0.5 mg daily in routine clinical settings, with seroconversion rates at 12 months ranging from 8 to 48% in studies limited to 44-90 patients from centers in Asia, Europe, and South America. In the present study, we examined long-term treatment efficacy and tolerability in 136 consecutive treatment-naive HBeAg-positive chronic hepatitis B patients treated between January 2005 and January 2011 with ETV 0.5 mg daily at community clinics and tertiary centers in the USA. The primary study end point was HBeAg seroconversion. Sixty-one percent of HBeAg-positive patients were men, mean age 39 ± 12 years, median hepatitis B virus DNA 7.48 (3.7-9.8) log10 IU/ml, median alanine aminotransferase 67 (14-1077) U/l, and median treatment duration 18 (6-60) months. At months 12, 24, and 36, complete viral suppression rates were 41, 66, and 85% and HBeAg seroconversion rates were 4.8, 20, and 30%, respectively. No patients experienced adverse events or developed genotypic resistance to ETV. In clinical settings, ETV is highly tolerable and potent at suppressing hepatitis B viremia; however, the rates of HBeAg seroconversion appear to be much lower than those reported, highlighting the importance of appropriate counseling and planning for long-term therapy.