Virological, serological and biochemical outcomes through 3 years of entecavir treatment in nucleoside-naive Chinese chronic hepatitis B patients

Hepatitis B virus (HBV) infection has a high prevalence in China. Entecavir has shown superior efficacy over lamivudine in Chinese nucleoside-naive chronic hepatitis B (CHB) patients over 48 weeks, with continued clinical benefit to 96 weeks. The present study evaluates the long-term efficacy of entecavir in Chinese CHB patients who continued entecavir treatment for 144 weeks. Patients receiving either entecavir 0.5 mg/day (n = 258) or lamivudine 100 mg/day (n = 261) entered the initial 96-week randomized, double-blind, controlled efficacy study. Patients who did not achieve a consolidated response [HBV DNA < 0.7 MEq/mL; alanine aminotransferase (ALT) < 1.25 x upper limit of normal; and if hepatitis B e antigen (HBeAg) positive at baseline, loss of HBeAg for >= 24 weeks] or who experienced viral breakthrough or relapse entered a 48-week entecavir rollover study. A total of 160 patients received continuous entecavir for 144 weeks; of these, 89% had undetectable serum HBV DNA, 86% showed ALT normalization, 20% reported HBeAg loss and 8% experienced HBeAg seroconversion. The cumulative rates of HBeAg loss and seroconversion were 36% and 27% at Week 144, respectively. The development of resistance was low, with three patients up to Week 96 and an additional two patients in Weeks 96-144 showing evidence of associated genotypic mutations. Entecavir was well tolerated. Adverse event rates were similar to those in lamivudine-treated patients, but patients receiving entecavir experienced fewer ALT flares. This study demonstrates that entecavir provides durable, long-term suppression of HBV DNA and ALT normalization in Chinese CHB patients, and is associated with low rates of emerging resistance. The results are consistent with the findings using entecavir globally and in Japan.