Purpose Entecavir demonstrated superior virologic and biochemical benefits over lamivudine at 48 weeks in nucleoside-naïve Chinese patients with chronic hepatitis B (CHB). We evaluated the effect of continued entecavir and lamivudine treatment in patients who continued treatment in year 2 and the off-treatment durability of patients who achieved a protocol-defined consolidated response at week 48. Methods Chinese adults (n = 519) with CHB were randomized to a minimum of 52 weeks of treatment with entecavir 0.5 mg/day or lamivudine 100 mg/day. Patients with a consolidated response at week 48 (HBV DNA \0.7 MEq/ml for C24 weeks, ALT \1.25 times ULN, and, if HBeAg(?) at baseline, loss of HBeAg for at least 24 weeks) stopped treatment at week 52 and were followed off-treatment. Patients with a partial response at week 48 (HBV DNA \0.7 MEq/ml in the absence of other criteria for a consolidated response) could continue blinded treatment for up to 96 weeks. Patients were assessed for HBV DNA, ALT normalization, safety, and, if HBeAg(?) at baseline, for HBe seroconversion. Cumulative proportions of all treated patients who ever achieved these responses were also analyzed. Results Among patients treated during year 2 (entecavir: n = 193; lamivudine: n = 145), 74% of entecavir-treated