The current analysis evaluated nucleoside-naive patients from two phase 3 entecavir studies [hepatitis B e antigen (HBeAg)-positive (ETV-022) and HBeAg-negative (ETV-027)] who subsequently entered an open-label rollover study (ETV-901) and received entecavir for a total duration of at least 3 years. During the phase 3 program, patients

received 0.5 mg of entecavir daily, and during the long-term rollover study, all patients received 1.0 mg of entecavir daily. Some patients received concurrent lamivudine (100 mg daily) for a brief period of time early in the rollover study before they continued on entecavir monotherapy (1.0 mg daily) after the protocol MI-503 solubility dmso was amended. Patients and investigators could discontinue entecavir therapy in the rollover study at any time, and patients who discontinued therapy were to be followed for 24 weeks to assess safety. The study protocol

was approved by the ethics committees at all participating institutions, and written, informed consent was obtained from all patients. The study was carried out in accordance with the ethics principles of the Declaration of Helsinki and was consistent with good clinical practice guidelines and local regulatory requirements. Complete inclusion criteria for enrollment in the ETV-022 (HBeAg-positive) and ETV-027 (HBeAg-negative) studies have been described previously.21, 22 Some key inclusion criteria were as follows: age GSK-3 inhibitor ≥16 years; serological diagnosis of CHB; compensated liver function; absence of coinfection with hepatitis C, hepatitis D, or human immunodeficiency virus; no more than 12 weeks of prior lamivudine therapy; and no use of interferon-α, thymosin-α, or antiviral agents with anti–hepatitis B activity within

tuclazepam 24 weeks of randomization. A total of 293 nucleoside-naive patients treated with entecavir in the two pivotal phase 3 studies (ETV-022 and ETV-027) were enrolled into the ETV-901 long-term rollover study (Fig. 1). Of these 293 patients, 69 (24%) consented to undergo long-term liver biopsy (the long-term histology cohort). The primary reasons for not performing long-term liver biopsy in the 224 patients not part of the long-term histology cohort were as follows: (1) the patient was off study (44%), (2) the patient refused consent (33%), or (3) the investigator chose not to participate in the amended study (17%). Liver biopsy was performed at the baseline and again after 48 weeks of blinded entecavir therapy in the phase 3 studies. In the long-term rollover study, optional liver biopsy was offered at two time points: after an additional 48 weeks of treatment in the rollover study and after a protocol amendment for patients who had received at least 3 years of cumulative entecavir therapy.