Results of up to 2 years of entecavir vs lamivudine therapy in nucleoside-naïve HBeAg-positive patients with chronic hepatitis B

Entecavir is a potent inhibitor of hepatitis B virus (HBV) polymerase. The efficacy and safety of entecavir in nucleoside-naïve patients with hepatitis B virus e antigen (HBeAg)-positive chronic hepatitis B was established in a large, international, double-dummy study (ETV-022) where patients were randomized to entecavir 0.5 mg/day (n = 354) or lamivudine 100 mg/day (n = 355) once daily. ETV-022 had a 52-week blinded treatment phase, followed by an extended blinded treatment phase for up to 44 additional weeks (96 weeks total). Treatment was discontinued for patients achieving a protocol-defined response as determined by patient management criteria that intended to test the possibility of finite therapy, which has not previously been studied for entecavir or other anti-HBV agents in a large trial. Early results from this study have been previously presented/published separately. This paper compiles the results of up to 2 years of treatment for protocol-defined responders, virologic responders and nonresponders. For responders who discontinued therapy (per protocol), 24-week off-treatment evaluation is presented to provide a more 'complete picture' of what clinicians can expect when treating nucleoside-naïve HBeAg-positive patients with chronic hepatitis B. For patients who discontinued therapy because of nonresponse (nonresponders) and subsequently entered the rollover study ETV-901, follow-up results, including resistance profile, are provided.