A Single-arm Study Evaluating the Efficacy and Safety of Telbivudine With or Without add-on Tenofovir in Adults With HBeAg-positive Chronic Hepatitis B (CHB)

All patients receive 600 mg/day, oral telbivudine for 24 weeks. Patients with non-detectable HBV DNA continue 600 mg/day, oral telbivudine for the remaining treatment period (Sub-group 1) Patients with detectable HBV DNA receive 300 mg/day, oral tenofovir plus 600 mg/day, oral telbivudine for the remaining treatment period (Sub-group 2)