This study will evaluate the efficacy and safety of peginterferon alfa-2a or ADV, in participants with lamivudine-resistant HBeAg-positive chronic hepatitis B. Participants will be randomized to receive either peginterferon alfa-2a for 48 weeks in combination with oral lamivudine for the first 12 weeks, or ADV for 72 weeks in combination with oral lamivudine for the first 12 weeks. The anticipated time on study treatment is 72 weeks, and the target sample size is 255 individuals.