Entecavir, 0.5 mg daily, will have clinical efficacy (assessed as an undetectable hepatitis B DNA, <300 copies/mL, by Roche Comprehensive Bio-Analytical System Amplicor polymerase chain reaction assay) that is comparable (noninferior) and potentially superior to lamivudine, 100 mg once daily, in adults with hepatitis B e antigen-negative chronic hepatitis B virus infection.