The efficacy of tenofovir DF monotherapy versus FTC plus tenofovir DF combination therapy was evaluated for suppression of the virus (decrease in HBV DNA), serological response (generation of antibodies to the virus), biochemical response (changes in liver enzymes), and the development of drug-resistant mutations. The safety and tolerability of both tenofovir DF monotherapy and FTC plus tenofovir DF were evaluated by routine monitoring for adverse events and changes in laboratory parameters.