Any prior therapy with entecavir

At least 12 weeks of prior therapy with any nucleoside or nucleotide antiviral agent

Therapy with interferon alpha, thymosin alpha, or nucleototide antiviral agents within 24 weeks of screening

Coinfection with HIV, hepatitis C virus, or hepatitis D virus

Decompensated liver disease

Liver transplant recipients

Other forms of acute and chronic conditions which may cause increased ALT levels

Children who were breastfed while their mothers received lamivudine or whose mothers received lamivudine during pregnancy

A Phase III Study of the Safety and Efficacy of Entecavir in Pediatric Patients With Chronic Hepatitis B Virus Infection