Safety and Antiviral Study of ACH126, 433 (b-L-Fd4C) in Adults With Lamivudine-resistant Chronic Hepatitis B

Inclusion Criteria * Chronic HBV infection, known to be hepatitis B surface antigen (HbsAg) positive ≥ 6 months * On lamivudine, either 100 or 150 milligrams daily for the treatment of chronic hepatitis B infection and exhibit a 2-3 log decrease in HBV deoxyribonucleic acid (DNA) levels followed by a rebound of at least 1.5 log HBV DNA or * Achieved an HBV DNA level of \< 10,000 copies/milliliter (mL) HBV DNA on at least 2 occasions and have rebounded to \> 100,000 copies/mL HBV DNA, or * Have a demonstrable lamivudine -resistant genotype regardless of treatment history. * Hepatitis B e-antigen positive. * Human immunodeficiency virus (HIV) negative. * Serum alanine aminotransferase ≥ 1.5 and ≤ 10x times the upper limit of normal (ULN). * Hemoglobin ≥ 10 grams/deciliter or hematocrit ≥ 30% (in the absence of blood transfusions or erythropoietin treatment in the preceding 2 weeks). * Platelet count \>75,000/cubic millimeters (in the absence of ongoing granulocyte colony-stimulating factor therapy). * Serum creatinine \< 1.1x the ULN. * Negative radiologic screening test (ultrasound, computerized tomography scan, or magnetic resonance imaging) for hepatocellular carcinoma within 6 months prior to entry. * Prothrombin time/international normalize ratio \< 2. * Participants of reproductive capability must utilize an approved form of birth control. * All women of child-bearing capability must have a negative serum or urine pregnancy test (minimum sensitivity of 24 international units/liter of beta human chorionic gonadotropin) within 72 hours prior to the start of study medication. * Participants must be able to provide written informed consent. * Participant must be available for follow-up for a period of 20 weeks. Exclusion Criteria * HIV infection. * Hepatitis C co-infection. * Alcohol abuse. * Pregnancy or breast-feeding. * Inability to tolerate oral medication. * Any clinical condition or prior therapy that, in the Investigator's opinion, would make the participant unsuitable for the study or unable to comply with the dosing requirements. * Use of any investigational drug. * Participants with decompensated liver disease. * Use of any concomitant herbal treatments.