The purpose of this study is to determine the safety and antiviral activity of Clevudine, when retreated to patients previously treated with Clevudine

Inclusion Criteria:

1. Patients who received clevudine in L-FMAU-201 clinical trial (phase IIb)
2. Female of childbearing potential must have a negative serum ( b-HCG) pregnancy test within 14 days of starting therapy.
3. Patient is able to give written informed consent prior to study start and to comply with the study requirements.
4. Patients who met the following criteria after completion of the Week 48 visit were to have additional follow-up visits at Weeks 54 and 60: 1) had received no additional therapy since completion of 24-week treatment of clevudine and 2)experienced a > 1 log10 decrease from baseline in HBV DNA at Week 48

Exclusion Criteria:

1. HBV DNA negative (< 4,700 copies/mL) consistently at the last 2 visit (at least 2 consecutive visits, at one month interval)
2. Patient is currently receiving antiviral immunomodulatory or corticosteroid therapy.
3. Patients previously treated with lamivudine, lobucavir, adefovir or any other investigational nucleoside for HBV infection after cessation of treatment in L-FMAU-201 study.
4. Patient has a history of ascites, variceal hemorrhage or hepatic encephalopathy.
5. Patient is coinfected with HCV, HDV or HIV.
6. Patient with clinical evidence of cirrhosis or hepatocellular carcinoma (®-Fetoprotein) Evaluation will be based on alpha-fetoprotein primarily. If alpha-fetoprotein level is suggestive of cirrhosis or hepatocellular carcinoma, confirmation will be made with sonography etc.
7. Patient is pregnant or breast-feeding.
8. Patient is unwilling to use an "effective" method of contraception during the study and for up to 3 months after the use of study drug ceases. For males, condoms should be used. Females must be surgically sterile (via hysterectomy or bilateral tubal ligation), post-menopausal or using at least a medically acceptable barrier method of contraception (i.e., IUD, barrier methods with spermicide or abstinence)
9. Patient has a clinically relevant history of abuse of alcohol or drugs.
10. Patient has a significant gastrointestinal, renal, hepatic (decompensated), bronchopulmonary, neurological, cardiovascular, oncologic or allergic disease.
11. Patient has creatinine clearance less than 60mL/min as estimated by the following formula:

(140-age in years) (body weight [kg])/(72) (serum creatinine [mg/dL]) [Note: multiply estimates by 0.85 for women]