Entecavir 1 mg is commonly used in patients with chronic hepatitis B (CHB) patients with previous antiviral resistance. This study evaluates the efficacy and safety of switching to generic entecavir 1 mg (Baracle®, Dong-A Science Technology) in CHB patients taking brand name entecavir 1 mg (Baraclude®, Bristol-Myers Squibb) alone or in combination with other nucleos(t)ide analogues after the development of antiviral resistance.

The primary aim is virological response (<20 IU/mL) at 12 months

This study is a prospective single-arm open-label trial. The primary endpoint is virological response (<20 IU/mL) at 12 months after switching treatment.

Patients who satisfy the inclusion and exclusion criteria will switch from Baraclude® 1 mg to Baracle®. Assessment of treatment response at 12 months is performed by comparing undetectable HBV DNA rates between baseline and 12 months after switching therapy.

Inclusion Criteria:

• Age >19 years old CHB patients
• Confirmed antiviral resistance
• Taking brand entecavir 1 mg for more than 1 year
• HBV DNA < 20 IU/mL
• Compensated liver cirrhosis
• Willing to participate

Exclusion Criteria:

• Failure to meet the inclusion criteria
• Cr>1.5 mg/dL
• Postive HCV Ab
• Decompensated cirrhosis
• Pregnant women
• HCC
• Alcoholics