Adefovir-resistant HBV
����In patients with no prior exposure to other NA, lamivudine, telbivudine
or entecavir may be added. Alternatively, stop adefovir and use
tenofovir plus lamivudine or emtricitabine. (III)
����In patients with prior lamivudine resistance in whom lamivudine had
been stopped when treatment was switched to adefovir, stop adefovir
and use tenofovir plus lamivudine, emtricitabine (II-2) or entecavir (III),
but the durability of response to this combination is unknown.
Entecavir-resistant HBV
����Use adefovir or tenofovir since they have been shown to have activity
against entecavir-resistant HBV in in vitro studies, but clinical data are
lacking. (II-3)
Table 4. Definition of Response to Antiviral Therapy of
Chronic Hepatitis B
Category of Response
Biochemical (BR)
Decrease in serum ALT to within the normal range
Virologic (VR)
Decrease in serum HBV DNA to undetectable levels
by PCR assays, and loss of HBeAg in patients who were
initially HBeAg positive
Primary nonresponse ���
(not applicable to interferon
therapy)
Decrease in serum HBV DNA by < 2 log10 IU/mL after
at least 24 weeks of therapy
Virologic relapse
Increase in serum HBV DNA of 1 log10 IU/mL
after discontinuation of treatment in at least two
determinations more than 4 weeks apart
Histologic (HR)
Decrease in histology activity index by at least 2 points
and no worsening of fibrosis score compared to pretreatment liver biopsy
Complete (CR)
Fulfill criteria of biochemical and virological response
and loss of HBsAg
On-therapy
During therapy
Maintained
Persist throughout the course of treatment
End-of-treatment
At the end of a defined course of therapy
Off-therapy
After discontinuation of therapy
Sustained (SR-6)
6 months after discontinuation of therapy
Sustained (SR-12)
12 months after discontinuation of therapy
Time of Assessment
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