Adefovir-resistant HBV
ÎIn 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)
ÎIn 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
ÎUse 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) Virologic (VR)
Primary nonresponse (not applicable to interferon therapy)
Virologic relapse Histologic (HR) Complete (CR)
On-therapy Maintained
End-of-treatment Off-therapy
Sustained (SR-6) Sustained (SR-12)
Decrease in serum ALT to within the normal range
Decrease in serum HBV DNA to undetectable levels by PCR assays, and loss of HBeAg in patients who were initially HBeAg positive
Decrease in serum HBV DNA by < 2 log10 at least 24 weeks of therapy
Increase in serum HBV DNA of 1 log10 IU/mL after
after discontinuation of treatment in at least two determinations more than 4 weeks apart
IU/mL
Decrease in histology activity index by at least 2 points and no worsening of fibrosis score compared to pre- treatment liver biopsy
Fulfill criteria of biochemical and virological response and loss of HBsAg
Time of Assessment During therapy
Persist throughout the course of treatment At the end of a defined course of therapy After discontinuation of therapy
6 months after discontinuation of therapy 12 months after discontinuation of therapy
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