Adefovir
Rapidly Suppresses HBV in HBeAg-negative Patients
Who Develop Resistance to Lamivudine
Progression of hepatitis B in patients with lamivudine
(Epivir-HBV)-resistant strains is slowed
down by adefovir dipivoxil/ ADV (Hepsera). Whether
the time point of ADV administration (genotypic vs. phenotypic
resistance) influences the outcome of
therapy is unknown.
In
the current study, Italian researchers compared the
outcome of ADV therapy in hepatitis
B e antigen (HBeAg)-negative chronic hepatitis B
patients with genotypic and phenotypic resistance
to lamivudine.
Results
Ten milligrams of ADV
was administered daily for 2 years to 46 HBeAg-negative
patients at the time of phenotypic resistance (group
A, >6 log(10) copies/mL of hepatitis B virus [HBV]
DNA and high alanine
aminotransferase [ALT] levels) and
28 patients at the time of genotypic resistance (group
B, 3-6 log(10) copies/mL of HBV-DNA and normal ALT).
HBV
DNA
was assessed every 2 months using Versant 3.0 assay,
and lamivudine resistance was confirmed via INNO-LiPA
assay in all patients.
By
month 3, HBV DNA tested negative in all patients from
group B compared with only 20 (46%) in group A (P
< .0001).
The
2-year rates of virological response were 100% in
the former patients and 78% in the latter ones (P
< .0001).
ALT
levels remained persistently normal in all group B
patients, whereas in group A patients, they normalized
at rates of 50% at month 6 (P < .0001), 72% at
month 12 (P < .01), and 93% at month 24.
None
of the patients developed ADV
resistance or ADV-related
side effects.
In
conclusion, the authors write, “To optimize antiviral
treatment in HBeAg-negative patients selecting resistant
strains to lamivudine, ADV should be added to lamivudine
as soon as genotypic resistance is detected.”
Department of Gastroenterology and Endocrinology, AM
and A Migliavacca Center for Liver Disease, IRCCS
Maggiore Hospital, Fondazione Policlinico, Mangiagalli
e Regina Elena, University of Milan, Italy.
12/16/05
Reference
P
Lampertico and others. Adefovir rapidly suppresses
hepatitis B in HBeAg-negative patients developing
genotypic resistance to lamivudine. Hepatology
42(6): 1414-1419. December 2005.
