By
Liz Highleyman
Gloria
Woo from the University of Toronto and colleagues aimed to
determine which approved antiviral drugs were the most effective
therapies for chronic hepatitis B, focusing on relative efficacy
during the first year of treatment.
The researchers searched medical publication databases for
English-language reports of randomized controlled trials looking
at the first 12 months of therapy in hepatitis B "e"
antigen (HBeAg) positive or HBeAg negative chronic hepatitis
B patients published before October 31, 2009.
The analysis included trials evaluating the oral agents lamivudine
(Epivir-HBV), adefovir (Hepsera),
telbivudine (Tyzeka), entecavir,
and tenofovir, as well as injected
pegylated interferon (Pegasys
or PegIntron) -- both as monotherapy and in combination regimens
-- for treatment-naive individuals.
Results
 |
In
studies of HBeAg positive patients, tenofovir was most
effective at producing the following outcomes: |
| |
 |
Undetectable
HBV DNA viral load (predicted probability 88%); |
|
Alanine
aminotransferase (ALT) normalization (66%); |
|
HBeAg
seroconversion (20%); |
|
Hepatitis
B surface antigen (HBsAg) loss (5%). |
|
|
Tenofovir
ranked third for histological improvement of the liver,
e.g., regression of fibrosis (53%). |
|
Entecavir
was most effective at improving liver histology (56%),
second at producing undetectable HBV DNA (61%) and ALT
normalization (70%), and third for HBsAg loss (1%). |
|
In
studies of HBeAg negative patients, tenofovir was most
effective at producing undetectable HBV DNA (94%) and
improving liver histology (65%), and ranked second for
ALT normalization (73%). |
Based
on these findings, the study authors concluded, "In the
first year of treatment for chronic hepatitis B, tenofovir
and entecavir are the most potent oral antiviral agents for
HBeAg positive patients; tenofovir is most effective for HBeAg-negative
patients."
Investigator affiliations: Toronto Health Economics and
Technology Assessment Collaborative, University of Toronto,
Toronto, Ontario, Canada; Departments of Medicine and Health
Policy, Management and Evaluation, and Faculty of Pharmacy,
University of Toronto, Toronto, Ontario, Canada; Hospital
for Sick Children Research Institute, Toronto, Ontario, Canada;
University Health Network, Toronto General Research Institute
and Clinical Studies Resource Centre Toronto Western Research
Institute, Toronto, Ontario, Canada.
8/24/10
Reference
G Woo, G Tomlinson, Y Nishikawa, and others. Tenofovir and
Entecavir Are the Most Effective Antiviral Agents for Chronic
Hepatitis B: A Systematic Review and Bayesian Meta-Analyses.
Gastroenterology (Abstract).
June 20, 2010 (Epub ahead of print).
