NEW YORK (Reuters Health) – During the first year of treatment for chronic hepatitis B, tenofovir and entecavir are the most effective antiviral agents available, according to the results of a systematic review and meta-analysis.

Writing in Gastroenterology published online June 20, Dr. Murray Krahn and colleagues explain that the more potent the agent initially used to treat chronic hepatitis B, the less likely is the development of cross-drug resistance with long-term therapy.

The researchers therefore reviewed “all published randomized controlled trials (RCTs) of drugs used to treat chronic hepatitis B as monotherapies or combination therapies to estimate their relative on treatment efficacies at the end of 1 year of treatment and to rank the treatments according to success rates for each outcome.”

The analysis included 20 trials looking at lamivudine, pegylated interferon, adefovir, entecavir, telbivudine, and tenofovir, as monotherapies and combination therapies, in treatment-naive individuals.

For HBeAg-positive patients, tenofovir was most effective for inducing undetectable viral DNA levels (predicted probability = 88%), entecavir ranked second (61%). On the other hand, entecavir was better than tenofovir in improving liver histology (56% vs. 53%).

In HbeAg-negative patients, tenofovir ranked first on both these measures: inducing undetectable HBV DNA (94%) and histologic improvement of the liver (65%).

Dr. Krahn and associates note that traditional meta-analytic techniques compare only two interventions at a time. The researchers used Bayesian mixed treatment comparisons to provide, “for the first time, the probability of an outcome at the end of one year of treatment as well as a rank for all treatments.”

That said, they point out that antiviral treatment of chronic hepatitis B frequently continues for much longer than 1 year, sometimes for a lifetime. Hence, the current results “are not sufficient to definitively resolve the question of optimal treatment choice.”

Reference:

Tenofovir and Entecavir are Most Effective Antiviral Agents for Chronic Hepatitis B; A Systematic Review and Bayesian Meta-Analyses

Gastroenterology 2010.