Reuters Health Information (2011-03-18): Entecavir shows promise as first-line drug for chronic HBV
Entecavir shows promise as first-line drug for chronic HBV
Last Updated: 2011-03-18 19:14:26 -0400 (Reuters Health)
NEW YORK (Reuters Health) - A small group of patients on long term entecavir (Baraclude) for chronic hepatitis B have had lasting viral suppression and regression of advanced cirrhosis, a new report indicates.
The ten patients had taken the oral antiviral agent for at least three years (on average, six years). All of them started on it as participants in various trials of entecavir for hepatitis B virus (HBV) infection.
Entecavir and tenofovir should be the two first-line oral drugs for HBV, according to researcher Dr. Samuel Lee from the University of Calgary, Alberta, Canada.
"They are the most potent viral suppressors and have been shown to be superior to lamivudine which is still used commonly worldwide due to its comparatively low cost," Dr. Lee told Reuters Health by email.
Long term use of lamivudine is associated with high levels of drug resistance, Dr. Lee and his colleagues point out in the March issue of Clinical Gastroenterology and Hepatology.
For the current report, the authors analyzed hepatitis B virus DNA levels and biopsy samples taken at baseline and after 267 to 297 weeks of treatment. Declines of at least two points in the Knodell necroinflammatory score and one point in the Ishak fibrosis score were considered significant improvements.
At baseline, the mean HBV DNA load was 8.7 log10 copies/mL and the median Ishak and Knodell scores were 4.6 and 10.3 respectively, suggestive of advanced cirrhosis or fibrosis.
But on the final biopsy, every patient had at least a one-point decline in the Ishak score, with longer treatment linked to a greater magnitude of improvement.
Also, the authors found mean declines from baseline of 2.2 in Ishak fibrosis and 7.6 in Knodell necroinflammatory scores. All four patients with cirrhosis at baseline had reductions in Ishak score to 4 or less (indicating their scarring or fibrosis was no longer "extensive").
HBV DNA had become undetectable (i.e., < 300 copies/mL) after 48 weeks of treatment and remained so thereafter in all of the patients. The authors note that "rapid and sustained virologic suppression to undetectable levels is associated with a lower risk of developing antiviral resistance."
"There is no 'cure' for hepatitis B. The oral suppressive drugs such as entecavir generally just suppress viral replication as long as the patient remains on the drug," Dr. Lee said.
Seven patients were hepatitis B e antigen (HBeAg) positive. "In some cases, particularly HBeAg-positive patients, the drugs can convert a replicative state to a relative nonreplicative state and treatment can be stopped," Dr. Lee added.
All of the patients in the study were men. Four were of Asian descent.
The study was sponsored by Bristol-Myers Squibb, which markets entecavir as Baraclude; the lead author is on its scientific advisory board.
Clin Gastroenterol Hepatol 2011;9:274-276.