TreatmentUpdate 72, Vol. 8, No. 8; October 1996
Background
Gilead Sciences which makes the anti-CMV drug cidofovir is also
developing a treatment called adefovir (Bis-POM PMEA) for
hepatitis B infection. Although most people quickly recover
from HBV (hepatitis B virus) infection, a few develop
continuous (chronic), low-level HBV infection in the liver.
Over time HBV infects more liver cells and the damage slowly
spreads through the entire organ. Eventually the liver damage
is so severe that some people die and others get liver cancer.
Doctors rely on interferon alpha to treat HBV infection but
this drug is not always useful.
Study details
Doctors enrolled 20 subjects with chronic HBV infection into
this study. Sixty-five percent of them also had HIV infection.
Doctors randomly selected 15 subjects and gave each, one tablet
of adefovir (125 mg) daily and 5 other subjects fake adefovir,
both for 1 month.
Results
Levels of HBV fell by 97% compared to their pre-study level in
subjects receiving adefovir. Subjects receiving fake adefovir
had their level of HBV rise by 7% during the study. This
difference in HBV levels between the two groups of subjects was
statistically significant. This means that the changes in HBV
levels were likely due to the use of adefovir and not a chance
event.
Toxicity
Two subjects using adefovir had nausea while three had higher
than normal levels of liver enzymes in their blood ; which
indicated mild liver damage. HBV infection can also cause
increases in liver enzyme levels. In other studies, nearly 200
HBV-infected people have used adefovir 125 mg/day for up to 14
months "without any sign of toxicity." In the US, adefovir is
also being tested with AZT and related drugs as well as
protease inhibitors as a treatment for HIV infection.
REFERENCES:
1. Gilson RI, Chopra K, Murray-Lyon I, et al . Adefovir
dipivoxil (Bis-POM PMEA) treatment for chronic hepatitis B
infection; a placebo-controlled phase I/II study. Abstract
LB01.
2. Anonymous. Gilead Sciences announces statistically
significant antiviral activity against hepatitis B virus. Press
release 16 September, 1996.