FDA Safety Changes: HEPSERA
August 28, 2008 — The US Food and Drug Administration (FDA) has approved
safety labeling revisions to advise of
therapeutic recommendations that may reduce the risk for resistance to
adefovir dipivoxil therapy.
Recommendations for Adefovir Dipivoxil (Hepsera) Usage May Reduce Risk for
Resistance
On May 27, the FDA approved safety labeling revisions for adefovir dipivoxil
(Hepsera; Gilead Sciences, Inc) to advise of the potential for clinical
resistance.
Resistance to adefovir can result in viral load rebound and exacerbation of
hepatitis B virus infection (HBV), potentially leading to liver decompensation
and fatal outcome in patients with diminished hepatic function.
To decrease the risk for resistance in patients with lamivudine-resistant HBV,
adefovir should be administered in combination with lamivudine rather than as
monotherapy. For those receiving adefovir alone, treatment modifications
should be considered if serum HBV DNA levels remain above 1000 copies/mL with
continued therapy.
The latter recommendation is based on long-term (144-week) data from an
adefovir clinical trial (n = 124), in which HBV DNA levels greater than 1000
copies/mL at week 48 were associated with an increased risk for the
development of resistance.
Adefovir is indicated for the treatment of HBV in patients aged 12 years and
older who have evidence of active viral replication and either persistent
elevations in serum aminotransferases or histologically active disease.