Hepatitis B drug achieves rapid virus suppression
Hepatitis B: reducing virus levels improves outcome |
Entecavir maintains greater viral load suppression and lower levels of resistance in hepatitis B patients compared with lamivudine, suggest data that were presented at the annual meeting of the European
Association for the Study of the Liver in Vienna last month.
One drawback of lamivudine is that, after four years of treatment,
around 60 per cent of patients develop resistance, resulting in relapse
and
disease progression. Entecavir has been developed so that it is less
likely to result in resistance — it inhibits three steps of the
virus’s DNA polymerase enzyme, compared with lamivudine’s
two.
In a phase III study, 638 nucleoside-naive, chronic hepatitis B e-antigen-negative
patients were randomised to receive either entecavir 0.5mg once daily
or lamivudine 100mg once daily for a minimum of 52 weeks. At week 52
patients were categorised into one of three groups — non-responders,
responders for both virus levels and liver function and responders with
persistent enzyme elevation. The last group went on to receive blinded
treatment until week 96.
Results show 94 per cent of patients in the entecavir treatment group
achieved virus suppression to undetectable levels compared with 77 per
cent of patients given lamivudine (P<0.001). Additionally, the proportion
of patients achieving alanine aminotransferase enzyme level normalisation
was 89 per cent for patients treated with entecavir compared with 84
per cent of patients treated with lamivudine (P=0.05).
The safety profile of the two treatments was comparable, with no evidence
for the emergence of viral resistance seen at 96 weeks treatment with
entecavir.
Howard Thomas, head of the liver unit at St Mary’s Hospital, London,
commented: “The importance of the study is that entecavir is bringing
the virus under control more rapidly than lamivudine, giving less chance
for the virus to develop resistance to the drug. Studies have shown that
patients with high levels of viral replication have a higher chance of
dying from liver cancer and cirrhosis than those with low levels. It
has also been shown with lamivudine that if you reduce levels of the
virus, this has a positive impact on a patient’s long-term outcome.”
Last month, the European Medicines Agency’s Committee for Medicinal
Products for Human Use adopted a positive opinion for entecavir, indicating
that approval is likely to be granted later this year (PDF 120K). |
The
Pharmaceutical Journal
Acrobat
Reader