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Press Release from Roche
Pegasys (pegylated interferon alfa-2a) Treatment for Hepatitis B
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"Treatment with Pegasys (peginterferon alfa-2a) Doubles Effectiveness Rate of
Standard Interferon for Chronic HBV Infection"
Study results presented today at the 11th International Symposium on Viral
Hepatitis and Liver Disease in Sydney Australia demonstrate that Pegasys more
than doubled the efficacy of conventional interferon in the treatment of
chronic hepatitis B (CHB).
Pegasys given for six months at the same 180 microgram dose as in the
treatment for hepatitis C, showed a combined end point of HBeAg loss, HBV DNA
below 500,000 copies/ml and normalisation of ALT, of 28% compared to 12% for
conventional interferon (Roferon).
The Phase II study assessed the efficacy of Pegasys in patients with
difficult-to-treat HBeAg-positive CHB, which was defined as high
pre-treatment HBV DNA (high levels of replicating virus in the patient's
liver) and low pre-treatment ALT (indicating a weak natural response from
the patients immune system to HBV). These factors are considered predictors
of a poor response to HBV therapy. As in hepatitis C, where genotype 1 is
considered difficult to treat, there is also evidence that those infected by
the HBV genotype C virus respond less well to treatment.
"Until now, there was only a slim chance that these hepatitis B patients
could be cured of their disease," said Professor Graham Cooksley, the lead
investigator of the study and Senior Principal Research Fellow, Clinical
Research Centre, Royal Brisbane Hospital, Australia. "These [Pegasys]
monotherapy results are extremely positive and demonstrate the same kind of
efficacy in hepatitis B as we saw with genotype 1 patients in hepatitis C.
Pegasys works very well in those with the most treatment-resistant disease."
PEGASYS fared better than conventional interferon in every efficacy parameter
measured. The efficacy parameters were:
- HBeAg loss (loss of viral protein indicates that viral replication has
stopped)
- HBV DNA below 500, 000 copies/ml (a level that indicates the virus is
being effectively controlled)
- normalisation of ALT (normal ALT enzyme level reflects normal function of
the liver)
When all of the response criteria noted above are met, this is described as a
"combined response."
Results in difficult-to-treat HBV Disease
- In patients with low pre-treatment ALT ( 0- 2 x upper limit of normal),
the combined response was achieved in 27% of patients treated with Pegasys
compared to 11% of patients treated with conventional interferon.
- In patients with high pre-treatment HBV DNA ( > log 8.5 HBV DNA), the
combined response was achieved in 20% of patients on Pegasys compared to 14%
of patients treated with conventional interferon.
- In patients with HBV genotype C, the combined response was achieved by
21% of Pegasys patients compared to 6% of interferon patients.
The 194 patients in the study were treated with either conventional
interferon three times weekly or Pegasys (at 90 mcg, 180 mcg or 270 mcg) once
weekly for a 24-week-period, and were then observed with no further treatment
over the subsequent 24 weeks.
In addition to this research effort, there are two phase III studies
approaching completion.These studies explore the benefit of a longer
duration of treatment (48 weeks) where it is postulated that even higher
response rates may be achieved based on data with conventional interferon.
These studies, which use the same 180 mcg dose, will also explore the
efficacy of combining of Pegasys with lamivudine, a nucleoside analogue.
New Hope for HBV Sufferers
Currently, lamivudine, adefovir dipovoxil and conventional interferon alfa
are the sole agents approved for the treatment of hepatitis B.However,
these agents have clear limitations in terms of overall efficacy and about 20
per cent of patients treated with lamivudine develop resistance to the drug
within one year of therapy.Importantly, the hepatitis B virus is unlikely
to develop resistance to Pegasys. In addition, the majority of patients
treated with lamivudine are required to continue therapy indefinitely.
About Hepatitis B
Hepatitis B is a blood-born virus that attacks the liver and is the most
common serious liver infection in the world. The Hepatitis B virus is highly
contagious and is relatively easy to transmit from one infected individual to
another. It is 100 times more infectious than the HIV virus.
Despite a highly effective vaccine, More than two billion people have been
infected by HBV and 350 million people have chronic infection, which can be
easily transmitted by blood-to-blood contact, during birth, sex, and by
sharing needles.For those chronically infected with HBV, treatment is the
only option.Hepatitis B is the ninth leading cause of death in the world;
left unchecked, it can cause liver cancer and death.
About Pegasys
Pegasys, a new generation hepatitis C therapy that is different by design,
provides significant benefit over conventional interferon therapy in patients
infected with HCV of all genotypes. The benefits of Pegasys are derived from
its new generation large 40 kilodalton branched-chain polyethylene glycol
(PEG) construction, which allows for constant viral suppression.
Pegasys also distributes more readily to the liver (the primary site of
infection) than conventional interferon. Pegasys is the only pegylated
interferon available as a ready-to-administer solution. Each weekly
subcutaneous injection contains 180 mcg of pegylated interferon alfa-2a which
is the recommended dose for all patients, regardless of body weight.
Pegasys has been approved for the treatment of chronic hepatitis C in more
than 70 countries, including the European Union and the United States.The
most recent approvals for Pegasys have occurred in China and New Zealand.
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