Idenix Pharmaceuticals (IDIX)

[gofishmarko]

I've been curious about the reasons for the slow uptake of Tyzeka , so I did a little web searching. I came across the recently updated (2007) AASLD Treatment Guidelines for HBV.

pdf at :

https://www.aasld.org/eweb/docs/chronichep_B.pdf

The bottom line is that Tyzeka is clearly relegated to the second tier of treatment options , for almost all patient cohorts. Adefovir , entecavir , and pegifn are listed as front-line , with various qualifications depending on whether patients are naive , lam-resistant , HIV-pos , etc.

Until IDIX can produce data that shows a good head-to-head comparison versus the currently-favored agents ( over several years , probably ) , it's hard for me to see how Tyzeka will ever capture a market share similar to those other drugs. I realize that the AASLD guidelines are not the last word , especially considering the global market , but they carry a lot of weight in the U.S. and probably the EU , as well.

Here's a couple of excerpts from the pdf ( See Table 11 for a summary of tx. recs ):

"Telbivudine is an L-nucleoside analogue with potent
antiviral activity against HBV. Clinical trials showed that
telbivudine is more potent than lamivudine in suppressing
HBV replication. However, telbivudine is associated
with a high rate of resistance and telbivudine-resistant
mutations are cross-resistant with lamivudine.
Therefore, telbivudine monotherapy has a limited role in
the treatment of hepatitis B."

"Patients who are not on HAART and are not
anticipated to require HAART in the near future
should be treated with an antiviral therapy that does
not target HIV, such as pegIFN-
, adefovir, or entecavir.
Caution should be exercised if entecavir is used
in this setting. Although telbivudine does not target
HIV, it should not be used in this circumstance."

"In choosing which antiviral agent to use as the firstline
therapy, consideration should be given to the
safety and efficacy of the treatment, risks of drug resistance,
costs of the treatment (medication, monitoring
tests, and clinic visits), as well as patient and provider
preferences, and for women—when and whether they plan to start a family. ...

...In view of the high rate of drug resistance during long-term treatment, lamivudine and telbivudine are not preferred except where only a short course of treatment is planned."

etc.