Replies to post #75541 on Biotech Values

[dewophile]

"I do think interferon lambda has a bigger chance in HBV than HCV because there won't be a direct anti viral cocktail any time soon"

well interferon now isn't used much in HBV due to limited efficacy and tolerability. unless lambda can show improved efficacy compared to alpha interferons i doubt a better tolerability profile alone will enable it to garner more market share. as for HCV I won't rehash the debate on this board re the role of interferon - you know where i stand. i find it interesting though that a few years ago most of the hullabaloo was about getting rid of ribavirin. that failed (so far). now the focus has turned on eliminating interferon, but i think people forget interferon also plays a role in imunomodulation and relapse, not just in driving down viral load, and interestingly this HBV thread reminds us of that fact (that while efficacy in HBV is limited for interferon, only interferon - not direct agents, even after prolonged levels of undetectable HBV often - can achieve a sustained response in HBV)
bottom line is for HCV we have no idea at this point. this is the study that will have to be done:

1. direct agent combos for who knows how long (24 weeks?) followed by placebo
2. combo including rib or followed by rib alone
3. combo including interferon or followed by interferon alone
4. combo followed by rib and interferon

my bet is that #1 fails to achieve acceptable SVR compared to 2-4. i know DD thinks otherwise (although side note - his own company's CEO JP somadossi thinks otherwise)
i also think there will always be some difficult to treat patients that will gain worthwhile improvement in SVR from #4 - could be a tiny fraction, could be a very meaningful fraction, could be ALL comers - we jsut don't knwo yet

i guess i didn't let the topic rest ;)

[iwfal]

The trial was to look at the efficacy of combining lamivudine and interferon. The combo is effective in increasing % patients with undetactable HBV DNA, but the seroconversion rate is not significantly different from interferon therapy alone because many patients relapse.

I am assuming that you are referring to the study published in NEJM?

If so I'd like to point out something pertinent to this thread: it is true that the combo had a higher percentage of patients with with very low(not sure it was detection limit) viral load (<400 copies/ml) at the end of treatment, but did NOT have a higher rate of viral response compared to ifn alone after 24 weeks of followup. (i.e. the extra benefit of combo with Lam was completely washed out by 24 weeks after last treatment)

PS I generally agree that Hep B seems to be further behind than Hep C and tougher to treat - so it is potentially a substantial market for a better ifn.

PPS I would really like to understand why HVB chose to go with seroconversion as their primary metric and HCV chose to go with viral load.