Replies to post #137347 on Biotech Values

[oc631]

apparently we now learned that many nulls are in fact resistant to ribavirin - or else how do you explain the difference (even in these small numbers) between the treatment naive and null populations in the 7977 study

The poor results from GS-7977 monotherapy in GT2/GT3 patients proved ribavirin will be a essential part of oral therapy using the pyrimidine nuke. The data released last week appears to suggest what was lacking in interferon-based therapy for nulls is what's lacking now. Activity of the ribavirin component.

[genisi]

apparently we now learned that many nulls are in fact resistant to ribavirin - or else how do you explain the difference (even in these small numbers) between the treatment naive and null populations in the 7977 study

There are several variables we should consider when looking at 7997 data: GT1 vs GT2/3 and null vs naïve.
Riba could be too weak in GT1 and potent enough in GT2/3 or perhaps nulls are resistant to Riba as you suggested. Either way, replacing Riba with a more potent DAA should help. The other possibility is that an agent with different MoA (not a DAA but like IFN) is needed for viral clearance and cure. I'm leaning toward the first.