Biotech Values

[dewophile]

What's the rationale for not using a response-guided protocol?

response-guided therapy as you know is aimed at shortening tx duration. i don't think vrtx thinks anyone can do with less than 12 weeks therapy (note very few pts were undetectable at 2 weeks, and some of those had rebound so it's a useless datapoint really)
i'm sure they will refine the study protocols when more data is in, but it might be something along the lines of 12 weeks for 1b, and either longer for 1a or response-guided for 1z - although note that the hardest component of tx is interferon and these are interferon-free regimens so the premium on shortening tx duration is also less

PS: ribavirin is proving hard to do without, but it also has a pretty bad SE profile. i think there is room for further improvement for all orals if someone can fine a ribavirin-free regimen