Replies to post #30258 on Biotech Values

[DewDiligence]

gofishmarko et al re VRTX VX-950:

Would anyone like to handicap the three cases in message #30264? Don’t be shy!

[gofishmarko]

RE: Handicapping VRTX

I'm assuming the listed outcomes could also refer to the triple therapy results , i.e. VX950 + ifn + riba , so with that qualification , here's my guess on the probabilities for the three outcomes :

1. If the SVR rate after 3 months of 950+ifn is <65%.....~10%.

2. If the SVR rate after 3 months of 950+ifn is >=85%....~60%.

3. If the SVR rate after 3 months of 950+ifn is >=65% and <85%....~30%.

Another way to say this is that I would expect > 90% probability that one of the 3-month regimens will result in >65% SVR , based on the results of the earlier , small studies. This assumes that the predictive power of RVR is still valid in VX950-containing regimens , of course.

[DewDiligence]

VRTX – By Josh Boger’s own admission, today’s VX-950 data will not be sufficient to leave him “delighted.” Boger had hoped that VX-950 would show an SVR rate (PCR-negativity 24 weeks following the completion of 12 weeks of therapy) of 85% or more (#msg-11635070). However, with PCR-negativity of 88% after 12 weeks, it's almost mathematically impossible to hit an SVR rate of 85%.

VX-950 is still a very good drug, but it's not heaven sent. VRTX will have to conduct full-fledged phase-3 trials—including some arms with 24 weeks rather than 12 weeks of VX-950—in order to submit a credible NDA.