gofish
"I believe that the current SOC for gen 1 patients who are hcv-neg at wk.4 and remain so is 24wks"
I didn't know that. roche presented promising svr data after 24 weeks of therapy at recent AASLD in gen-1 pts who had a rapid virologic response (rvr)(undetectable at 4 weeks), but this was unblinded. clearly those with rvr do better, and 48 weeks may confer no benefit over 24 weeks, but this is still a far cry from 10 weeks. i guess my point was we know gen-1 overall requires longer tx durations, and even tx for many weeks following a negative pcr (3 months) is associated with higher relapses than tx for even more weeks post-virologic response (6 months) in the general gen-1 population (not specifically those with rvr). now maybe vx-950 changes all that, and even 10 weeks is adequate. or maybe rvr on a protease inhibitor doesn't predict svr to same degree because of resistance? maybe optimal svr following rvr on a protease inhibitor requires longer treatment times because behavior of residual virus is more aggressive?
"my WAG is relying on the extended length of triple therapy , versus the 2 or 4 wks"
good point, and i considered this as well when making my guess. but it is not a certainty that longer treatment periods with a protease inhibitor necessarily do better..it could be that the initial reduction of virus is so acute, and resistance, if it occurs, emerges quickly that there is no benefit conferred with an extra 6 weeks (or longer) of vx-950 (personally i doubt this is the case after just 2-4 weeks of tx, but you never know)
also, the 2 relapses in the IIa data verex presented occurred while continuing to take peg-riba, and in the current subgroup analysis there will be no follow on soc therapy after vx-950 combination therapy is stopped, so it is possible relapses may be higher post-treatment because there is no consolidation phase
"what I've seen suggests that the bulk of patients become hcv-pos. in the first month , and virtually all by 3 months. I'm making the assumption that high-sensitivity testing (10 IU/ml) will capture virtually all relapsers by 3 months off-treatment"
i looked this up recently and from what i recall there you're absolutely right in that most relapses will occur within 3 months, but there were enough between 3-6 months to justify a definition of svr at 6 months. I too haven't seen much data specifically using ultrasensitive assays and maybe with these assays svr12 will equal svr24. but I have seen data that shows that end of tx negatives using highly sensitive assays can still relapse, so for sure "undetectable" by an ultrasensitive assay doesn't really mean there is NO residual virus.
"Even if your guess of 60% SVR turns out to be correct , it will still be a dramatic result considering the shorter tx"
definitely..and to expound on that, even if longer tx periods significantly increase svr, those who can't tolerate the toxicity of longer treatment periods will still have a respectable chance of svr wiht a short course of therapy, and so the population of patients with hep c who choose treatment over no treatment will surely expand
"BTW , if this bet was for real money I'd bet on your numbers , not mine"
BTW I'd bet on yours (i was just offering a contrarian view to your arguments ;)
PS: This IS for real money if you've got positions in the hep C marketplace!
AI
