I would agree the most optimistic expectations for arms E and F in the Vertex Zenith trial will likely eventually show SVR 24 somewhere between 79% seen in the current treatment paradigm of Incivek + SOC and the "quad" therapy results which I recall as exceeding 90%. The timing of the first interim data IMO will be announced most likely at the time for the fourth quarter earnings conference call on Feb. 2, just as Jeff Leiden officially assumes the duty of CEO. In his remarks on this data at JP Morgan's healthcare conference this week, he mentioned that EOT data on arms E and F would first be released with subsequent "SVR 4" data to be releaased when available lster this quarter.
Remember, it's been mentioned several times to date that no viral breakthrough has been reported on these arms of Zenith through 2011. With regard to comparing the perfect cure rates of Pharmasett's nuc + riba in GT 2 patients reported at AASLD last November, to this all oral Vertex regimen treating GT 1 patients... that's like comparing treating cure rates for the easiest to cure lymphoma with the most difficult to treat lymphoma. It's not a reasonable assumption to make that a treatment regimen for an easier to treat form of hep C will get the same high SVR 24 rates in the most difficult to treat sub populations with hep C including GT 1A and 1B, African Americans, HIV coinfected, post transplant etc. If the interim data to be announced in arms E and F of the Zenith trial exceeds expectaions, it will be first all 0ral regimen in GT 1 patients to have promise and that will likely be a huge catayst for Incivek and VX 222 to move into Phase 3 trials as the first all oral treatment for treatment naive GT 1 patients. I would not worry too much about the number of pills and consider more the improvved toleralbility of the regimen i.e. fewer drop outs due to less frequent or less severe incidence of rash etc., which may further enchance cure rates if most all patients can finish treatment. Q
The main reason for VRTX pps drop from its high (in addition to profit taking) has been all the publicity from VRUS's all oral followed by INHX's all oral.
VRUS's quad regimens produced around 91% SVR in easy to treat groups which included Geno 1 types but did not include a single African descent patient(hard to treat group). VRUS's hyped 100% results as we all know is NOT for Geno 1, so drawing any conclusions from that about Geno 1 is foolish. So even if we use their quad efficacy of 91%, the question then becomes what effect will removal of INF have on SVR. My WAG is that it may be at least 10 to 20% less effective. If so, why would any patient want to risk taking the oral regimens if it is not as effective as the regimens that include INF. Does INF have side effects? You bet. Will INF kill a person? I don't think so. There may be a few patients here and there whose side effects may be so bad that they rather die than continue taking INF. Only for those patients the all oral may be appropriate.