If GS-7977/ribavrin fails in treatment-naive genotype 1 hepatitis C and the Alios nucs (2158 and 2200) have good phase 1 data, then Vertex will be even with Gilead in the race to develop the first oral combination regimen for genotype 1 hepatitis C. Both companies will plan multiple phase 2 studies combining their nucs with other protease inhibitors, polymerase inhibitors and ribavirin. The Pharmassett acquisition will lose most of it's value in this scenario.
For what Gilead paid for PS-7977, they could have bought all of VRTX and gotten the VX-950 plus everything else in the VRTX pipleline. Now they are trying to justify the purchase by trying the all-pill therapy for only 12 weeks, and the results are predictably poor with the Genotype 1s. It is actually worse than this because the poor folks in the clinical trial who relapsed now probably have a mutant version of the virus and are in deep trouble.
I am betting Gilead will have less than a 60% SVR for GS-7977/ribavirin in genotype 1 naive hepatitis C patients. Why? First, complete failure of GS-7977/ribavirin in genotype 1 null hepatitis C patients. Second, remember that the great results reported for GS-7977 last year were all in easy to treat genotype 2 and 3 hepatitis C. Third, Pharmassett and its 7977 were so massively overhyped that the whole thing is starting to look like a huge deception designed to enrich a lot folks on Wall Street who have already cashed out.
The GS-7977/ribavirin oral regimen has failed miserably for the treatment of those genotype 1 hepatitis C patients that had previously failed treatment with interferon/ribavirin ("null responders"). The failure rate appears to be close to 100% and this was unexpected. The great results seen with GS-7977 in past studies were achieved when it was paired with both ribavirin and interferon. Apparently, GS-7977 is heavily dependent upon interferon to eradicate the hep C virus. It will be interesting to see how GS-7977/ribavirin performs in treatment-naive genotype 1 hep C patients. The odds of failure in this treatment-naive genotype 1 hep C went way up when it was announced that GS-7977 failed in null responders.
Actually, Vertex will be the clear leader if GS-7977/ribavirin fails in treatment-naive GT-1 hep C because the Incivek/VX-222/ribavirin regimen would then be the best oral combination in clinical trials for these patients.