Please notice Vertex' plan to expand New Zealand trial to include GT 3 infections following the initial trial for GT 1.
NEJM also reports results from Sofo + Riba treatment for HCV 2 and 3 infected individuals. But we know already from meeting abstracts that the following is true.
Treatment-naive patients in the FISSION trial of sofosbuvir plus ribavirin for 12 wks achieved SVR12 rates of 97% if they were infected with HCV genotype 2, but only 56% if infected with HCV genotype 3.
The FUSION trial of sofosbuvir plus ribavirin for 12 or 16 wks in treatment-experienced patients also reported that 94% of HCV genotype 2–infected patients treated for 16 wks, NOT 12 wks, achieved SVR12 vs only 62% of those infected with genotype 3. pIFN+Riba can do better than Sofo+Riba can -- 69% for GT 3.
Clearly, treatment for GT 3 infection has a room to improve today.
Global prevalence of GT 3 is less than GT 1, but it is a significant fraction of the total Hep C patients in Europe. For example, in Germany 26% of Hep C individuals under age 40 years was infected with GT 3 (10 years old data).
Third, is there any data on Sofo/ledipasvir with GT2 and GT3? If Vx-135 combo with PI is also effective, there will be two players in the game. That being said, I believe most of the market is outside of the US where costs will need to come down.
Harvey, Gilead's data treating GT1 and GT2 infections has been very strong whether they involve Sofo + Riba or Sofo + Ledi. For Sofo+Ledi+/-Riba, their latest data in HCV are their LONESTAR trial interim results, which gave 95-100% for GT1 infection. This is a high bar for VX-135 to cross. On the back of these impressive results, they started ION-3 for GT1 naive earlier this year.
Another trial which gave April 2013 as the starting date treats GT 1, 2, and 3. It is very curious to see that they are not treating only with Sofo+Ledi, but also with Riba or GS-9669 (their VX-222!!!). Apparently, they felt they needed three-drug combo.
A third trial which started June this year treats GT3 with Sofo+Riba only, but for a duration of 16 wks or for 24 wks.
There was no press release for results of Sofo+Ledi on GT3.