With two new agents for HCV on the verge of approval, the question becomes which genotype 1 patients will get Gilead Sciences Inc.'s sofosbuvir, Johnson & Johnson's simeprevir - or both together - and which will be "warehoused" to wait for an all-oral, IFN-free solution.

It seems clear sofosbuvir is likely to become the backbone of the first interferon-free regimen in HCV, but only where it was tested in genotypes 2 and 3. In genotype 1 - which is most common in the U.S., Europe and Japan - the options are less straightforward.