several phase II sofosbuvir trials are also ongoing including a trial in patients with chronic renal insufficiency and trials investigating various regimens of sofosbuvir plus GS-5816 with or without ribavirin. in addition, an expanded access programme has been initiated for patients with aggressive, post-transplant,recurrent HCV infection for whom there are no other treatment options patient can receive sofosbuvir plus ribavirin with or without peginterferon-