my concern would stem from the fact ABBV could argue that since there are 4 drugs ENTA is entitled to 25% - regardless of whether one of the components is generic, unless this is spelled out specifically in the agreement i would also think the ABT-450 component should garner more than a third of the contribution to efficacy given it really is the backbone of the cocktail and they've played around with the other DAA components (in fact 450+1 other DAA did fairly well). It's comparable to (but not quite) like saying sofosbuvir contributes more than 50% to GILD's sofo/led combo - which i don't think anyone would dispute