ENTA is presumably still modeling the up-front development costs associated with opting in. Inasmuch as the ABT-493/ABT-530 program is just starting phase-2b, those costs could be considerable, particularly if phase-3 trials will require an approved all-oral regimen as a comparator.
If I had to make a bet, I would say there’s a 45% chance that ENTA opts in. Please note that this decision affects the US market only; in the rest of the world, ENTA will receive milestone payments and royalties from ABBV regardless of the arrangement in the US market (#msg-104670740).
“The efficient-market hypothesis may be the foremost piece of B.S. ever promulgated in any area of human knowledge!”