The problem is that there is nobody else but abbvie. My thesis is that it is too hard for a 3rd party(beyond abbvie) to come in and untangle the legalities.
So imo if abbvie does not bid, there is probably no one else.
Considering what MRK paid for IDIX's nukes as well as what seems like a real interest by NVS in advancing ENTAs compound, I would like to think $1.5b would be the minimum someone would have to pay.
Why $1.5b? Why not 0.5B, $3B or $5B?
Remember that no Big Pharma will touch a product with a potential sale below $300M.