You are making the assumption that management is actively pursuing other bids and that the board would even give them consideration if one came along. Even if there were other potential suitors, I doubt management or the board would do anything to throw this deal considering they are employees on both sides of the table. That is just all part of the show in my opinion.
So to answer your question, there my be other interested parties but I doubt we will ever know (just like we were never told about discussions with Teva) and unfortunately the board has a lot of leeway in determining what is the "best" and price is not always the winner in the decision making process - especially when you have conflicted management and a conflicted board. The whole process is a big joke. In the end they will do whatever is best for them period.