That particular issue is something I Find very interesting.
Why would you show all your cards and limit your options I a negotiation setting?
In My opinion there are only two potential reasons.
A) the collaboration was in some way in the way of a deal with AZ.
B) it was too time consuming/demanding for a small orgainzation as PCIB.
Since Pcib has expressed that their collaborations we solely conducted and financed by their partners I do not see option (B) As a viable option. Thus, it has to be Option (A).
If the case is simply due to ”we do not see this panning out in any way“, why not wait until negotiations with AZ has been finalized?
So this leads me to think that Pcib and AZ have had a Common understanding (probably) for some time now, about the groundwork of a potential deal. What they are now waiting for is What is to be added/included to set deal.