You think SLXP gave so much to PGNX? It's a good deal in current economic condition but not exceptional. The deal is almost identical to original Wyeth deal with PGNX in upfront cash and milestone. Consider how much Wyeth had spent in getting to this point, SLXP got a great deal rather than paid so much in my opinion.
One of the big points for me is that SLXP is nowhere near the size or in the financial shape of a PFE/Wyeth. PFE/Wyeth can easily afford to shell out $60M up-front, in addition to all of the other potential milestones, and agree to fund all future costs. SLXP is nowhere near that size so such a financial commitment is much more material to a company like SLXP than it would be to PFE/Wyeth. That leads me to infer that SLXP really likes the opportunity they see in Relistor and believes they can succeed where PFE/Wyeth did not.