Not going to happen.
With all that is going on and going right (i.e. establish ADCETRIS as a franchise drug as one that is already approved so successful trial completion will boost sales immediately) the market cap will grow metheorically in the next 3 to 5 years, there are many clear indications that Mr Segal is totally focused and has access to the financial firepower for getting it done without additional muscle. A buyout now would be both a distraction and not in the best interest of SGEN investors.
If even only half of current trials/partnerships work out, SGEN revenues can easily exceed $ 4 to 5 Billion in 3 to 5 years.
No acquiring company CEO is going to propose paying the preset value of that revenue stream today and Mr Segal appears not to be inclined to sell at a discount.
You just posted exactly why they will be bought out!! They are in the sweet spot for a buyout, just prior to label expansion and further validation of pipeline. I don't remeber a poison pill clause but could be wrong. I'm just saying they are way too attractive to BP expecially any that have an antibody library!