In my mind's eye, I've been expecting a gain of maybe $1 a share if the SGN33 trial results in favorable news, and a quick drop of about $2, maybe a little more, if the SGN33 trial results in unfavorable news, largely as a result of pure market reflex and the company's proven inability to properly manage such news with relevant context.
That said, I'd expect the stock to rebound off any such setback pretty quickly, given that those who really know what's going on at SGEN will be looking ahead to the SGN35 trial results, which one might expect to deliver very good news.
If the results of the SGN-33 are strongly positive as regards to one year survival ( say, perhaps, 40-50% on SGN-33 versus a historical 25% average for low dose chemo ) and the study looks like it could, by itself, serve as the basis for a successful FDA registration submission then SGEN goes up to between 20 to 35 right away. Much lesser shades of success and any questions regarding the present study being capable by itself of supporting a registration with the FDA and the rise is between 1-5 points depending on the percieved strength and quality of the study data ( which could await presentation at a medical conference for all the data subtleties to play out ).
If SGN-33 clearly fails, a 1 to 2 point dip with recovery over a relatively short time.
Above is just speculation, conjecture, musing....I think you get the point.