There is an SEC on Edgar about chancelor owning about 8% of celg. Maybe they are selling at these levels, and still profitable for them. Maybe they are PO'd that celg won't need their money. In any case if any of you understand the SEC mumbo jumbo, please post a message explaining it & if that could be causing the shakiness on the stock.
I doubt that the FDA can or would change their minds at this stage. They are the ones who pushed for thalidomide in the first place.