Both Yervoy and BMS' anti-PD-1 compounds came from Medarex.
The PD1 drugs will be the biggest blockbusters to come to oncology, perhaps ever.
I think the only criticism one can lay on Medarex management right now is that they sold out for a terribly low price considering the value PD1 will have in the future (although, shareholders made out well back then, I would assume...just not as much as they could have had they not sold the company)