Celgene Corp. has agreed to acquire Pharmion Corp. for $72 a share in a cash-and-stock deal worth $2.9 billion. Celgene said this deal will give boost to its strategy in the hematology and oncology field and brings together three medical therapies — Revlimid, Thalomid and Vidaza — that are expected to accelerate revenue and earnings growth over the next five years.