Eusa Pharma, Inc. has entered into a definitive agreement to acquire all the outstanding shares of Cytogen Corp. for $22.6 million cash. Cytogen has three oncology and pain control products on the U.S. market, a specialized oncology sales force, and an established commercial infrastructure.       “The acquisition of Cytogen is of great strategic importance for Eusa as it completes the building of our transatlantic commercialization infrastructure, as well as fitting perfectly with our f...