Fortress Biotech, Inc., a biopharmacompany focused on acquiring, developing and commercializing promising products and product candidates cost-effectively, and a company it founded, Caelum Biosciences, Inc., a biotechnology company developing treatments for rare and life-threatening diseases, closed AstraZeneca’s acquisition of Caelum for approximately $150 million.   The agreement also provides for additional potential payments to Caelum stockholders totaling up to $350 million, payable upon ...