The Wall Street Journal reports this morning that “Health insurer Cigna Corp. plans to buy [prescription benefit manager] Express Scripts Holding Co. ESRX -1.56% in a cash-and-stock deal worth $52 billion, excluding debt, that the companies say will expand their health care offerings and help them control costs.”  The companies expect that the deal, which is subject to shareholder and regulatory approvals, will close this year.  Both companies are active vendors in the FEHBP space.