Express Scripts and Medco Expect Mergers to Be Completed by Earlier Part of Q2

Under the terms of the previously announced Agreement and Plan of Merge by and among Express Scripts, Inc. ESRX, Medco Health Solutions, Inc. MHS, Aristotle Holding, Inc., a Delaware corporation and wholly owned subsidiary of Express Scripts, Aristotle Merger Sub, Inc., a Delaware corporation and wholly owned subsidiary of Parent, and Plato Merger Sub, Inc., a Delaware corporation and wholly owned subsidiary of Parent, following closing, each of Express Scripts and Medco will become an direct, wholly-owned subsidiaries of Parent. As a result of the transactions contemplated by the merger agreement, former Medco and Express Scripts stockholders will own stock in Parent, which, following the closing, is expected to be renamed “Express Scripts Holding Company” and to list its common stock on the NASDAQ. Express Scripts and Medco have previously announced that the parties expected that the mergers will be completed by the earlier part of the second quarter of 2012. Express Scripts now expects the parties may be in a position to close the transaction as early as the week of April 2, 2012, subject to satisfaction or waiver of the remaining closing conditions. There is no assurance that the closing conditions will be satisfied or that the proposed mergers will be consummated.