The judge overseeing a private antitrust lawsuit seeking to block Express Scripts Inc. (ESRX)’s acquisition of Medco Health Solutions Inc. (MHS) set a hearing for April 10 on a request for an injunction to undo the deal. U.S. District Judge Cathy Bissoon in Pittsburgh today scheduled the hearing after a telephone conference with lawyers for the company and the trade groups suing to prevent the deal, which was approved yesterday by the Federal Trade Commission. She ordered Express Scripts to respond by April 6.