Shares of Alexion Pharmaceuticals are up 6% to $114.00 in pre-market trading after the company earlier disclosed that it had “recently engaged in good faith with Elliott Advisors Limited, an affiliate of Elliott Management.” The activist investing firm recommended that the drugmaker “immediately launch a proactive sale process,” but Alexion said its board of directors had “unanimously decided that conducting a proactive sale process would not be in the best interest of shareholders and the patients we serve at this time.”