Shares of drugmaker Medicines Co. (MDCO) plunged Thu. after an FDA panel voted against approving the company's anti-platelet drug inhibitor. On Wed., trading of the firm's stock was halted after the panel voted 7-2 against approving the drug, which would be used to prevent clotting in patients undergoing cardiac stent procedures. The panel criticized the design of one of the trials, and said the bleeding rate compared unfavorably with current drugs. Shares plunged 11.5% to 29.28.