NEW YORK -- A judge must halt sales of a generic version of the blockbuster blood thinner Plavix or risk jeopardizing the drug industry's existing methods for research and development, a lawyer argued in federal court on Friday. Sanofi-Aventis, which invented Plavix, and Bristol-Myers Squibb Co., which markets the drug in the U.S., are seeking an injunction to block further sales of Canadian drug maker Apotex Inc.'s generic version of Plavix. .