Shares of U.S. drug suppliers rose on Monday after a report that Amazon.com Inc had dropped plans to sell drugs to hospitals, in a boost to a pharmaceutical supply chain rattled by the looming threat of competition from the online retailer. Stocks of drug distributors McKesson , AmerisourceBergen and Cardinal Health rose 2 to 3 percent, while drugstore chains Walgreens Boots Alliance and CVS Health each advanced about 5 percent. Healthcare investors expect Amazon will become a major force in the industry, fueled by recent media reports that the Seattle-based company was considering entering the pharmacy business.