Halozyme "can directly address the questions raised by," the FDA, Gregory Frost, president and chief executive officer, of the company, said in the statement. The primary concern is the product's potential effect on reproduction, development and fertility, according to the statement. Baxter, based in Deerfield, Illinois, fell 1.2 percent to $57.95. The trial stopped by the agency combined the product made by San Diego-based Halozyme with ViroPharma Inc.'s Cinryze because of safety concerns, Exton, Pennsylvania-based ViroPharma said in a statement. Halozyme also must provide the FDA results from added pre-clinical tests before the trials can resume. ViroPharma is preparing to begin a trial that will evaluate the safety and efficacy of two different doses of Cinryze as a standalone therapy, the company said. Cinryze treats hereditary angioedema, which is a disease that causes severe swelling in the limbs, face, intestinal tract and airway.