"Regulatory exclusivities provide incentives for pharmaceutical innovation in the United States. Overseen by the Food and Drug Administration (FDA), regulatory exclusivities are alternatively known as marketing exclusivities, data exclusivities, or data protection. Each of the distinct regulatory exclusivities establishes a period of time during which the FDA affords an approved drug protection from competing applications for marketing approval."
CRS Report for Congress, R44951
Federation of American Scientists: http://www.fas.org/sgp/crs/index.html