Developing medicines intended for small numbers of patients has little commercial incentive under normal market conditions. The regulatory agencies offer a range of incentives to encourage the development of designated orphan medicines. The Orphan Drug Designation (ODD) criteria varies according to the regulatory bodies who grant the status of orphan drug. In EU, Sponsors who obtain orphan designation benefit from protocol assistance, a type of scientific advice specific for designated orphan medicines, market exclusivity once the medicine is on the market, fee reductions depending on the status of the sponsor and the type of service required. For more information see the following resources